EKS Security Best Practices

サポート対象バージョン: Amazon EKS 1.31, 1.32, 1.33 最終更新: February 22, 2026

このドキュメントでは、Amazon EKS 環境のセキュリティベストプラクティスについて説明します。IAM 統合からネットワークセキュリティ、ランタイム保護まで、EKS クラスターを安全に運用する方法を学びます。

IRSA (IAM Roles for Service Accounts)
EKS Pod Identity
Security Groups for Pods
VPC Endpoints
Control Plane Logging
GuardDuty EKS Protection
Amazon Inspector
CIS Kubernetes Benchmark
Cluster Encryption
Node Security
Private Clusters
Multi-tenancy Patterns

IRSA (IAM Roles for Service Accounts)

IRSA Overview

IRSA (IAM Roles for Service Accounts) は、IAM ロールを Kubernetes ServiceAccounts に関連付け、Pods が AWS サービスへ安全にアクセスできるようにします。

┌─────────────────────────────────────────────────────────────────────────┐
│                           IRSA Architecture                              │
│                                                                         │
│  ┌─────────────┐                              ┌─────────────────────┐  │
│  │   EKS Pod   │                              │     AWS IAM         │  │
│  │             │                              │                     │  │
│  │ ServiceAcc  │──────┐                       │  ┌───────────────┐  │  │
│  │ (with IRSA) │      │                       │  │   IAM Role    │  │  │
│  └─────────────┘      │                       │  │               │  │  │
│         │             │                       │  │ Trust Policy: │  │  │
│         │             │                       │  │ OIDC Provider │  │  │
│         ▼             │                       │  └───────┬───────┘  │  │
│  ┌─────────────┐      │   ┌─────────────┐    │          │          │  │
│  │ Projected   │      │   │    OIDC     │    │          │          │  │
│  │   Token     │──────┴──▶│  Provider   │────┼──────────┘          │  │
│  └─────────────┘          └─────────────┘    │                     │  │
│                                              │  ┌───────────────┐  │  │
│                                              │  │ AWS Services  │  │  │
│                                              │  │ (S3, DynamoDB)│  │  │
│                                              │  └───────────────┘  │  │
└─────────────────────────────────────────────────────────────────────────┘

IRSA Setup

bash

# 1. Create OIDC Provider (once per cluster)
eksctl utils associate-iam-oidc-provider \
    --cluster my-cluster \
    --approve

# 2. Create IAM policy
cat <<EOF > s3-policy.json
{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "s3:GetObject",
                "s3:ListBucket"
            ],
            "Resource": [
                "arn:aws:s3:::my-bucket",
                "arn:aws:s3:::my-bucket/*"
            ]
        }
    ]
}
EOF

aws iam create-policy \
    --policy-name S3ReadPolicy \
    --policy-document file://s3-policy.json

# 3. Create IAM ServiceAccount
eksctl create iamserviceaccount \
    --name s3-reader-sa \
    --namespace production \
    --cluster my-cluster \
    --attach-policy-arn arn:aws:iam::123456789012:policy/S3ReadPolicy \
    --approve

Using IRSA

yaml

# Verify ServiceAccount
apiVersion: v1
kind: ServiceAccount
metadata:
  name: s3-reader-sa
  namespace: production
  annotations:
    # IRSA role ARN
    eks.amazonaws.com/role-arn: arn:aws:iam::123456789012:role/eksctl-my-cluster-s3-reader-sa
---
# Use ServiceAccount in Pod
apiVersion: v1
kind: Pod
metadata:
  name: s3-reader
  namespace: production
spec:
  serviceAccountName: s3-reader-sa
  containers:
  - name: app
    image: amazon/aws-cli
    command: ["aws", "s3", "ls", "s3://my-bucket"]
    # AWS SDK automatically uses IRSA token

