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Kubernetes Version Features and Roadmap

サポート対象バージョン: Kubernetes 1.29 - 1.36 最終更新: July 3, 2026

Kubernetes は急速に進化しており、年 3 回の release で新機能の導入、既存機能の昇格、古い API の非推奨化が行われます。Amazon EKS を運用する enterprise team にとって、version landscape を理解することは、upgrade 計画、適切なタイミングでの新機能採用、deprecation による中断回避に不可欠です。この document は、Kubernetes 1.29 から 1.36 までを version ごとに包括的に参照できるようにし、各 release に対する EKS 固有の guidance を提供します。

Table of Contents

  1. Overview and Learning Objectives
  2. Kubernetes Release Cycle
  3. EKS Version Support Matrix
  4. Version-by-Version Feature Guide
  5. Key Feature Graduation Timeline
  6. Deprecations and Removals
  7. EKS-Specific Considerations
  8. Version Upgrade Planning
  9. Future Outlook
  10. References

1. Overview and Learning Objectives

Purpose of This Document

この document は、以下の中央集約された reference として機能します。

  • Kubernetes 1.29 から 1.36 で導入された version-specific new features
  • alpha から beta、GA への進行を追跡する feature graduation timelines
  • Deprecation schedules と必要な migration actions
  • standard support と extended support の日付を含む EKS support windows
  • enterprise team 向けの upgrade planning guidance

Learning Objectives

この document を読むと、以下ができるようになります。

  1. Kubernetes release cycle と feature maturity model を説明する
  2. 各 Kubernetes version で利用可能な feature を特定する
  3. feature gate を特定の version に対応付け、その lifecycle を理解する
  4. feature availability と deprecation timeline に基づいて version upgrade を計画する
  5. standard support と extended support を含む、EKS 固有の version support policy を理解する
  6. 古い version に留まることによる cost と risk の trade-off を評価する
  7. 今後登場する feature と予想される graduation timeline を見通す

Who Should Read This

AudienceKey Sections
Platform EngineersVersion Feature Guide, Upgrade Planning, Deprecations
Cluster AdministratorsEKS Support Matrix, Upgrade Planning, EKS-Specific Considerations
Application DevelopersFeature Guide (Sidecar Containers, In-Place Resize, DRA), Feature Graduation Timeline
Security TeamsDeprecations, Security-related features per version, StructuredAuthz, User Namespaces
Engineering ManagersOverview, Support Matrix, Cost implications of Extended Support

2. Kubernetes Release Cycle

Release Cadence

Kubernetes は予測可能な release cadence に従っており、おおよそ 4 か月間隔で年 3 回 release されます。

Typical Release Timeline

各 release は、約 15 週間にわたる構造化された timeline に従います。

PhaseDurationDescription
Enhancements FreezeWeek 0すべての feature に承認済み KEP (Kubernetes Enhancement Proposals) が必要
Code Freeze~Week 10新規 feature code は不可。bug fix と test に集中
Beta Release~Week 11testing 用の pre-release
RC (Release Candidate)~Week 13最終 testing phase
General Availability~Week 15公式 release

Feature Maturity Model

Kubernetes はすべての feature に対して 3 段階の graduation model を使用します。production planning では、これらの stage を理解することが重要です。

把握しておくべき重要な policy 変更:

  • Kubernetes 1.24 以降: Beta API は新規 cluster で default enabled ではなくなりました。新しい beta feature は feature gate による明示的な opt-in が必要です。
  • Kubernetes 1.28 以降: GA feature の feature gate は 2 release 後に削除されます。つまり、その feature は恒久的に enabled になります。

Feature Gates

Feature gate は、feature を enabled または disabled にするかを制御する key-value pair です。alpha/beta/GA maturity model を適用する mechanism です。

yaml
# Example: Enabling feature gates on the kubelet
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
featureGates:
  InPlacePodVerticalScaling: true    # Enable in-place pod resize (beta in 1.33)
  UserNamespacesSupport: true         # Enable user namespaces (beta in 1.33)
yaml
# Example: Enabling feature gates on the API server (EKS managed - informational only)
# Note: In EKS, control plane feature gates are managed by AWS.
# You cannot directly modify API server flags on EKS.
apiVersion: kubeadm.k8s.io/v1beta3
kind: ClusterConfiguration
apiServer:
  extraArgs:
    feature-gates: "ValidatingAdmissionPolicy=true,StructuredAuthorizationConfiguration=true"

cluster で enabled になっている feature gate の確認:

bash
# List all feature gates and their status on a node's kubelet
kubectl get --raw /api/v1/nodes/<node-name>/proxy/configz | jq '.kubeletconfig.featureGates'

# Check API server feature gates (requires API server access logs)
kubectl get --raw /metrics | grep kubernetes_feature_enabled

# Check specific feature gate status
kubectl get --raw /metrics | grep 'kubernetes_feature_enabled{name="InPlacePodVerticalScaling"}'

SIG Governance Structure

Kubernetes development は Special Interest Groups (SIGs) によって編成されています。どの SIG が feature を所有しているかを理解すると、進捗を追跡し、関連 documentation を見つけやすくなります。

SIGScopeKey Features in This Document
SIG NodeKubelet, container runtime, pod lifecycleSidecar Containers, In-Place Pod Resize, User Namespaces
SIG AuthAuthentication, authorization, security policyStructuredAuthorizationConfiguration, CEL Admission
SIG NetworkNetworking, Service, Ingress, DNSGateway API, ServiceCIDR/IPAddress, Topology Aware Routing
SIG StoragePV/PVC, CSI, volume managementVolumeAttributesClass, ReadWriteOncePod
SIG SchedulingScheduler, Pod Scheduling ReadinessPod Scheduling Readiness, Gang Scheduling
SIG AppsWorkload controllers (Deployment, StatefulSet, Job)Job Success Policy, Sidecar Containers
SIG API MachineryAPI server, CRDs, admission controlCEL Admission, KYAML
SIG AutoscalingHPA, VPA, cluster autoscalingHPA Container Resource Metrics

3. EKS Version Support Matrix

Support Tiers

Amazon EKS は 2 つの version support tier を提供します。

TierDurationPricingDescription
Standard SupportEKS release から 14 か月$0.10/cluster/hour完全な feature support、security patch、bug fix
Extended Support追加 12 か月$0.60/cluster/hoursecurity patch と critical bug fix のみ

Cost Impact: Extended support は standard support の 6 倍の費用です。単一 cluster を 24/7 で稼働させる場合、extended support は年間約 $4,380、standard support は年間約 $730 となり、cluster あたり年間 $3,650 の追加費用になります。

Version Lifecycle Diagram

Detailed Version Support Matrix

以下の table は、upstream release date、EKS availability、support end date を含む、EKS が support する各 Kubernetes version を追跡します。

K8s VersionCode NameUpstream ReleaseEKS ReleaseStandard Support EndExtended Support EndCurrent Status
1.29MandalaDec 2023Jun 2024Aug 2025Aug 2026Extended Support
1.30UwubernetesApr 2024Sep 2024Nov 2025Nov 2026Extended Support
1.31ElliAug 2024Dec 2024Feb 2026Feb 2027Extended Support
1.32PenelopeDec 2024Mar 2025May 2026May 2027Standard Support
1.33OctarineApr 2025Jun 2025Aug 2026Aug 2027Standard Support
1.34Of Wind & WillAug 2025Oct 2025Dec 2026Dec 2027Standard Support
1.35TimbernetesDec 2025Feb 2026Apr 2027Apr 2028Standard Support
1.36ハル (Haru)Apr 2026Jun 2026Aug 2027Aug 2028Standard Support

Note: EKS release date は通常、upstream Kubernetes release から 2〜4 か月遅れます。AWS はこの期間を使って release を検証し、EKS-managed add-ons と統合し、AWS services との compatibility を確認します。

Auto-Upgrade Behavior

Kubernetes version が support end(extended support を含む)に到達すると、EKS は cluster を自動的に upgrade します。

Important: Auto-upgrade は control plane のみを update します。node group、add-on、self-managed component は引き続き手動で upgrade する必要があります。対応する node と add-on の upgrade なしに control plane が強制 upgrade されると、workload disruption が発生する可能性があります。

Recent EKS Version Support Announcements (2026)

AWS は 2026 年に、EKS version support に影響する複数の announcement を行いました。

DateAnnouncementHighlights
2026-06-02EKS & EKS Distro begin supporting Kubernetes 1.36User Namespaces GA, Mutating Admission Policies, In-Place Pod Vertical Scaling, Resource Health Status, EKS Cluster Insights pre-upgrade checks
2026-01-28EKS & EKS Distro begin supporting Kubernetes 1.35In-Place Pod Resource Updates, PreferSameNode Traffic Distribution, Node Topology Labels via Downward API, Image Volumes

Kubernetes 1.36 Support (June 2, 2026)

Amazon EKS と EKS Distro は Kubernetes 1.36 の support を開始しました。この announcement では以下が強調されています(implementation detail は下の section 4.8 を参照)。

  • User Namespaces (GA): container の root user を host の non-privileged user に map し、multi-tenant isolation を強化
  • Mutating Admission Policies: webhook server 不要の CEL-based mutation
  • In-Place Pod Vertical Scaling: pod を restart せずに CPU/memory を調整
  • Resource Health Status: Pod status に device health と hardware failure condition を表示
  • EKS Cluster Insights: deprecated API usage と add-on compatibility の pre-upgrade check

Source: Amazon EKS Distro now supports Kubernetes version 1.36

Kubernetes 1.35 Support (January 28, 2026)

Amazon EKS と EKS Distro は Kubernetes 1.35 の support を開始し、以下を追加しました。

  • In-Place Pod Resource Updates -- section 4.7 で In-Place Pod Vertical Scaling GA として扱う、restart-free resource adjustment と同じ capability
  • PreferSameNode Traffic Distribution -- same node 上の endpoint へ traffic を route することを優先
  • Node Topology Labels via Downward API -- node topology label を pod に公開
  • Image Volumes -- OCI image を volume として mount し、data や ML model を配布

Source: Amazon EKS Distro now supports Kubernetes version 1.35

Related announcements: EKS version rollback support (July 1, 2026) と新しい control plane 99.99% SLA / 8XL scaling tier (March 20, 2026) は、Kubernetes version feature ではなく upgrade process に直接関係するため、EKS Upgrades document で扱います。


4. Version-by-Version Feature Guide

この section では、Kubernetes 1.29 から 1.36 までの各 version で導入、graduated、deprecated された feature を詳細に説明します。

4.1 Kubernetes 1.29 "Mandala" (December 2023)

Theme: 宇宙を象徴する幾何学的 art form にちなんだ名称で、この release に対する community の holistic approach を反映しています。

Release Stats: 49 enhancements -- 11 Stable, 19 Beta, 19 Alpha

Key Graduated Features (GA)

KMS v2 Encryption

Kubernetes Secrets の at-rest encryption 向け KMS v2 が GA に到達し、KMS v1 と比べて大幅な performance improvement を提供します。

AspectKMS v1KMS v2
Encryption calls per writeobject ごとに 1 回DEK rotation ごとに 1 回
Performancescale 時に high latencyほぼ constant latency
Key hierarchysingle layertwo-layer (KEK + DEK)
Status1.28 で deprecated1.29 で GA
yaml
# KMS v2 EncryptionConfiguration
apiVersion: apiserver.config.k8s.io/v1
kind: EncryptionConfiguration
resources:
  - resources:
      - secrets
    providers:
      - kms:
          apiVersion: v2
          name: aws-encryption-provider
          endpoint: unix:///var/run/kmsplugin/socket.sock
          timeout: 3s
      - identity: {}

ReadWriteOncePod PV Access Mode

ReadWriteOncePod (RWOP) access mode が GA に昇格しました。これにより、PersistentVolume は cluster 全体で単一の Pod からのみ read-write として mount できるようになり、ReadWriteOnce(同じ node 上の複数 pod を許可)より強い data safety guarantee を提供します。

yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: database-pvc
spec:
  accessModes:
    - ReadWriteOncePod    # Only one pod can mount this volume
  storageClassName: gp3
  resources:
    requests:
      storage: 100Gi

Other GA Features in 1.29:

  • credential を使った CSI volume expansion 用の NodeExpandSecret
  • kubelet-level distributed tracing 用の KubeletTracing
  • ReadWriteOncePod PersistentVolume access mode
  • topology spread constraint 用の MinDomainsInPodTopologySpread