IRSA Trust Policy

json

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": {
                "Federated": "arn:aws:iam::123456789012:oidc-provider/oidc.eks.us-east-1.amazonaws.com/id/EXAMPLED539D4633E53DE1B71EXAMPLE"
            },
            "Action": "sts:AssumeRoleWithWebIdentity",
            "Condition": {
                "StringEquals": {
                    "oidc.eks.us-east-1.amazonaws.com/id/EXAMPLED539D4633E53DE1B71EXAMPLE:sub": "system:serviceaccount:production:s3-reader-sa",
                    "oidc.eks.us-east-1.amazonaws.com/id/EXAMPLED539D4633E53DE1B71EXAMPLE:aud": "sts.amazonaws.com"
                }
            }
        }
    ]
}

IRSA Best Practices

yaml

# 1. Principle of least privilege
# Grant only minimum required permissions to each ServiceAccount

# 2. Separate ServiceAccounts per namespace
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: dynamodb-reader
  namespace: orders-service
  annotations:
    eks.amazonaws.com/role-arn: arn:aws:iam::123456789012:role/orders-dynamodb-role
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: s3-uploader
  namespace: media-service
  annotations:
    eks.amazonaws.com/role-arn: arn:aws:iam::123456789012:role/media-s3-role

EKS Pod Identity

Pod Identity Overview

EKS Pod Identity は IRSA の後継であり、よりシンプルな設定と強化されたセキュリティを提供します。

┌─────────────────────────────────────────────────────────────────────────┐
│                      EKS Pod Identity Architecture                       │
│                                                                         │
│  ┌─────────────┐         ┌─────────────────┐         ┌──────────────┐  │
│  │   EKS Pod   │────────▶│  Pod Identity   │────────▶│   AWS IAM    │  │
│  │             │         │     Agent       │         │    Role      │  │
│  │ ServiceAcc  │         │  (DaemonSet)    │         │              │  │
│  └─────────────┘         └─────────────────┘         └──────────────┘  │
│                                                                         │
│  Benefits:                                                              │
│  • No OIDC Provider setup required                                      │
│  • Easy role reuse                                                      │
│  • Enhanced audit logging                                               │
│  • Session tags support                                                 │
└─────────────────────────────────────────────────────────────────────────┘

Pod Identity Setup

bash

# 1. Install Pod Identity Agent addon
aws eks create-addon \
    --cluster-name my-cluster \
    --addon-name eks-pod-identity-agent \
    --addon-version v1.3.0-eksbuild.1

# 2. Create IAM role (with Pod Identity trust policy)
cat <<EOF > trust-policy.json
{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Principal": {
                "Service": "pods.eks.amazonaws.com"
            },
            "Action": [
                "sts:AssumeRole",
                "sts:TagSession"
            ]
        }
    ]
}
EOF

aws iam create-role \
    --role-name my-pod-role \
    --assume-role-policy-document file://trust-policy.json

# 3. Attach policy
aws iam attach-role-policy \
    --role-name my-pod-role \
    --policy-arn arn:aws:iam::123456789012:policy/S3ReadPolicy

# 4. Create Pod Identity Association
aws eks create-pod-identity-association \
    --cluster-name my-cluster \
    --namespace production \
    --service-account my-app-sa \
    --role-arn arn:aws:iam::123456789012:role/my-pod-role

Using Pod Identity

yaml

# ServiceAccount (no annotation needed)
apiVersion: v1
kind: ServiceAccount
metadata:
  name: my-app-sa
  namespace: production
---
# Pod
apiVersion: v1
kind: Pod
metadata:
  name: my-app
  namespace: production
spec:
  serviceAccountName: my-app-sa
  containers:
  - name: app
    image: myapp:latest
    # AWS SDK automatically uses Pod Identity

IRSA vs Pod Identity Comparison

Feature	IRSA	EKS Pod Identity
Setup Complexity	OIDC Provider required	Simple (API call)
Trust Policy	OIDC conditions required	Simple service principal
Role Reuse	Per-cluster modification needed	Reuse across clusters
Audit Logging	CloudTrail (SA level)	CloudTrail (Pod level)
Session Tags	Not supported	Supported
Recommended	Existing environments	New environments

Security Groups for Pods

Overview

Security Groups for Pods は、VPC Security Groups を Pods に直接適用し、ネットワークレベルの分離を提供します。

Prerequisites

bash

# Check VPC CNI version (v1.7.7+)
kubectl describe daemonset aws-node -n kube-system | grep Image

# Enable Security Groups for Pods
kubectl set env daemonset aws-node -n kube-system ENABLE_POD_ENI=true

# Add policy to node IAM role
aws iam attach-role-policy \
    --role-name <node-role-name> \
    --policy-arn arn:aws:iam::aws:policy/AmazonEKSVPCResourceController

SecurityGroupPolicy Configuration

yaml

apiVersion: vpcresources.k8s.aws/v1beta1
kind: SecurityGroupPolicy
metadata:
  name: database-sg-policy
  namespace: production
spec:
  # Target Pod selection
  podSelector:
    matchLabels:
      app: database
  # Security Groups to apply
  securityGroups:
    groupIds:
      - sg-0123456789abcdef0  # Database SG
      - sg-0987654321fedcba0  # Common monitoring SG

Security Group Configuration with Terraform

hcl

# Security Group for database Pods
resource "aws_security_group" "database_pods" {
  name_prefix = "database-pods-"
  vpc_id      = module.vpc.vpc_id
  description = "Security group for database pods"

  # PostgreSQL access (from app pods only)
  ingress {
    from_port       = 5432
    to_port         = 5432
    protocol        = "tcp"
    security_groups = [aws_security_group.app_pods.id]
    description     = "PostgreSQL from app pods"
  }

  # Monitoring access
  ingress {
    from_port       = 9187
    to_port         = 9187
    protocol        = "tcp"
    security_groups = [aws_security_group.monitoring.id]
    description     = "Postgres exporter metrics"
  }

  # Replication traffic
  ingress {
    from_port = 5432
    to_port   = 5432
    protocol  = "tcp"
    self      = true
    description = "Replication between database pods"
  }

  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }

  tags = {
    Name = "database-pods-sg"
  }
}

# SecurityGroupPolicy
resource "kubernetes_manifest" "database_sg_policy" {
  manifest = {
    apiVersion = "vpcresources.k8s.aws/v1beta1"
    kind       = "SecurityGroupPolicy"
    metadata = {
      name      = "database-sg-policy"
      namespace = "production"
    }
    spec = {
      podSelector = {
        matchLabels = {
          app = "database"
        }
      }
      securityGroups = {
        groupIds = [aws_security_group.database_pods.id]
      }
    }
  }
}

VPC Endpoints

VPC Endpoints for Private EKS

┌─────────────────────────────────────────────────────────────────────────┐
│                    EKS VPC Endpoint Configuration                        │
│                                                                         │
│  ┌──────────────────────────────────────────────────────────────────┐  │
│  │                         VPC                                       │  │
│  │                                                                   │  │
│  │  ┌─────────────┐    ┌─────────────┐    ┌─────────────┐          │  │
│  │  │  Private    │    │  Private    │    │  Private    │          │  │
│  │  │  Subnet A   │    │  Subnet B   │    │  Subnet C   │          │  │
│  │  │             │    │             │    │             │          │  │
│  │  │ ┌─────────┐ │    │ ┌─────────┐ │    │ ┌─────────┐ │          │  │
│  │  │ │  Node   │ │    │ │  Node   │ │    │ │  Node   │ │          │  │
│  │  │ └─────────┘ │    │ └─────────┘ │    │ └─────────┘ │          │  │
│  │  └──────┬──────┘    └──────┬──────┘    └──────┬──────┘          │  │
│  │         │                  │                  │                  │  │
│  │         └──────────────────┼──────────────────┘                  │  │
│  │                            │                                     │  │
│  │                            ▼                                     │  │
│  │  ┌─────────────────────────────────────────────────────────────┐│  │
│  │  │                   VPC Endpoints                              ││  │
│  │  │  • com.amazonaws.region.eks                                  ││  │
│  │  │  • com.amazonaws.region.ecr.api                              ││  │
│  │  │  • com.amazonaws.region.ecr.dkr                              ││  │
│  │  │  • com.amazonaws.region.s3 (Gateway)                         ││  │
│  │  │  • com.amazonaws.region.sts                                  ││  │
│  │  │  • com.amazonaws.region.logs                                 ││  │
│  │  │  • com.amazonaws.region.elasticloadbalancing                 ││  │
│  │  └─────────────────────────────────────────────────────────────┘│  │
│  └──────────────────────────────────────────────────────────────────┘  │
└─────────────────────────────────────────────────────────────────────────┘