Key Beta Features

nftables-based kube-proxy (Alpha)

iptables の代わりに nftables を使用する新しい kube-proxy backend が alpha として導入されました。nftables は、特に数千の Services を持つ cluster で iptables より優れた performance と scalability を提供するため重要です。

bash
# Check current kube-proxy mode
kubectl get configmap kube-proxy-config -n kube-system -o yaml | grep mode

# nftables mode (alpha in 1.29 - requires feature gate)
# mode: nftables
Proxy ModeMaturity in 1.29Rule ComplexityPerformance at Scale
iptablesStable (default)packet ごとに O(n)>5000 services で低下
IPVSStableO(1) lookupscale 時に良好
nftablesAlphaO(1) lookupscale 時に非常に良好

Load Balancer IP Mode

LoadBalancerIPMode feature (beta) により、type LoadBalancer の Services が load balancer IP の扱いを指定できるようになり、cloud provider implementation との compatibility が向上します。

Key Alpha Features

  • SidecarContainers (restartPolicy: Always を持つ initContainer) -- その旅を始めた landmark feature
  • PodLifecycleSleepAction -- pod lifecycle hook に sleep action を追加
  • Unknown Version Interoperability Proxy -- unknown API version への request を proxy

Deprecations in 1.29

  • flowcontrol.apiserver.k8s.io/v1beta2 deprecated (1.32 で removed)
  • SecurityContextDeny admission plugin deprecated
  • In-tree cloud provider integration は deprecation path を継続

4.2 Kubernetes 1.30 "Uwubernetes" (April 2024)

Theme: Kubernetes community の welcoming な性質を体現する、community が選んだ playful な名称です。

Release Stats: 45 enhancements -- 17 Stable, 18 Beta, 10 Alpha

Key Graduated Features (GA)

ValidatingAdmissionPolicy with CEL (GA)

最も重要な graduating feature の 1 つである ValidatingAdmissionPolicy は、Common Expression Language (CEL) を使った native admission control を可能にし、多くの use case で webhook-based admission controller を不要にします。

AspectAdmission WebhooksValidatingAdmissionPolicy (CEL)
Latencynetwork round-tripin-process evaluation
Availability riskwebhook server failure = blocked requestsexternal dependency なし
LanguageAny (Go, Python, etc.)CEL
Complexity高い (deploy, maintain, scale)低い (single YAML resource)
Feature journeyN/AAlpha 1.26 -> Beta 1.28 -> GA 1.30
yaml
# ValidatingAdmissionPolicy: Require resource limits on all containers
apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingAdmissionPolicy
metadata:
  name: require-resource-limits
spec:
  failurePolicy: Fail
  matchConstraints:
    resourceRules:
      - apiGroups: [""]
        apiVersions: ["v1"]
        operations: ["CREATE", "UPDATE"]
        resources: ["pods"]
  validations:
    - expression: >-
        object.spec.containers.all(c,
          has(c.resources) &&
          has(c.resources.limits) &&
          has(c.resources.limits.memory) &&
          has(c.resources.limits.cpu)
        )
      message: "All containers must have CPU and memory limits set"
      reason: Invalid
---
apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingAdmissionPolicyBinding
metadata:
  name: require-resource-limits-binding
spec:
  policyName: require-resource-limits
  validationActions:
    - Deny
  matchResources:
    namespaceSelector:
      matchLabels:
        enforce-limits: "true"
yaml
# CEL: Enforce image registry policy
apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingAdmissionPolicy
metadata:
  name: restrict-image-registries
spec:
  failurePolicy: Fail
  matchConstraints:
    resourceRules:
      - apiGroups: [""]
        apiVersions: ["v1"]
        operations: ["CREATE", "UPDATE"]
        resources: ["pods"]
  validations:
    - expression: >-
        object.spec.containers.all(c,
          c.image.startsWith('123456789012.dkr.ecr.') ||
          c.image.startsWith('public.ecr.aws/')
        )
      message: "Images must come from approved ECR registries"
    - expression: >-
        object.spec.initContainers.all(c,
          c.image.startsWith('123456789012.dkr.ecr.') ||
          c.image.startsWith('public.ecr.aws/')
        )
      message: "Init container images must come from approved ECR registries"

Pod Scheduling Readiness (GA)

Pod Scheduling Readiness により、特定条件が満たされるまで pod を作成しても scheduling されないようにできます。これにより pod creation と scheduling が分離され、batch scheduling や resource provisioning のような advanced workflow が可能になります。

yaml
# Pod with scheduling gates
apiVersion: v1
kind: Pod
metadata:
  name: ml-training-job
spec:
  schedulingGates:
    - name: "example.com/gpu-provisioned"      # Gate 1: Wait for GPU node
    - name: "example.com/dataset-downloaded"    # Gate 2: Wait for data
  containers:
    - name: trainer
      image: ml-training:v2
      resources:
        limits:
          nvidia.com/gpu: 4
bash
# Remove a scheduling gate when the condition is met
kubectl patch pod ml-training-job --type='json' -p='[
  {"op": "remove", "path": "/spec/schedulingGates/0"}
]'

# Check remaining scheduling gates
kubectl get pod ml-training-job -o jsonpath='{.spec.schedulingGates}'

HPA ContainerResource Metrics (GA)

HPA は total pod metrics ではなく個々の container metrics に基づいて scale できるようになりました。これは、main container の resource usage が scaling を駆動すべきで、sidecar を含む合計ではない sidecar pattern で重要です。

yaml
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: web-app-hpa
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: web-app
  minReplicas: 2
  maxReplicas: 50
  metrics:
    - type: ContainerResource
      containerResource:
        name: cpu
        container: app              # Scale based only on the 'app' container
        target:
          type: Utilization
          averageUtilization: 70
    - type: ContainerResource
      containerResource:
        name: memory
        container: app              # Ignore sidecar memory usage
        target:
          type: Utilization
          averageUtilization: 80

Other GA Features in 1.30:

  • MinDomainsInPodTopologySpread -- topology spread の minimum domain count
  • NodeLogQuery -- kubelet API 経由で node-level logs を query
  • PodDisruptionConditions -- Pod status に disruption-related condition を追加
  • StableLoadBalancerNodeSet -- load balancer health check 用の stable set of nodes

Key Beta Features

Contextual Logging (Beta, Enabled by Default)

Contextual logging は、pod name、namespace、component などの structured context をすべての Kubernetes log message に追加し、log analysis と correlation を大幅に容易にします。

bash
# Before contextual logging
I0415 12:00:00.000000       1 controller.go:100] "Reconciling object" name="my-pod"

# With contextual logging (additional context automatically added)
I0415 12:00:00.000000       1 controller.go:100] "Reconciling object" logger="pod-controller" pod="default/my-pod" node="ip-10-0-1-100"

Recursive Read-Only Mounts (Beta)

volume mount tree 全体を recursive に read-only にでき、read-only mount path 内の writable sub-mount を防ぎます。

Key Alpha Features

  • UserNamespacesSupport -- security isolation 向上のための pod-level user namespaces
  • RelaxedEnvironmentVariableValidation -- env var value で従来 invalid だった文字を許可
  • SELinuxMountReadWriteOncePod -- RWOP volume 向け SELinux label support

4.3 Kubernetes 1.31 "Elli" (August 2024)

Theme: Kubernetes contributor の犬にちなんだ名称で、community の personal touch を反映しています。

Release Stats: 45 enhancements -- 11 Stable, 22 Beta, 12 Alpha

Key Graduated Features (GA)

AppArmor Support (GA)

Kubernetes の native AppArmor support が GA に昇格し、従来の annotation-based approach を適切な API field に置き換えました。

yaml
# Old approach (deprecated annotations)
# metadata:
#   annotations:
#     container.apparmor.security.beta.kubernetes.io/app: localhost/my-profile

# New GA approach: native API field
apiVersion: v1
kind: Pod
metadata:
  name: secure-app
spec:
  containers:
    - name: app
      image: myapp:latest
      securityContext:
        appArmorProfile:
          type: Localhost
          localhostProfile: my-custom-profile
yaml
# AppArmor with RuntimeDefault profile
apiVersion: apps/v1
kind: Deployment
metadata:
  name: web-server
spec:
  template:
    spec:
      containers:
        - name: nginx
          image: nginx:1.27
          securityContext:
            appArmorProfile:
              type: RuntimeDefault    # Uses container runtime's default profile

Persistent Volume Last Phase Transition Time (GA)

PersistentVolumes 上の新しい .status.lastPhaseTransitionTime field が、PV が最後に phase(Available, Bound, Released, Failed)を変更した時刻を追跡します。これにより volume lifecycle に関する monitoring と automation が向上します。

bash
# Check PV phase transition times
kubectl get pv -o custom-columns=\
NAME:.metadata.name,\
PHASE:.status.phase,\
LAST_TRANSITION:.status.lastPhaseTransitionTime

# Example output:
# NAME         PHASE     LAST_TRANSITION
# pv-data-01   Bound     2025-01-15T10:30:00Z
# pv-data-02   Released  2025-01-14T22:15:00Z

Other GA Features in 1.31:

  • PodDisruptionConditions -- disruption cause information で強化された Pod status
  • JobPodReplacementPolicy -- Jobs で failed pod をいつ置き換えるかを制御
  • PodHostIPs -- downward API 経由で全 host IP(IPv4 と IPv6)を pod に公開

Key Beta Features

DRA Structured Parameters (Beta)

Dynamic Resource Allocation (DRA) structured parameters が beta に移行し、device plugin が standardized API を通じて hardware capability を advertise できるようになりました。これは GPU、FPGA、その他 accelerator scheduling の基盤です。

yaml
# ResourceClaim for GPU allocation using DRA
apiVersion: resource.k8s.io/v1beta1
kind: ResourceClaim
metadata:
  name: gpu-claim
spec:
  devices:
    requests:
      - name: gpu
        deviceClassName: gpu.nvidia.com
        selectors:
          - cel:
              expression: >-
                device.attributes["gpu.nvidia.com"].model == "A100" &&
                device.capacity["gpu.nvidia.com"].memory.compareTo(quantity("80Gi")) >= 0

Sidecar Containers (Beta)

sidecar containers feature は beta に進みました(1.29 で alpha、1.31 で default enabled)。restartPolicy: Always を持つ init containers は true sidecars として機能し、以下を実現します。

  • regular containers より前に start
  • main workload と並行して run
  • pod shutdown 時に最後に terminated
yaml
apiVersion: v1
kind: Pod
metadata:
  name: app-with-sidecar
spec:
  initContainers:
    - name: log-shipper
      image: fluent-bit:latest
      restartPolicy: Always       # This makes it a sidecar
      volumeMounts:
        - name: log-volume
          mountPath: /var/log/app
  containers:
    - name: app
      image: myapp:latest
      volumeMounts:
        - name: log-volume
          mountPath: /var/log/app
  volumes:
    - name: log-volume
      emptyDir: {}

Traffic Distribution for Services (Beta)

Services 上の新しい spec.trafficDistribution field により、same-zone endpoint を優先するなどの traffic routing preference を要求できます。

yaml
apiVersion: v1
kind: Service
metadata:
  name: my-service
spec:
  trafficDistribution: PreferClose    # Route traffic to closest endpoints
  selector:
    app: my-app
  ports:
    - port: 80
      targetPort: 8080

Other Beta Features in 1.31:

  • PodLifecycleSleepAction -- PreStop/PostStart hook の sleep action
  • RelaxedDNSSearchValidation -- DNS search path validation の緩和
  • VolumeAttributesClass -- CSI 経由の mutable volume attributes

Key Alpha Features

  • PortForwardWebsockets -- WebSocket-based port forwarding
  • ImageVolume -- OCI image を read-only volume として mount
  • DRAPartitionableDevices -- DRA device の partitioning support

4.4 Kubernetes 1.32 "Penelope" (December 2024)

Theme: Homer の Odyssey に登場する忠実な人物 Penelope にちなんだ名称で、project の揺るぎない reliability を象徴しています。

Release Stats: 44 enhancements -- 13 Stable, 12 Beta, 19 Alpha

Key Graduated Features (GA)

StructuredAuthorizationConfiguration (GA)

authorization module(Node, RBAC, Webhook, CEL)の ordered chain を structured configuration で定義できる major security feature です。legacy --authorization-mode flag approach を置き換えます。

yaml
# StructuredAuthorizationConfiguration
# (Managed by AWS for EKS control plane; shown for reference)
apiVersion: apiserver.config.k8s.io/v1beta1
kind: AuthorizationConfiguration
authorizers:
  - type: Node
    name: node
  - type: RBAC
    name: rbac
  - type: Webhook
    name: custom-authz
    webhook:
      timeout: 3s
      subjectAccessReviewVersion: v1
      matchConditionSubjectAccessReviewVersion: v1
      failurePolicy: Deny
      connectionInfo:
        type: KubeConfigFile
        kubeConfigFile: /etc/kubernetes/authz-webhook.kubeconfig
      matchConditions:
        - expression: >-
            request.resourceAttributes.namespace == "production"

これにより以下が可能になります。

  • Ordered evaluation: Authorization request を chain に沿って順番に評価
  • CEL-based filtering: CEL expression を使って各 authorizer に関連する request のみを match
  • Granular webhook routing: 特定の request のみを external authorization webhook に送信
  • Feature journey: Alpha 1.29 -> Beta 1.30 -> GA 1.32

Auto-Remove PVC Protection Finalizer (GA)

PersistentVolumeClaim protection finalizer は、PVC が使用されなくなると自動的に clean up されるようになりました。これにより、protection finalizer が削除されなかったために削除できない orphaned PVC という一般的な問題が解消されます。

bash
# Before 1.32: Common issue - stuck PVC deletion
$ kubectl delete pvc my-pvc
persistentvolumeclaim "my-pvc" deleted  # ... hangs forever

$ kubectl get pvc my-pvc -o jsonpath='{.metadata.finalizers}'
["kubernetes.io/pvc-protection"]  # Finalizer not removed

# After 1.32 (GA): Automatic cleanup
$ kubectl delete pvc my-pvc
persistentvolumeclaim "my-pvc" deleted  # Completes immediately when no pod references it

Other GA Features in 1.32:

  • CustomResourceFieldSelectors -- CRD 用 field selector
  • RetryGenerateName -- conflict 時に新しい generated name で自動 retry
  • SizeMemoryBackedVolumes -- memory-backed emptyDir volume の size limit を enforce
  • StableLoadBalancerNodeSet -- LB health checking 用の consistent node set
  • ServiceAccountTokenJTI -- audit tracking 用の SA token 内 unique JTI
  • ServiceAccountTokenNodeBindingValidation -- SA token を node に bind

Key Beta Features

User Namespaces (Beta)

User namespaces は、container 内の UID/GID を remap することで強力な security boundary を提供します。process が container 内で root として実行されていても、host 上では unprivileged user に map されます。

yaml
apiVersion: v1
kind: Pod
metadata:
  name: secure-pod
spec:
  hostUsers: false              # Enable user namespace remapping
  containers:
    - name: app
      image: myapp:latest
      securityContext:
        runAsUser: 0            # Root inside container
        # Maps to unprivileged UID on host (e.g., UID 65534+offset)

VolumeAttributesClass (Beta)

VolumeAttributesClass により、provisioning 後に volume を再作成せずに volume attributes(IOPS、throughput など)を変更できます。

yaml
apiVersion: storage.k8s.io/v1beta1
kind: VolumeAttributesClass
metadata:
  name: high-performance
driverName: ebs.csi.aws.com
parameters:
  iops: "10000"
  throughput: "500"
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: database-volume
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 500Gi
  storageClassName: gp3
  volumeAttributesClassName: high-performance    # Apply performance attributes
yaml
# Modify volume attributes by changing the class reference
# (triggers a CSI ModifyVolume call)
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: database-volume
spec:
  volumeAttributesClassName: ultra-performance   # Switch to higher tier

nftables kube-proxy (Beta)

kube-proxy の nftables backend が beta に進み、Service routing 向けの production-ready nftables support をもたらします。

Key Alpha Features

  • DynamicResourceAllocation (DRA) Core -- GPU/accelerator scheduling の包括的 framework
  • MultiCIDRServiceAllocator -- 複数の CIDR range から Service IP を allocate
  • RelaxedEnvironmentVariableValidation -- env var で使用可能な character set を拡張
  • InPlacePodVerticalScalingExtendedStatus -- pod resizing の extended status reporting

4.5 Kubernetes 1.33 "Octarine" (April 2025)

Theme: Terry Pratchett の Discworld series に登場する、wizard にしか見えない eighth color にちなんだ名称です。magical features が詰まった release にふさわしい名前です。

Release Stats: 64 enhancements -- 18 Stable, 20 Beta, 24 Alpha (この範囲で最大の release)

Key Graduated Features (GA)

Sidecar Containers (GA)

この release で最も期待された GA graduation です。restartPolicy: Always を持つ init containers として実装される native sidecar containers は、複数 version にわたる journey を経て full stability に到達しました。

VersionStatusBehavior
1.28AlphaFeature gate SidecarContainers required
1.29AlphaBug fixes, stability improvements
1.31BetaEnabled by default
1.33GAPermanently enabled, feature gate removed
yaml
# Production-ready sidecar pattern (GA in 1.33)
apiVersion: apps/v1
kind: Deployment
metadata:
  name: microservice
spec:
  replicas: 3
  selector:
    matchLabels:
      app: microservice
  template:
    metadata:
      labels:
        app: microservice
    spec:
      initContainers:
        # Sidecar 1: Service mesh proxy
        - name: envoy-proxy
          image: envoyproxy/envoy:v1.31
          restartPolicy: Always
          ports:
            - containerPort: 15001
          resources:
            requests:
              cpu: 100m
              memory: 128Mi
            limits:
              cpu: 500m
              memory: 256Mi

        # Sidecar 2: Log collection
        - name: fluent-bit
          image: fluent/fluent-bit:3.2
          restartPolicy: Always
          volumeMounts:
            - name: app-logs
              mountPath: /var/log/app
          resources:
            requests:
              cpu: 50m
              memory: 64Mi

        # Regular init container (runs to completion first)
        - name: db-migration
          image: myapp-migrations:latest
          command: ["./migrate", "--target", "latest"]

      containers:
        - name: app
          image: myapp:v3.2
          ports:
            - containerPort: 8080
          volumeMounts:
            - name: app-logs
              mountPath: /var/log/app

      volumes:
        - name: app-logs
          emptyDir: {}

Sidecar container lifecycle guarantees:

ServiceCIDR and IPAddress API (GA)

ServiceCIDR and IPAddress API により、cluster restart なしで Service IP range を dynamic に管理できます。これは初期 Service CIDR を使い切る large-scale cluster で特に有用です。

yaml
# Define additional Service CIDR ranges
apiVersion: networking.k8s.io/v1
kind: ServiceCIDR
metadata:
  name: secondary-service-range
spec:
  cidrs:
    - "10.200.0.0/16"
bash
# View allocated IP addresses
kubectl get ipaddresses

# Check ServiceCIDR status
kubectl get servicecidrs
NAME                       CIDRS            AGE
kubernetes                 10.96.0.0/12     365d
secondary-service-range    10.200.0.0/16    30d

Topology Aware Routing (GA)

以前は "Topology Aware Hints" として知られていたこの feature は、"Topology Aware Routing" という名称で GA に昇格しました。同じ availability zone 内の endpoint へ Service traffic を preferential routing でき、cross-AZ data transfer cost を削減します。

yaml
apiVersion: v1
kind: Service
metadata:
  name: my-service
  annotations:
    # Legacy hint-based approach (deprecated)
    # service.kubernetes.io/topology-aware-hints: Auto
spec:
  trafficDistribution: PreferClose    # GA approach in 1.33
  selector:
    app: my-app
  ports:
    - port: 80
      targetPort: 8080

EKS Cost Tip: high-traffic internal services で topology-aware routing を有効化すると、AWS の same region 内で $0.01/GB の cross-AZ data transfer charge を大幅に削減できます。

Job Success Policy (GA)

すべての pod が完了していなくても Job を successful とみなす条件を指定できます。leader pod の success が全体の job success を決める distributed computing framework に不可欠です。

yaml
apiVersion: batch/v1
kind: Job
metadata:
  name: distributed-training
spec:
  completionMode: Indexed
  completions: 8
  parallelism: 8
  successPolicy:
    rules:
      - succeededIndexes: "0"       # Job succeeds when index 0 (leader) succeeds
        succeededCount: 1
  template:
    spec:
      containers:
        - name: trainer
          image: pytorch-training:latest
          env:
            - name: JOB_COMPLETION_INDEX
              valueFrom:
                fieldRef:
                  fieldPath: metadata.annotations['batch.kubernetes.io/job-completion-index']

Other GA Features in 1.33:

  • PodLifecycleSleepAction -- pod lifecycle hook の sleep action
  • LoadBalancerIPMode -- LB IP が pod にどう見えるかを制御
  • JobManagedBy -- Job object の external controller management
  • RetryGenerateName -- generated name の automatic name collision retry

Key Beta Features (Enabled by Default)

In-Place Pod Vertical Scaling (Beta)

Kubernetes history で最も期待された feature の 1 つです。in-place pod resize により、running pod を restart せずに CPU と memory resources を変更できます。

yaml
apiVersion: v1
kind: Pod
metadata:
  name: resizable-app
spec:
  containers:
    - name: app
      image: myapp:latest
      resources:
        requests:
          cpu: 500m
          memory: 256Mi
        limits:
          cpu: "1"
          memory: 512Mi
      resizePolicy:
        - resourceName: cpu
          restartPolicy: NotRequired    # CPU resize without restart
        - resourceName: memory
          restartPolicy: RestartContainer  # Memory resize requires restart
bash
# Resize a running pod's CPU (no restart!)
kubectl patch pod resizable-app --subresource resize --patch '{
  "spec": {
    "containers": [{
      "name": "app",
      "resources": {
        "requests": {"cpu": "1"},
        "limits": {"cpu": "2"}
      }
    }]
  }
}'

# Check resize status
kubectl get pod resizable-app -o jsonpath='{.status.resize}'
# "InProgress" -> "Proposed" -> "" (completed)

# View allocated vs requested resources
kubectl get pod resizable-app -o jsonpath='{.status.containerStatuses[0].allocatedResources}'
Feature JourneyVersionNotes
Alpha1.27Initial implementation
Beta1.33Enabled by default
GA1.35Full stability

OCI Images as Volumes (Beta)

OCI (Open Container Initiative) image を pod 内に read-only volume として直接 mount できます。これにより data、ML model、configuration を application image に bundle せずに container image として共有できます。

yaml
apiVersion: v1
kind: Pod
metadata:
  name: ml-inference
spec:
  containers:
    - name: inference-server
      image: inference-engine:latest
      volumeMounts:
        - name: model
          mountPath: /models/llama
          readOnly: true
  volumes:
    - name: model
      image:
        reference: 123456789012.dkr.ecr.us-west-2.amazonaws.com/models:llama-7b
        pullPolicy: IfNotPresent

User Namespaces (Beta)

User namespaces は beta に進み、container process が host 上の unprivileged user に map される、より強力な security isolation を提供します。

Other Beta Features in 1.33:

  • MatchLabelKeysInPodAffinity -- pod affinity matching に label key を使用
  • PodLevelResources -- container level だけでなく pod level で resource limit を設定
  • ServiceTrafficDistribution -- enhanced traffic distribution controls
  • StructuredAuthenticationConfiguration -- authz pattern に対応する structured authn config

Key Alpha Features

  • KYAML -- dangerous YAML feature を制限する、より安全な YAML subset
  • PortForwardWebsockets improvements
  • CRDValidationRatcheting enhancements -- 既存の invalid field を validation に通過させる
  • MutatingAdmissionPolicy -- CEL-based mutating admission(ValidatingAdmissionPolicy の counterpart)

4.6 Kubernetes 1.34 "Of Wind & Will" (August 2025)

Theme: Kubernetes project を前進させる momentum と determination を捉えた evocative な名称です。

Release Stats: 58 enhancements -- 23 Stable, 22 Beta, 13 Alpha

Key Graduated Features (GA)

Dynamic Resource Allocation (DRA) Core APIs (GA)

DRA は GA に到達し、GPU、FPGA、network device などの hardware resource を request および allocate する standardized framework を提供します。これは legacy device plugin model を、より flexible で Kubernetes-native な approach に置き換えます。

yaml
# DeviceClass: Define a class of hardware devices
apiVersion: resource.k8s.io/v1
kind: DeviceClass
metadata:
  name: gpu-a100
spec:
  selectors:
    - cel:
        expression: >-
          device.driver == "gpu.nvidia.com" &&
          device.attributes["model"].stringValue == "A100"
---
# ResourceClaim: Request specific hardware
apiVersion: resource.k8s.io/v1
kind: ResourceClaim
metadata:
  name: training-gpus
  namespace: ml-team
spec:
  devices:
    requests:
      - name: gpu
        deviceClassName: gpu-a100
        count: 4
    constraints:
      - requests: ["gpu"]
        matchAttribute: "gpu.nvidia.com/numa-node"    # All GPUs on same NUMA node
---
# ResourceClaimTemplate: Auto-create claims per pod
apiVersion: resource.k8s.io/v1
kind: ResourceClaimTemplate
metadata:
  name: gpu-claim-template
  namespace: ml-team
spec:
  spec:
    devices:
      requests:
        - name: gpu
          deviceClassName: gpu-a100
          count: 1
---
# Pod using DRA
apiVersion: v1
kind: Pod
metadata:
  name: ml-training
  namespace: ml-team
spec:
  resourceClaims:
    - name: gpu-claim
      resourceClaimName: training-gpus
  containers:
    - name: trainer
      image: pytorch-training:latest
      resources:
        claims:
          - name: gpu-claim
            request: gpu

Namespace Structured Deletion (GA)

Namespace deletion は well-defined ordering に従うようになり、依存される resource より前に dependent resource が clean up されることを保証します。これにより、長年存在した stuck-namespace issue の class が解消されます。

bash
# Before 1.34: Namespace deletion could get stuck
$ kubectl delete namespace old-project
# Hangs indefinitely due to finalizer ordering issues

# After 1.34 (GA): Ordered deletion with clear status
$ kubectl delete namespace old-project
$ kubectl get namespace old-project -o jsonpath='{.status.conditions}'
# Shows clear progress through deletion phases

VolumeAttributesClass (GA)

VolumeAttributesClass が GA に昇格し、IOPS や throughput などの volume attributes を in-place で変更できるようになりました。

yaml
# Change EBS volume performance tier without recreating
apiVersion: storage.k8s.io/v1
kind: VolumeAttributesClass
metadata:
  name: high-iops
driverName: ebs.csi.aws.com
parameters:
  iops: "16000"
  throughput: "1000"
---
apiVersion: storage.k8s.io/v1
kind: VolumeAttributesClass
metadata:
  name: standard
driverName: ebs.csi.aws.com
parameters:
  iops: "3000"
  throughput: "125"
bash
# Switch a PVC's performance tier
kubectl patch pvc database-vol --type='merge' -p '{
  "spec": {"volumeAttributesClassName": "high-iops"}
}'

# Monitor the modification
kubectl get pvc database-vol -o jsonpath='{.status.currentVolumeAttributesClassName}'
kubectl get pvc database-vol -o jsonpath='{.status.modifyVolumeStatus}'

Other GA Features in 1.34:

  • nftablesProxyMode -- nftables kube-proxy backend
  • Services 向け TrafficDistribution
  • PodLevelResources -- pod level で aggregate resource limits を設定
  • MatchLabelKeysInPodAffinity -- label-key-based affinity matching
  • ImageVolume -- OCI images as volumes
  • UserNamespacesSupport -- user namespace isolation

Key Beta Features

KYAML (Beta, Enabled by Default)

KYAML は Kubernetes manifest 向けに設計された、より安全な YAML subset です。anchors、aliases、特定の type coercion など、security vulnerability や unexpected behavior につながる dangerous YAML feature を disallow します。

yaml
# STANDARD YAML: These dangerous patterns are REJECTED by KYAML

# Pattern 1: YAML anchors and aliases (disabled in KYAML)
# defaults: &defaults
#   replicas: 3
# production:
#   <<: *defaults     # REJECTED: anchor/alias

# Pattern 2: Boolean coercion (restricted in KYAML)
# environment: yes    # YAML interprets as boolean True
# environment: "yes"  # KYAML requires explicit quoting

# Pattern 3: Octal notation ambiguity
# fileMode: 0644      # YAML may interpret as octal or decimal
# fileMode: "0644"    # KYAML requires clarity
bash
# Check if KYAML validation is enabled on your cluster
kubectl get --raw /metrics | grep kyaml_validation

# Test a manifest against KYAML rules
kubectl apply --dry-run=server -f manifest.yaml
# Warnings will indicate KYAML violations

MutatingAdmissionPolicy (Beta)

ValidatingAdmissionPolicy の CEL-based counterpart であり、webhook なしで admission 中に resource を in-line mutation できます。

yaml
apiVersion: admissionregistration.k8s.io/v1beta1
kind: MutatingAdmissionPolicy
metadata:
  name: inject-default-labels
spec:
  matchConstraints:
    resourceRules:
      - apiGroups: ["apps"]
        apiVersions: ["v1"]
        operations: ["CREATE"]
        resources: ["deployments"]
  mutations:
    - patchType: ApplyConfiguration
      applyConfiguration:
        expression: >-
          Object{
            metadata: Object.metadata{
              labels: {
                "app.kubernetes.io/managed-by": "platform-team",
                "cost-center": string(request.namespace)
              }
            }
          }

Other Beta Features in 1.34:

  • CRDValidationRatcheting -- CRD field の progressive validation
  • DeviceHealthConditions -- DRA 経由で device health を report
  • PodLevelResources enhancements

Key Alpha Features

  • KYAML はこの release で alpha から beta に移行
  • GangScheduling (alpha) -- pod の group を atomic に schedule
  • InPlacePodVerticalScaling extended features
  • DRAPartitionableDevices improvements

4.7 Kubernetes 1.35 "Timbernetes" (December 2025)

Theme: complexity を切り開き、solid foundation を築くという release の focus を反映した lumberjack-themed name です。

Release Stats: 60 enhancements -- 17 Stable, 19 Beta, 22 Alpha

Key Graduated Features (GA)

In-Place Pod Vertical Scaling (GA)

長く待たれていた in-place pod resize の graduation です。Pod は full stability guarantee のもとで、restart なしに CPU と memory を resize できるようになりました。

VersionStatusKey Changes
1.27AlphaInitial implementation, CPU-only resize
1.33BetaMemory resize, resize policies, enabled by default
1.35GAFull stability, extended status, production-ready
yaml
# Production-ready in-place scaling with VPA integration
apiVersion: autoscaling.k8s.io/v1
kind: VerticalPodAutoscaler
metadata:
  name: app-vpa
spec:
  targetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: web-app
  updatePolicy:
    updateMode: "InPlace"           # Use in-place resize (requires 1.35+)
  resourcePolicy:
    containerPolicies:
      - containerName: app
        minAllowed:
          cpu: 100m
          memory: 128Mi
        maxAllowed:
          cpu: "4"
          memory: 4Gi
        controlledResources:
          - cpu
          - memory
yaml
# Resize policy controlling restart behavior
apiVersion: v1
kind: Pod
metadata:
  name: production-app
spec:
  containers:
    - name: app
      image: myapp:latest
      resources:
        requests:
          cpu: "1"
          memory: 1Gi
        limits:
          cpu: "2"
          memory: 2Gi
      resizePolicy:
        - resourceName: cpu
          restartPolicy: NotRequired       # CPU: resize in-place
        - resourceName: memory
          restartPolicy: NotRequired       # Memory: also in-place (GA!)
bash
# Resize workflow
kubectl patch pod production-app --subresource resize --patch '{
  "spec": {
    "containers": [{
      "name": "app",
      "resources": {
        "requests": {"cpu": "2", "memory": "2Gi"},
        "limits": {"cpu": "4", "memory": "4Gi"}
      }
    }]
  }
}'

# Monitor resize progress
kubectl get pod production-app -o json | jq '{
  resize: .status.resize,
  allocated: .status.containerStatuses[0].allocatedResources,
  requested: .spec.containers[0].resources.requests
}'

Impact for EKS Users: In-place pod resize は resource adjustment のために pod を restart する必要をなくします。これは以下に transformative です。

  • restart cost が高い Stateful workloads (databases, caches)
  • 実行中に追加 resource を必要とする Long-running batch jobs
  • 以前は pod restart が必要だった VPA adoption
  • disruption なしの right-sizing による Cost optimization

Other GA Features in 1.35:

  • CRDValidationRatcheting -- progressive CRD validation
  • DeviceHealthConditions -- DRA device health reporting
  • PodLifecycleSleepActionGracePeriod -- sleep action 向け configurable grace period
  • ContextualLogging -- fully graduated structured logging

Key Beta Features

KYAML (Beta, Enabled by Default)

KYAML は beta に到達して default enabled になり、API server に送信されるすべての YAML がより安全な subset に対して validated されます。invalid YAML pattern は warning を生成します(beta では rejection ではありません)。

bash
# With KYAML enabled, these warnings appear on apply:
$ kubectl apply -f deployment.yaml
Warning: KYAML: line 15: implicit boolean coercion; use "true" instead of "yes"
Warning: KYAML: line 23: YAML anchor detected; anchors are not supported in KYAML
deployment.apps/my-app created

Gang Scheduling (Alpha moving to Beta)

Gang scheduling は、pod group が atomic に schedule されることを保証します。つまり group 内のすべての pod が schedule されるか、どれも schedule されないかのどちらかです。これは distributed training や tightly-coupled HPC workloads に重要です。

yaml
# PodGroup for gang scheduling
apiVersion: scheduling.k8s.io/v1alpha1
kind: PodGroup
metadata:
  name: distributed-training
  namespace: ml-team
spec:
  minMember: 4                    # All 4 pods must be schedulable
  scheduleTimeoutSeconds: 300     # Timeout if group can't be scheduled
---
apiVersion: batch/v1
kind: Job
metadata:
  name: pytorch-distributed
  namespace: ml-team
spec:
  completions: 4
  parallelism: 4
  template:
    metadata:
      labels:
        pod-group.scheduling.k8s.io/name: distributed-training
    spec:
      schedulerName: default-scheduler
      containers:
        - name: trainer
          image: pytorch-dist:latest
          resources:
            limits:
              nvidia.com/gpu: 8

Other Beta Features in 1.35:

  • AnonymousAuthConfigurableEndpoints -- endpoint ごとの configurable anonymous access
  • InPlacePodVerticalScalingAllocatedStatus -- detailed resize status reporting
  • SELinuxMount improvements
  • NodeInclusionPolicyInPodTopologySpread -- topology spread の node inclusion control

Key Alpha Features

  • PodLevelInPlaceScaling -- container level だけでなく pod level(aggregate)で resize
  • LeaderMigration -- controller-manager leader election を migrate
  • SchedulerQueueingHints improvements
  • RecoverVolumeExpansionFailure -- failed volume expansion から recover

4.8 Kubernetes 1.36 "ハル (Haru)" (April 2026)

Theme: 日本語の「春」(ハル/Haru)にちなんだ名称で、新しい始まりと成長を象徴しています。

Release Stats: 68 enhancements -- 18 Stable, 25 Beta, 25 Alpha。主要 theme には security hardening、AI/ML workload support、API extensibility が含まれます。EKS は GovCloud (US) を含む利用可能なすべての region で 1.36 を support しています。

Overview of Key Features:

FeatureStageKey Value
Mutating Admission PoliciesGAwebhook server を排除 -- operational simplicity, performance, availability
In-Place Pod Vertical ScalingEnhancedzero-downtime resource adjustment -- cost efficiency, SLA protection
User NamespacesGAcontainer root ≠ node root -- privilege isolation
Fine-Grained Kubelet API AuthorizationGAleast-privilege kubelet API access
Legacy ServiceAccount Token CleanupGAunused token の auto-cleanup -- attack surface reduction
Resource Health Status (DRA)ImprovedGPU device health -- failure root-cause identification の高速化

Key Graduated Features (GA)

Mutating Admission Policies (GA)

Mutating Admission Policies (MAP) は CEL-based mutation を native Kubernetes object にもたらし、external webhook server を不要にします。MAP では、mutation logic は MutatingAdmissionPolicyMutatingAdmissionPolicyBinding resources を使って declarative に定義され、API server によって in-process で評価されます。

主な特徴:

  • In-process API server evaluation: webhook network round-trip や external server latency はありません。Mutation は API server process 内で実行されます。
  • Operational simplicity: certificate management、high-availability deployment、webhook server の scaling concern は不要です。API server がすべて処理します。
  • Idempotency guaranteed: CEL expression は deterministic result を生成し、ordering や re-invocation の edge case を排除します。
  • Limitation: external data lookup(例: OPA server や image registry への問い合わせ)を必要とする mutation には、引き続き traditional webhook が必要です。MAP は self-contained で policy-driven な mutation 向けです。

Impact: admission control の webhook server は、歴史的に Kubernetes cluster における single point of failure でした。misconfigured または unavailable な webhook は、cluster 全体の pod creation を block する可能性があります。MAP は、大半の mutation use case についてこの class の operational risk を排除します。

以下の例は、in-place resize 用に annotation された pod に resizePolicy を自動注入する MutatingAdmissionPolicy を示します。これは MAP(1.36 で GA)と In-Place Pod Vertical Scaling(1.35 で GA)を組み合わせた実践的な pattern です。

yaml
apiVersion: admissionregistration.k8s.io/v1
kind: MutatingAdmissionPolicy
metadata:
  name: inject-resizepolicy
spec:
  failurePolicy: Fail
  reinvocationPolicy: Never
  matchConstraints:
    resourceRules:
      - apiGroups: [""]
        apiVersions: ["v1"]
        operations: ["CREATE"]
        resources: ["pods"]
  matchConditions:
    - name: only-resize-enabled
      expression: >-
        has(object.metadata.annotations) &&
        ("resize.example.com/enabled" in object.metadata.annotations) &&
        object.metadata.annotations["resize.example.com/enabled"] == "true"
  mutations:
    - patchType: JSONPatch
      jsonPatch:
        expression: >-
          object.spec.containers.map(c, JSONPatch{
            op: "add",
            path: "/spec/containers/" + string(object.spec.containers.indexOf(c)) + "/resizePolicy",
            value: [
              {"resourceName": "cpu",    "restartPolicy": "NotRequired"},
              {"resourceName": "memory", "restartPolicy": "RestartContainer"}
            ]
          })
---
apiVersion: admissionregistration.k8s.io/v1
kind: MutatingAdmissionPolicyBinding
metadata:
  name: inject-resizepolicy-binding
spec:
  policyName: inject-resizepolicy
  matchResources:
    namespaceSelector:
      matchLabels:
        map-demo: "true"

Safety Note: MAP matchConstraints は default で cluster-wide です。cluster 全体への意図しない modification を防ぐため、binding で必ず namespaceSelector を使って mutation scope を限定してください。

Technical Note: resizePolicy は Kubernetes API schema で atomic list として定義されています。つまり、上記のように JSONPatch を使用する必要があります。ApplyConfiguration を使おうとすると "may not mutate atomic arrays" で失敗します。

In-Place Pod Vertical Scaling Enhancements

1.35 での per-container in-place resize の GA graduation を基盤として、Kubernetes 1.36 は複数の enhancement を追加します。

  • Pod-level shared budget resize: Pod-level resources を pod restart なしで resize でき、pod 内のすべての container にまたがる aggregate resource adjustment が可能になります。
  • CPUManager checkpoint tracking: CPUManager は live resize operation 中の checkpoint state を追跡し、performance-sensitive workload の NUMA alignment を維持します。
  • CPU resize (NotRequired): restartPolicy: NotRequired の CPU change は cgroup update で適用され、zero downtime です。container restart も connection drop もありません。
  • Memory shrink behavior: Memory shrink operation は、resize 時点の actual memory usage によって RestartContainer を trigger する場合があります。production で memory resize を有効にする前に per-workload validation が不可欠です。

User Namespaces (Feature Gate Removed)

User Namespaces は 1.36 で feature gate が削除され、full production readiness に到達しました。Container UID 0(container 内の root)は unprivileged host UID に map され、application change なしで privilege isolation を提供します。

Gate が削除されたため、user namespaces は feature gate configuration なしで 1.36 を実行するすべての cluster で利用できます。これにより、container-to-host privilege isolation を実現するための third-party solution は不要になります。

KYAML (GA)

KYAML は GA に到達し、より安全な YAML subset がすべての Kubernetes manifest の standard になりました。KYAML validation は dangerous YAML pattern を default で reject します(warning だけではありません)。

YAML FeatureAllowed in KYAML?Reason
Anchors & AliasesNoInjection risk, confusion
Merge Keys (<<)NoUnpredictable behavior
Implicit booleans (yes/no)NoType coercion bugs
Non-string map keysNoAmbiguity
Duplicate keysNoSilent override
CommentsYesdocumentation に不可欠
Multi-line strings (`, >`)Yes
Flow sequences/mappingsYesStandard YAML usage
bash
# KYAML is now enforced by default
$ kubectl apply -f bad-manifest.yaml
Error from server: error parsing bad-manifest.yaml: KYAML validation failed:
  line 5: YAML anchors are not permitted
  line 12: implicit boolean value "yes" is not permitted; use "true" or "false"

Gang Scheduling (GA)

Atomic pod group scheduling が GA に昇格しました。

yaml
# GA-level gang scheduling
apiVersion: scheduling.k8s.io/v1
kind: PodGroup
metadata:
  name: mpi-job
spec:
  minMember: 8
  scheduleTimeoutSeconds: 600
  priorityClassName: high-priority

Other GA Features in 1.36:

  • AnonymousAuthConfigurableEndpoints -- endpoint ごとの anonymous auth control
  • SELinuxMount -- volume 向け SELinux label management
  • NodeInclusionPolicyInPodTopologySpread -- topology spread node inclusion
  • RecoverVolumeExpansionFailure -- failed expansion からの automated recovery
  • FineGrainedKubeletAPIAuthorization -- least-privilege kubelet API access。どの node がどの kubelet endpoint に access できるかを制限
  • LegacyServiceAccountTokenCleanUp -- unused Secret-based ServiceAccount token の auto-cleanup。long-lived credential による attack surface を削減

Phase-Aware Resource Management Pattern

この section では、In-Place Pod Vertical Scaling(1.35 で GA)と Mutating Admission Policies(1.36 で GA)を組み合わせて、phase-aware resource management を実装する実践的 pattern を示します。application lifecycle phase に基づき container resources を自動調整します。

Problem Definition

多くの containerized workloads には、異なる resource profile を必要とする明確な lifecycle phase があります。

  • Startup (warmup) phase: JVM JIT compilation、LLM model loading、index/cache prefill に高い CPU が必要
  • Steady-state (serving) phase: 通常の request handling には低い CPU で十分

どちらの phase でも Kubernetes では container は Running と表示されます。application が warmup から serving に遷移したときに resources を自動切り替えする native mechanism はありません。典型的な workaround は startup phase 向けの over-provisioning ですが、より長い steady-state phase では resource が無駄になります。

Target workloads には、JIT warmup を伴う JVM applications、model を memory に load する ML inference servers、startup 時に cache や index を build する services が含まれます。

Flow:

Pod Create (startup: large CPU, req==limit -> Guaranteed QoS)
  -> Controller watches pod.status.containerStatuses[].started
  -> started:true detected (= startup probe passed)
  -> Resize via pods/resize subresource to steady-state CPU (zero-downtime)

Key Insight -- QoS Preservation

QoS class は Pod creation time に決定され、resize しても変わりません (KEP-1287)。startup phase と steady-state phase の両方で requests == limits を設定することで、pod は lifecycle 全体を通じて Guaranteed QoS を維持します。Memory は固定(restart risk を避ける)し、CPU のみを変更します。

Annotation-Based Approach (No CRD Required)

Custom Resource を定義する代わりに、この pattern は既存 workload の annotation を使用します。lightweight controller が pod を watch し、annotation に基づいて動作します。

yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: phase-aware-app
spec:
  replicas: 2
  selector:
    matchLabels:
      app: phase-aware-app
  template:
    metadata:
      annotations:
        resize.example.com/enabled:          "true"
        resize.example.com/trigger:          "StartupProbePassed"
        resize.example.com/steady-resources: |
          {"app":{"requests":{"cpu":"50m"},"limits":{"cpu":"50m"}}}
      labels:
        app: phase-aware-app
    spec:
      containers:
        - name: app
          image: myapp:latest
          resizePolicy:
            - resourceName: cpu
              restartPolicy: NotRequired
            - resourceName: memory
              restartPolicy: RestartContainer
          resources:
            requests:
              cpu: "200m"
              memory: 64Mi
            limits:
              cpu: "200m"
              memory: 64Mi
          startupProbe:
            httpGet:
              path: /healthz
              port: 8080
            initialDelaySeconds: 5
            periodSeconds: 3
            failureThreshold: 30

Controller Implementation (Go)

以下の controller は annotated pods を watch し、startup probe が pass したときに steady-state resources へ patch します。Pods のみを watch するため、Deployments、StatefulSets、DaemonSets、Argo Rollouts で同一に動作し、workload-type branching は不要です。

go
// pod-resizer — annotation-based zero-downtime in-place downscale controller.
// Watches Pods only — works identically for Deployment/StatefulSet/DaemonSet/Rollout.
// On startup probe pass, patches to steady resources via pods/resize subresource.
// Maintains req==limit on both phases to preserve Guaranteed QoS (KEP-1287).
package main

import (
	"context"
	"encoding/json"
	"fmt"
	"log"
	"strconv"
	"sync"
	"time"

	corev1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/client-go/informers"
	"k8s.io/client-go/kubernetes"
	"k8s.io/client-go/rest"
	"k8s.io/client-go/tools/cache"
)

const (
	annEnabled = "resize.example.com/enabled"
	annTrigger = "resize.example.com/trigger"
	annDelay   = "resize.example.com/delay-seconds"
	annSteady  = "resize.example.com/steady-resources"
	annResized = "resize.example.com/resized"
)

type resVals struct {
	Requests map[string]string `json:"requests,omitempty"`
	Limits   map[string]string `json:"limits,omitempty"`
}

var clientset *kubernetes.Clientset
var processed sync.Map

func main() {
	cfg, err := rest.InClusterConfig()
	if err != nil {
		log.Fatalf("in-cluster config: %v", err)
	}
	clientset, err = kubernetes.NewForConfig(cfg)
	if err != nil {
		log.Fatalf("clientset: %v", err)
	}

	factory := informers.NewSharedInformerFactory(clientset, 15*time.Second)
	podInformer := factory.Core().V1().Pods().Informer()
	podInformer.AddEventHandler(cache.ResourceEventHandlerFuncs{
		AddFunc:    func(obj interface{}) { handle(obj) },
		UpdateFunc: func(_, obj interface{}) { handle(obj) },
	})

	stop := make(chan struct{})
	defer close(stop)
	log.Printf("pod-resizer starting; watching pods annotated %s=true", annEnabled)
	factory.Start(stop)
	factory.WaitForCacheSync(stop)
	log.Printf("informer cache synced; ready")
	select {}
}

func handle(obj interface{}) {
	pod, ok := obj.(*corev1.Pod)
	if !ok {
		return
	}
	a := pod.Annotations
	if a == nil || a[annEnabled] != "true" || a[annResized] == "true" {
		return
	}
	if pod.DeletionTimestamp != nil || pod.Status.Phase != corev1.PodRunning {
		return
	}

	trigger := a[annTrigger]
	if trigger == "" {
		trigger = "StartupProbePassed"
	}
	if !triggerMet(pod, trigger, a[annDelay]) {
		return
	}

	steady := map[string]resVals{}
	if err := json.Unmarshal([]byte(a[annSteady]), &steady); err != nil {
		log.Printf("ERROR %s/%s: bad %s: %v", pod.Namespace, pod.Name, annSteady, err)
		return
	}
	patch := buildResizePatch(steady)
	if patch == nil {
		return
	}
	pb, _ := json.Marshal(patch)

	key := string(pod.UID)
	if _, loaded := processed.LoadOrStore(key, true); loaded {
		return
	}

	if _, err := clientset.CoreV1().Pods(pod.Namespace).Patch(
		context.TODO(), pod.Name, types.StrategicMergePatchType, pb,
		metav1.PatchOptions{}, "resize"); err != nil {
		processed.Delete(key)
		log.Printf("ERROR %s/%s: resize patch failed: %v", pod.Namespace, pod.Name, err)
		return
	}
	log.Printf("RESIZED %s/%s [%s] trigger=%s patch=%s",
		pod.Namespace, pod.Name, ownerKind(pod), trigger, string(pb))

	mark := []byte(fmt.Sprintf(`{"metadata":{"annotations":{%q:"true"}}}`, annResized))
	if _, err := clientset.CoreV1().Pods(pod.Namespace).Patch(
		context.TODO(), pod.Name, types.MergePatchType, mark, metav1.PatchOptions{}); err != nil {
		log.Printf("WARN %s/%s: marker patch failed: %v", pod.Namespace, pod.Name, err)
	}
}

func triggerMet(pod *corev1.Pod, trigger, delayStr string) bool {
	switch trigger {
	case "Ready":
		for _, c := range pod.Status.Conditions {
			if c.Type == corev1.PodReady {
				return c.Status == corev1.ConditionTrue
			}
		}
		return false
	case "Delay":
		delay, _ := strconv.Atoi(delayStr)
		for _, cs := range pod.Status.ContainerStatuses {
			if cs.State.Running != nil {
				return time.Since(cs.State.Running.StartedAt.Time) >= time.Duration(delay)*time.Second
			}
		}
		return false
	default:
		if len(pod.Status.ContainerStatuses) == 0 {
			return false
		}
		for _, cs := range pod.Status.ContainerStatuses {
			if cs.Started == nil || !*cs.Started {
				return false
			}
		}
		return true
	}
}

func buildResizePatch(steady map[string]resVals) map[string]interface{} {
	var containers []map[string]interface{}
	for name, rv := range steady {
		res := map[string]interface{}{}
		if len(rv.Requests) > 0 {
			res["requests"] = rv.Requests
		}
		if len(rv.Limits) > 0 {
			res["limits"] = rv.Limits
		}
		containers = append(containers, map[string]interface{}{"name": name, "resources": res})
	}
	if len(containers) == 0 {
		return nil
	}
	return map[string]interface{}{"spec": map[string]interface{}{"containers": containers}}
}

func ownerKind(pod *corev1.Pod) string {
	if len(pod.OwnerReferences) > 0 {
		return pod.OwnerReferences[0].Kind
	}
	return "Pod"
}

Controller RBAC

Controller は patching のために pods/resize subresource への access と、standard pod watch/list permission を必要とします。

yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  name: pod-resizer
  namespace: pod-resizer-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: pod-resizer
rules:
  - apiGroups: [""]
    resources: ["pods"]
    verbs: ["get", "list", "watch", "patch"]
  - apiGroups: [""]
    resources: ["pods/resize"]          # Required for resize subresource
    verbs: ["patch"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: pod-resizer
subjects:
  - kind: ServiceAccount
    name: pod-resizer
    namespace: pod-resizer-system
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: pod-resizer

Demo Workload

phase-aware resize pattern を test するための minimal workload です。

yaml
apiVersion: v1
kind: Namespace
metadata:
  name: resize-demo
  labels:
    map-demo: "true"        # Enables MAP resizePolicy injection
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: busybox-resize-demo
  namespace: resize-demo
spec:
  replicas: 2
  selector:
    matchLabels:
      app: busybox-resize-demo
  template:
    metadata:
      labels:
        app: busybox-resize-demo
      annotations:
        resize.example.com/enabled:          "true"
        resize.example.com/trigger:          "StartupProbePassed"
        resize.example.com/steady-resources: |
          {"busybox":{"requests":{"cpu":"50m"},"limits":{"cpu":"50m"}}}
    spec:
      containers:
        - name: busybox
          image: busybox:1.36
          command: ["sh", "-c", "echo 'starting warmup'; sleep 10; echo 'ready'; while true; do sleep 3600; done"]
          resources:
            requests:
              cpu: "200m"
              memory: 64Mi
            limits:
              cpu: "200m"
              memory: 64Mi
          startupProbe:
            exec:
              command: ["sh", "-c", "test -f /tmp/ready || (sleep 8 && touch /tmp/ready)"]
            initialDelaySeconds: 2
            periodSeconds: 3
            failureThreshold: 10

Argo Rollouts Compatibility

Controller は modification なしで Argo Rollouts と動作します。ownership chain は Rollout -> ReplicaSet -> Pod であり、Deployment -> ReplicaSet -> Pod と同一の構造です。Controller は Pods のみを watch し、type-specific logic のために owner reference を inspect しないため、適切な annotation を持つ pod を作成する任意の workload controller が support されます。

Test Results (EKS 1.36.1)

EKS v1.36.1、containerd 2.2.3、Amazon Linux 2023 (cgroup v2, arm64/Graviton) で test 済みです。

Controller log output:

2026/06/28 09:12:03 pod-resizer starting; watching pods annotated resize.example.com/enabled=true
2026/06/28 09:12:03 informer cache synced; ready
2026/06/28 09:12:41 RESIZED resize-demo/busybox-resize-demo-7f8b9c6d4-k2xnm [ReplicaSet] trigger=StartupProbePassed patch={"spec":{"containers":[{"name":"busybox","resources":{"limits":{"cpu":"50m"},"requests":{"cpu":"50m"}}}]}}
2026/06/28 09:12:41 RESIZED resize-demo/busybox-resize-demo-7f8b9c6d4-p9wvj [ReplicaSet] trigger=StartupProbePassed patch={"spec":{"containers":[{"name":"busybox","resources":{"limits":{"cpu":"50m"},"requests":{"cpu":"50m"}}}]}}
2026/06/28 09:13:05 RESIZED resize-demo/busybox-resize-ds-xq7zt [DaemonSet] trigger=StartupProbePassed patch={"spec":{"containers":[{"name":"busybox","resources":{"limits":{"cpu":"50m"},"requests":{"cpu":"50m"}}}]}}
2026/06/28 09:13:22 RESIZED resize-demo/busybox-resize-sts-0 [StatefulSet] trigger=StartupProbePassed patch={"spec":{"containers":[{"name":"busybox","resources":{"limits":{"cpu":"50m"},"requests":{"cpu":"50m"}}}]}}

In-place resize verification:

WorkloadQoSCPU (req/lim)restartCountcontainerID
Deployment (x2)Guaranteed -> Guaranteed200m -> 50m0 -> 0Identical
DaemonSetGuaranteed -> Guaranteed200m -> 50m0 -> 0Identical
StatefulSetGuaranteed -> Guaranteed200m -> 50m0 -> 0Identical

Key Evidence: restartCount=0 かつ resize 前後で containerID が同一であることにより、true in-place cgroup CPU reallocation が確認されます。container は再作成されていません。QoS class は resize 全体を通じて Guaranteed として維持されました。

MAP Injection Test Results

MutatingAdmissionPolicy が annotation presence に基づいて resizePolicy を正しく inject することを検証します。

CaseAnnotation PresentInjected resizePolicyVerdict
with-annotationYes[{cpu:NotRequired},{memory:RestartContainer}]Injected (no webhook needed)
without-annotationNo[] (none)Not injected (matchCondition working)

Advantages of the Annotation-Based Approach

AspectBenefit
Operational overheadCRD/CR なし -- 既存 workload に annotation を追加するだけ
Workload universalityController は Pods のみを watch -- Deployment/StatefulSet/DaemonSet/Rollout で同一 behavior
Code complexitytype branching、child creation、owner-reference handling なし
Existing workloadsannotation patch で適用(manifest rewrite 不要)
resizePolicy automationMAP (GA) が pod creation 時に自動注入 -- webhook なしで fully automated

Caveats

  • CPU-only zero-downtime resize は安全で検証済みです。Memory shrink は actual usage によって container restart を trigger する場合があります。本番有効化前に workload ごとに validate してください。
  • --subresource resize には kubectl version 1.32 以降が必要です(debugging のみ。controller は subresources を native に扱う client-go を使用します)。
  • HPA および CPUManager static NUMA alignment policy との interaction は workload ごとの validation が必要です。Concurrent HPA scaling と in-place resize は conflicting resource target を生む可能性があります。
  • production deployment では、multi-replica high availability のために controller に leader election を追加してください。

Upgrade Checklist

  • Ingress-NGINX retired (2026-03-24): Security patch は停止しています。Gateway API compatible controller(例: Envoy Gateway, Istio Gateway, Cilium Gateway API)へ migrate してください。
  • IPVS mode / externalIPs service audit: 1.36 networking change との compatibility のため、IPVS mode または externalIPs を使用する services を review してください。upgrade 前の audit が推奨されます。
  • EKS Cluster Insights: upgrade 開始前に EKS Cluster Insights を実行し、deprecated API usage、incompatible add-on versions、その他 compatibility issue を特定してください。

Key Beta Features

Pod-Level In-Place Scaling (Beta)

1.35 での per-container in-place resize の GA を基盤として、pod-level in-place scaling は pod level で aggregate resource limit を設定し、それを resize できるようにします。

yaml
apiVersion: v1
kind: Pod
metadata:
  name: multi-container-app
spec:
  resources:                          # Pod-level resource limits
    limits:
      cpu: "4"
      memory: 8Gi
    requests:
      cpu: "2"
      memory: 4Gi
  containers:
    - name: app
      image: myapp:latest
      resources:
        requests:
          cpu: "1"
          memory: 2Gi
    - name: sidecar
      image: sidecar:latest
      resources:
        requests:
          cpu: 500m
          memory: 512Mi
    # Remaining resources available for burst

Improved DRA Partitioning

GPU のような device 向け DRA partitioning が beta に到達し、fine-grained resource sharing が可能になりました。

yaml
# Request a GPU partition (MIG-like)
apiVersion: resource.k8s.io/v1
kind: ResourceClaim
metadata:
  name: gpu-partition
spec:
  devices:
    requests:
      - name: gpu-slice
        deviceClassName: gpu-partition
        selectors:
          - cel:
              expression: >-
                device.capacity["gpu.nvidia.com"].memory.compareTo(quantity("10Gi")) >= 0

Key Alpha Features

  • MultipleSCTPAssociations -- pod ごとの multiple SCTP associations
  • SchedulerFIFO -- FIFO scheduling queue option
  • CPUManagerPolicyAlpha enhancements

5. Key Feature Graduation Timeline

以下の table は、major feature graduation の comprehensive cross-version view を提供します。採用を計画している feature の full lifecycle を理解するために使用してください。

Core Features

FeatureKEPAlphaBetaGADescription
Sidecar ContainersKEP-7531.281.29/1.311.33restartPolicy: Always を持つ init containers による native sidecar support
In-Place Pod Vertical ScalingKEP-12871.271.331.35restart なしで pod CPU/memory を resize
Pod Scheduling ReadinessKEP-35211.261.271.30pod scheduling を遅延させる scheduling gates
Job Success PolicyKEP-39981.281.311.33Jobs 向け custom success criteria
Pod-Level ResourcesKEP-28371.321.331.34pod level の aggregate resource limits

Security Features

FeatureKEPAlphaBetaGADescription
ValidatingAdmissionPolicy (CEL)KEP-34881.261.281.30CEL による native admission control
MutatingAdmissionPolicy (CEL)KEP-39621.331.34/1.351.36CEL による native mutation
StructuredAuthorizationConfigurationKEP-32211.291.301.32ordered authorization chain configuration
AppArmor GAKEP-241.41.281.31native AppArmor profile API field
User NamespacesKEP-1271.251.30/1.331.34security isolation 用 UID/GID remapping
KYAMLKEP-42221.331.34/1.351.36Kubernetes manifest 向けの safer YAML subset

Networking Features

FeatureKEPAlphaBetaGADescription
Gateway API (CRD)KEP-18971.181.221.26+next-gen Ingress API (CRD-based, version independent)
ServiceCIDR / IPAddress APIKEP-18801.271.311.33dynamic Service IP range management
Topology Aware RoutingKEP-24331.211.231.33zone-aware traffic routing
nftables kube-proxyKEP-38661.291.311.34nftables-based Service routing
Traffic DistributionKEP-44441.301.311.34Service traffic distribution preferences

Storage Features

FeatureKEPAlphaBetaGADescription
ReadWriteOncePodKEP-24851.221.271.29single-pod RW access mode
VolumeAttributesClassKEP-37511.291.311.34mutable volume attributes (IOPS, throughput)
PV Last Phase TransitionKEP-37621.281.291.31PV phase change の timestamp tracking
RecoverVolumeExpansionFailureKEP-17901.231.351.36failed volume expansion からの recovery

Scheduling Features

FeatureKEPAlphaBetaGADescription
Gang SchedulingKEP-48181.351.351.36distributed workloads 向け atomic group scheduling
Pod Scheduling ReadinessKEP-35211.261.271.30deferred scheduling 用 scheduling gates
MinDomainsInPodTopologySpreadKEP-30221.241.251.30topology spread の minimum domain count

Resource Management Features

FeatureKEPAlphaBetaGADescription
DRA Core APIsKEP-30631.261.311.34accelerator 向け Dynamic Resource Allocation
HPA Container MetricsKEP-22731.201.271.30per-container HPA metrics
OCI Images as VolumesKEP-46391.311.331.34OCI image を read-only volume として mount

Comprehensive Timeline Visualization


6. Deprecations and Removals

deprecation と removal を理解することは upgrade planning に不可欠です。Deprecation は、API または feature が将来の version で removed されることを知らせ、team に migration の時間を与えます。Removal は API または feature の実際の削除です。

Kubernetes API Deprecation Policy

  • GA APIs: replacement GA API が利用可能な場合にのみ deprecated になります。removal まで最低 12 か月または 3 release。
  • Beta APIs: deprecation 後、removal まで最低 9 か月または 3 release。
  • Alpha APIs: notice なしで任意の release で removed される可能性があります。

API Deprecations and Removals by Version

Removed in 1.29

API/FeatureReplaced ByMigration Path
SecurityContextDeny admission pluginPod Security Standards (PSS)PodSecurity admission controller へ migrate

Removed in 1.32

API/FeatureReplaced ByMigration Path
flowcontrol.apiserver.k8s.io/v1beta2flowcontrol.apiserver.k8s.io/v1beta3 -> v1FlowSchema と PriorityLevelConfiguration resource の API version を update
autoscaling/v2beta1 HPA APIautoscaling/v2すべての HPA manifest を autoscaling/v2 に update

Removed in 1.34

API/FeatureReplaced ByMigration Path
Legacy --authorization-mode flag patternsStructuredAuthorizationConfigurationstructured authorization config file へ migrate
flowcontrol.apiserver.k8s.io/v1beta3flowcontrol.apiserver.k8s.io/v1stable API version に update

Deprecated (Not Yet Removed)

API/FeatureDeprecated InExpected RemovalMigration Path
In-tree cloud provider (AWS, GCP, Azure)1.26+Ongoingexternal cloud controller manager へ migrate
Annotation-based AppArmor profiles1.311.35securityContext.appArmorProfile field を使用
batch/v1beta1 CronJob1.211.25 (removed)batch/v1 を使用
policy/v1beta1 PodDisruptionBudget1.211.25 (removed)policy/v1 を使用
kube-proxy iptables mode1.33 (soft)TBDnftables または IPVS への migration を計画

Removed Feature Gates by Version

Feature が GA に到達すると、通常その feature gate は 2 release 後に removed されます。これは GA feature を disable できないことを意味します。

bash
# Check for feature gates that reference removed gates
# This would cause kubelet startup failure after upgrade

# Feature gates removed in 1.33:
# - SidecarContainers (GA in 1.33, gate removed in 1.35)
# - ServiceCIDR (GA in 1.33, gate removed in 1.35)

# Feature gates removed in 1.34:
# - UserNamespacesSupport (GA in 1.34, gate removed in 1.36)
# - VolumeAttributesClass (GA in 1.34, gate removed in 1.36)

# If you have explicit feature gate overrides, check them:
kubectl get cm kubelet-config -n kube-system -o yaml | grep featureGates -A 20

Migration Checklist for Deprecated APIs

bash
#!/bin/bash
# deprecation-check.sh - Check for deprecated API usage

echo "=== Kubernetes Deprecation Audit ==="

# Check for deprecated API versions in cluster resources
echo ""
echo "--- Checking for deprecated APIs in running resources ---"

# FlowSchema (v1beta2/v1beta3 deprecated)
echo "FlowSchemas using deprecated API versions:"
kubectl get flowschemas -o json | jq -r '.items[] | select(.apiVersion != "flowcontrol.apiserver.k8s.io/v1") | "\(.metadata.name): \(.apiVersion)"'

# Check for AppArmor annotations (deprecated in 1.31)
echo ""
echo "Pods using deprecated AppArmor annotations:"
kubectl get pods -A -o json | jq -r '.items[] | select(.metadata.annotations // {} | keys[] | test("apparmor.security.beta")) | "\(.metadata.namespace)/\(.metadata.name)"'

# Check for deprecated admission webhooks
echo ""
echo "Admission webhooks using deprecated API versions:"
kubectl get validatingwebhookconfigurations -o json | jq -r '.items[] | select(.apiVersion | test("v1beta1")) | .metadata.name'
kubectl get mutatingwebhookconfigurations -o json | jq -r '.items[] | select(.apiVersion | test("v1beta1")) | .metadata.name'

# Check Helm releases for deprecated APIs
echo ""
echo "Checking Helm releases for deprecated API versions:"
for release in $(helm list -A -q); do
  helm get manifest $release -n $(helm list -A -f "^${release}$" -o json | jq -r '.[0].namespace') 2>/dev/null | \
    grep "apiVersion:" | sort -u | while read line; do
      case "$line" in
        *v1beta1*|*v1beta2*|*v2beta1*)
          echo "  $release: $line (DEPRECATED)"
          ;;
      esac
    done
done

echo ""
echo "=== Audit Complete ==="

API Compatibility Matrix

upgrade 前に manifest が target Kubernetes version と compatible であることを verify するため、この table を使用してください。

ResourceStable APIDeprecated APIsSafe Since
HorizontalPodAutoscalerautoscaling/v2v2beta1 (removed 1.26), v2beta2 (removed 1.26)1.23
CronJobbatch/v1v1beta1 (removed 1.25)1.21
PodDisruptionBudgetpolicy/v1v1beta1 (removed 1.25)1.21
CSIDriverstorage.k8s.io/v1v1beta1 (removed 1.22)1.18
FlowSchemaflowcontrol.apiserver.k8s.io/v1v1beta2 (removed 1.32), v1beta3 (removed 1.34)1.29
ValidatingAdmissionPolicyadmissionregistration.k8s.io/v1v1beta1 (deprecated 1.30)1.30
ResourceClaim (DRA)resource.k8s.io/v1v1alpha3 (removed 1.34), v1beta1 (removed 1.34)1.34
VolumeAttributesClassstorage.k8s.io/v1v1beta1 (removed 1.36)1.34

7. EKS-Specific Considerations

EKS Version Lag vs. Upstream

EKS release は upstream Kubernetes から約 2〜4 か月遅れます。この lag には以下の利点があります。

BenefitDescription
StabilityAWS が EKS-specific integration とともに release を validate
Add-on CompatibilityManaged add-ons が test および update される
AMI AvailabilityOptimized EKS AMIs が build および test される
Security Patchesknown CVE が release 前に対処される

EKS Feature Gate Availability

すべての upstream Kubernetes feature gate が EKS で利用できるわけではありません。AWS が control plane configuration を管理するため、以下のようになります。

  • GA features: 常に enabled(upstream と同じ)
  • Beta features (enabled by default): 一般に EKS で利用可能
  • Beta features (disabled by default): EKS support ticket が必要、または利用不可の場合あり
  • Alpha features: EKS では利用不可(alpha features は EKS で決して enabled になりません)
bash
# Check which feature gates are active on your EKS cluster's nodes
kubectl get --raw "/api/v1/nodes/$(kubectl get nodes -o jsonpath='{.items[0].metadata.name}')/proxy/configz" | \
  jq '.kubeletconfig.featureGates'

# Check API server feature gates via metrics
kubectl get --raw /metrics 2>/dev/null | grep kubernetes_feature_enabled | head -30

EKS Managed Add-on Compatibility Matrix

EKS cluster を upgrade する際、add-on compatibility は重要です。各 Kubernetes version には特定の add-on version requirement があります。

Add-onK8s 1.31K8s 1.32K8s 1.33K8s 1.34K8s 1.35K8s 1.36
VPC CNIv1.18+v1.19+v1.19+v1.20+v1.20+v1.21+
CoreDNSv1.11.1+v1.11.3+v1.12.0+v1.12.0+v1.12.1+v1.12.1+
kube-proxyv1.31.xv1.32.xv1.33.xv1.34.xv1.35.xv1.36.x
EBS CSIv1.35+v1.36+v1.37+v1.38+v1.39+v1.40+
EFS CSIv2.0+v2.1+v2.1+v2.2+v2.2+v2.3+
ADOTv0.102+v0.104+v0.106+v0.108+v0.110+v0.112+

Note: specific patch version が必要な場合があるため、upgrade 前には必ず最新の EKS add-on version compatibility を確認してください。

bash
# Check current add-on versions
aws eks describe-addon-versions --kubernetes-version 1.36 \
  --addon-name vpc-cni --query 'addons[].addonVersions[].addonVersion' --output table

# List all installed add-ons and their versions
aws eks list-addons --cluster-name my-cluster --output table
for addon in $(aws eks list-addons --cluster-name my-cluster --query 'addons[]' --output text); do
  version=$(aws eks describe-addon --cluster-name my-cluster --addon-name $addon \
    --query 'addon.addonVersion' --output text)
  echo "$addon: $version"
done

EKS Auto Mode Version Support

EKS Auto Mode は node group を自動管理して cluster management を簡素化しますが、独自の version consideration があります。

FeatureBehavior with Auto Mode
Control plane upgradesEKS により managed(API/console 経由で trigger 可能)
Node upgradesAuto Mode により automatically handled
Version skewAuto Mode は control plane と nodes の間で n-1 skew を維持
Add-on updatesCore add-ons は automatically managed
Feature gatesNode-level feature gates は Auto Mode により managed
bash
# Check Auto Mode status
aws eks describe-cluster --name my-cluster \
  --query 'cluster.computeConfig' --output json

# Verify Auto Mode node version alignment
kubectl get nodes -o custom-columns=\
NAME:.metadata.name,\
VERSION:.status.nodeInfo.kubeletVersion,\
INSTANCE_TYPE:.metadata.labels.'node\.kubernetes\.io/instance-type'

Important: EKS Auto Mode を使用する場合、custom NodePool configuration が target Kubernetes version と compatible であることを確認してください。Auto Mode NodePools は upgrade 中に new AMI を自動採用しますが、custom configuration は manual verification が必要な場合があります。

Extended Support Cost Analysis

extended support の financial impact を理解することで、team は upgrade planning の優先順位を付けやすくなります。

Cost Comparison: Standard vs Extended Support (per cluster)

Standard Support:  $0.10/hour  x  24 hours  x  365 days  =  $876/year
Extended Support:  $0.60/hour  x  24 hours  x  365 days  =  $5,256/year

Additional cost per cluster in extended support:  $4,380/year
Clusters in Extended SupportAdditional Annual Cost
1 cluster$4,380
5 clusters$21,900
10 clusters$43,800
25 clusters$109,500
50 clusters$219,000
100 clusters$438,000

8. Version Upgrade Planning

Feature Gate Testing Strategy

upgrade 前に、staging environment で新しい feature gate を test し、compatibility を確認してください。

yaml
# Step 1: Enable feature gates in staging
# For EKS managed node groups, use a custom launch template
apiVersion: eksctl.io/v1alpha5
kind: ClusterConfig
metadata:
  name: staging-cluster
  region: us-west-2
managedNodeGroups:
  - name: test-nodes
    instanceType: m6i.xlarge
    desiredCapacity: 3
    kubelet:
      featureGates:
        InPlacePodVerticalScaling: true
        UserNamespacesSupport: true
bash
# Step 2: Verify feature gates are active
kubectl get --raw "/api/v1/nodes/$(kubectl get nodes -o jsonpath='{.items[0].metadata.name}')/proxy/configz" | \
  jq '.kubeletconfig.featureGates'

# Step 3: Run feature-specific tests
# Example: Test in-place pod resize
cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: Pod
metadata:
  name: resize-test
spec:
  containers:
    - name: test
      image: nginx:latest
      resources:
        requests:
          cpu: 100m
          memory: 128Mi
        limits:
          cpu: 200m
          memory: 256Mi
      resizePolicy:
        - resourceName: cpu
          restartPolicy: NotRequired
        - resourceName: memory
          restartPolicy: NotRequired
EOF

# Attempt resize
kubectl patch pod resize-test --subresource resize --patch '{
  "spec": {"containers": [{"name": "test", "resources": {"requests": {"cpu": "200m"},"limits": {"cpu": "400m"}}}]}
}'

# Verify resize succeeded
kubectl get pod resize-test -o jsonpath='{.status.resize}'
kubectl get pod resize-test -o jsonpath='{.status.containerStatuses[0].allocatedResources}'

Pre-Upgrade Checklist by Version Jump

各 version upgrade を計画する際は、この checklist framework を使用してください。source version と target version に基づいて specific item を埋めます。

General Pre-Upgrade Checklist (All Versions)

markdown
## Pre-Upgrade Checklist: v1.X -> v1.Y

### Phase 1: Assessment (1-2 weeks before)
- [ ] Review Kubernetes changelog for target version
- [ ] Review EKS release notes for target version
- [ ] Check deprecated API usage with `kubectl convert` or Pluto
- [ ] Verify add-on compatibility matrix
- [ ] Check third-party operator compatibility (cert-manager, Istio, ArgoCD, etc.)
- [ ] Review feature gate changes (new, graduated, removed)
- [ ] Test upgrade in staging/dev environment

### Phase 2: Preparation (1 week before)
- [ ] Back up etcd (EKS manages this, but verify backup schedule)
- [ ] Document current cluster state (versions, add-ons, node groups)
- [ ] Update IaC templates (Terraform, CDK, CloudFormation)
- [ ] Prepare rollback plan
- [ ] Schedule maintenance window
- [ ] Notify stakeholders

### Phase 3: Execution
- [ ] Upgrade control plane
- [ ] Verify API server health
- [ ] Upgrade managed add-ons (CoreDNS, kube-proxy, VPC CNI)
- [ ] Upgrade EBS CSI driver
- [ ] Upgrade node groups (rolling update)
- [ ] Verify node health and version
- [ ] Run smoke tests

### Phase 4: Validation
- [ ] Verify all workloads are running
- [ ] Check HPA/VPA functionality
- [ ] Validate ingress/networking
- [ ] Test service mesh (if applicable)
- [ ] Verify monitoring and alerting
- [ ] Check storage operations (PVC create, attach, resize)
- [ ] Run integration tests

Version-Specific Upgrade Notes

Upgrading to 1.33 (from 1.32):

markdown
Additional checks:
- [ ] Sidecar containers GA: Verify init containers with restartPolicy: Always work as expected
- [ ] In-Place Pod Resize beta: Test resize behavior with existing VPA configurations
- [ ] ServiceCIDR GA: If using custom Service CIDR, verify compatibility
- [ ] Topology Aware Routing GA: Review Service traffic distribution settings

Upgrading to 1.34 (from 1.33):

markdown
Additional checks:
- [ ] DRA GA: If using device plugins, plan migration to DRA
- [ ] KYAML beta: Audit YAML manifests for anchor/alias usage
- [ ] VolumeAttributesClass GA: Test volume modification workflows
- [ ] Namespace deletion changes: Verify namespace cleanup procedures
- [ ] User Namespaces GA: Test workloads with hostUsers: false

Upgrading to 1.35 (from 1.34):

markdown
Additional checks:
- [ ] In-Place Pod Resize GA: Full production use now safe
- [ ] KYAML enabled by default: Fix any YAML warnings before upgrade
- [ ] Gang Scheduling alpha: Not available on EKS (alpha)
- [ ] Remove deprecated feature gate overrides for 1.33 GA features
- [ ] Verify sidecar container feature gate is not explicitly set (removed in 1.35)

Upgrading to 1.36 (from 1.35):

markdown
Additional checks:
- [ ] KYAML GA: All YAML must pass KYAML validation (strict enforcement)
- [ ] Gang Scheduling GA: Evaluate for distributed workloads
- [ ] Pod-level In-Place Scaling beta: Test pod-level resource limits
- [ ] Remove deprecated feature gate overrides for 1.34 GA features

API Compatibility Verification

bash
#!/bin/bash
# api-compat-check.sh - Verify API compatibility before upgrade

TARGET_VERSION=${1:-"1.36"}
echo "=== API Compatibility Check for Kubernetes $TARGET_VERSION ==="

# Tool 1: Use kubectl convert (if available)
echo ""
echo "--- Checking with kubectl convert ---"
# Install convert plugin if not present
# kubectl krew install convert

# Tool 2: Use Pluto for deprecated API detection
echo ""
echo "--- Checking with Pluto ---"
if command -v pluto &> /dev/null; then
  echo "Scanning cluster for deprecated APIs..."
  pluto detect-all-in-cluster --target-versions k8s=v${TARGET_VERSION}
  
  echo ""
  echo "Scanning Helm releases..."
  pluto detect-helm --target-versions k8s=v${TARGET_VERSION}
else
  echo "Pluto not installed. Install with:"
  echo "  brew install FairwindsOps/tap/pluto"
  echo "  or: kubectl krew install deprecations"
fi

# Tool 3: Check with kubent (kube-no-trouble)
echo ""
echo "--- Checking with kubent ---"
if command -v kubent &> /dev/null; then
  kubent --target-version ${TARGET_VERSION}
else
  echo "kubent not installed. Install from: https://github.com/doitintl/kube-no-trouble"
fi

# Manual checks
echo ""
echo "--- Manual API Version Checks ---"

# Check for v1beta1 usage
echo "Resources using v1beta1 APIs:"
kubectl api-resources -o wide 2>/dev/null | grep v1beta1

# Check CRDs for deprecated API versions
echo ""
echo "CRDs with deprecated conversion webhooks:"
kubectl get crds -o json | jq -r '.items[] | select(.spec.conversion.webhook != null) | .metadata.name'

echo ""
echo "=== Compatibility Check Complete ==="

Add-on Version Alignment

bash
#!/bin/bash
# addon-alignment.sh - Verify add-on compatibility for target K8s version

CLUSTER_NAME=${1:-"my-cluster"}
TARGET_K8S_VERSION=${2:-"1.36"}

echo "=== Add-on Alignment Check ==="
echo "Cluster: $CLUSTER_NAME"
echo "Target K8s Version: $TARGET_K8S_VERSION"
echo ""

# Get current add-on versions
echo "--- Current Add-on Versions ---"
for addon in $(aws eks list-addons --cluster-name $CLUSTER_NAME --query 'addons[]' --output text); do
  current_version=$(aws eks describe-addon --cluster-name $CLUSTER_NAME --addon-name $addon \
    --query 'addon.addonVersion' --output text 2>/dev/null)
  echo "$addon: $current_version"
done

# Get compatible versions for target
echo ""
echo "--- Compatible Versions for K8s $TARGET_K8S_VERSION ---"
for addon in vpc-cni coredns kube-proxy aws-ebs-csi-driver; do
  echo ""
  echo "$addon:"
  aws eks describe-addon-versions \
    --addon-name $addon \
    --kubernetes-version $TARGET_K8S_VERSION \
    --query 'addons[].addonVersions[?compatibilities[?defaultVersion==`true`]].addonVersion' \
    --output text 2>/dev/null | head -5
  
  default_version=$(aws eks describe-addon-versions \
    --addon-name $addon \
    --kubernetes-version $TARGET_K8S_VERSION \
    --query 'addons[].addonVersions[?compatibilities[?defaultVersion==`true`]].addonVersion | [0]' \
    --output text 2>/dev/null)
  echo "  Default: $default_version"
done

echo ""
echo "=== Alignment Check Complete ==="

Upgrade Execution Workflow

Rollback Strategy

Update (2026-07-01): Amazon EKS は Kubernetes version rollback support を announcement しました。upgrade から 7 日以内であれば、control plane を previous minor version に rollback できます。API compatibility、version skew、add-on compatibility、cluster health を対象とする automated Rollback Readiness check が最初に実行されます。EKS Auto Mode cluster は自動的に rollback され、worker nodes は自動で戻り、control plane は順番に restore されます。追加 charge はなく、すべての region で利用可能です。以下の strategy は、7 日を過ぎた場合やこの feature が利用できない場合の fallback です。(Source: Amazon EKS announces Kubernetes version rollback)

yaml
# Upgrade rollback strategy
rollback_strategy:

  control_plane:
    note: "Within 7 days: use EKS native version rollback / Beyond 7 days: blue-green cluster strategy"
    mitigation:
      - "Use EKS version rollback to restore the previous minor version immediately (within 7 days, no additional cost)"
      - "Beyond 7 days, fall back to a blue/green cluster strategy established before the upgrade"
      - "Shift traffic via Route 53 weighted routing"
      - "Migrate workloads to the new cluster"

  node_groups:
    strategy: "Create new node group + retain previous node group"
    steps:
      - "Do not immediately delete the previous version's node group"
      - "If issues arise, remove the taint from the previous node group"
      - "Add a taint to the new node group to shift traffic"

  workloads:
    strategy: "GitOps-based rollback"
    steps:
      - "Roll back to the previous commit in ArgoCD/Flux"
      - "Run a Helm rollback"

  addons:
    strategy: "Downgrade to the previous version"
    command: |
      aws eks update-addon \
        --cluster-name my-cluster \
        --addon-name vpc-cni \
        --addon-version <previous-version> \
        --resolve-conflicts OVERWRITE

9. Future Outlook

Features in Active Development

Kubernetes community は container orchestration の境界を広げ続けています。ここでは、今後の release に登場する可能性がある active development 中の key feature と trend を示します。

Near-Term (Expected 1.37 - 1.38)

FeatureCurrent StateExpected TimelineImpact
Pod-Level In-Place Scaling GABeta (1.36)1.37aggregate pod resource management
MutatingAdmissionPolicy enhancementsGA (1.36)Ongoingricher CEL mutation patterns
Improved DRA partitioningBeta (1.36)1.37fine-grained GPU sharing
Scheduler improvementsVariousOngoingbetter bin-packing, queue management

AI/ML Workload Optimization

Kubernetes は AI/ML workloads をよりよく support するため急速に進化しています。

  • DRA ecosystem growth: specialized hardware(TPU、custom ASIC など)向け device driver の増加
  • Gang scheduling maturity: strict co-scheduling requirement を持つ distributed training の support 向上
  • GPU time-slicing and MIG: GPU partitioning の native Kubernetes support
  • Network-aware scheduling: distributed training placement で network topology を考慮

Security Hardening

  • Sigstore integration: container image 向け native supply chain security
  • Policy as Code maturity: より complex な scenario を cover する CEL-based admission
  • Confidential containers: TEE-based container isolation
  • Improved audit logging: structured で queryable な audit event

Developer Experience

  • KYAML ecosystem: より安全な YAML subset 向け tooling improvement
  • Improved CRD experience: より良い validation、defaulting、conversion
  • Enhanced kubectl: より強力な query、filtering、formatting option
TrendKey ProjectsKubernetes Impact
Platform EngineeringBackstage, Crossplane, KROplatform を構築するための platform としての Kubernetes
eBPF NetworkingCilium, Calico eBPFiptables/nftables を完全に置き換え
Service Mesh EvolutionIstio Ambient, Cilium SMsidecar-free mesh architectures
GitOps MaturityArgoCD, FluxCDdefault としての declarative operations
ObservabilityOpenTelemetryunified telemetry collection standard
WebAssembly (Wasm)SpinKube, wasmCloudより lightweight な workload execution
AI InfrastructureKubeAI, vLLM operatorKubernetes-native AI serving

Planning for the Future

Kubernetes strategy を計画する team 向けの推奨事項:

  1. Stay within n-1 of latest: latest EKS release から 1 version 以上遅れないことを target にする
  2. Upgrade quarterly: Kubernetes release cadence(4 か月ごと)に合わせる
  3. Test early: EKS availability から数週間以内に staging cluster で new version を validate
  4. Automate upgrades: cluster upgrade testing を含む CI/CD pipeline に投資する
  5. Monitor deprecations: Kubernetes release announcement を subscribe し、changelog を proactive に review
  6. Adopt GA features promptly: GA に到達した feature は production-ready であり、恒久的に enabled になります

10. References

Official Kubernetes Resources

Amazon EKS Resources

Tools for Upgrade Planning

Community Resources

Quiz

この document で学んだ内容を確認するには、Kubernetes Version Features and Roadmap Quiz に挑戦してください。


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