Terraform VPC Endpoint Setup

hcl

# Interface endpoints
locals {
  interface_endpoints = [
    "com.amazonaws.${var.region}.eks",
    "com.amazonaws.${var.region}.ecr.api",
    "com.amazonaws.${var.region}.ecr.dkr",
    "com.amazonaws.${var.region}.sts",
    "com.amazonaws.${var.region}.logs",
    "com.amazonaws.${var.region}.elasticloadbalancing",
    "com.amazonaws.${var.region}.autoscaling",
    "com.amazonaws.${var.region}.ssm",
    "com.amazonaws.${var.region}.ssmmessages",
    "com.amazonaws.${var.region}.ec2messages",
  ]
}

resource "aws_vpc_endpoint" "interface_endpoints" {
  for_each = toset(local.interface_endpoints)

  vpc_id              = module.vpc.vpc_id
  service_name        = each.value
  vpc_endpoint_type   = "Interface"
  subnet_ids          = module.vpc.private_subnets
  security_group_ids  = [aws_security_group.vpc_endpoints.id]
  private_dns_enabled = true

  tags = {
    Name = "vpce-${split(".", each.value)[4]}"
  }
}

# Gateway endpoints (S3, DynamoDB)
resource "aws_vpc_endpoint" "s3" {
  vpc_id            = module.vpc.vpc_id
  service_name      = "com.amazonaws.${var.region}.s3"
  vpc_endpoint_type = "Gateway"
  route_table_ids   = module.vpc.private_route_table_ids

  tags = {
    Name = "vpce-s3"
  }
}

# Security Group for VPC endpoints
resource "aws_security_group" "vpc_endpoints" {
  name_prefix = "vpc-endpoints-"
  vpc_id      = module.vpc.vpc_id
  description = "Security group for VPC endpoints"

  ingress {
    from_port   = 443
    to_port     = 443
    protocol    = "tcp"
    cidr_blocks = [module.vpc.vpc_cidr_block]
    description = "HTTPS from VPC"
  }

  tags = {
    Name = "vpc-endpoints-sg"
  }
}

Control Plane Logging

EKS Control Plane Log Types

Log Type	Description	Use Case
api	Kubernetes API server logs	API call tracing, troubleshooting
audit	Kubernetes audit logs	Security auditing, compliance
authenticator	AWS IAM authenticator logs	Authentication debugging
controllerManager	Controller manager logs	Controller behavior tracking
scheduler	Scheduler logs	Pod scheduling troubleshooting

Enabling Logging

bash

# Enable logging with AWS CLI
aws eks update-cluster-config \
    --name my-cluster \
    --logging '{"clusterLogging":[{"types":["api","audit","authenticator","controllerManager","scheduler"],"enabled":true}]}'

hcl

# Terraform logging configuration
resource "aws_eks_cluster" "main" {
  name     = "my-cluster"
  role_arn = aws_iam_role.cluster.arn
  version  = "1.31"

  vpc_config {
    subnet_ids              = module.vpc.private_subnets
    endpoint_private_access = true
    endpoint_public_access  = true
  }

  enabled_cluster_log_types = [
    "api",
    "audit",
    "authenticator",
    "controllerManager",
    "scheduler"
  ]
}

CloudWatch Logs Insights Queries

sql

-- Find failed authentication attempts
fields @timestamp, @message
| filter @logStream like /authenticator/
| filter @message like /error/
| sort @timestamp desc
| limit 100

-- Track API calls for specific user
fields @timestamp, user.username, verb, requestURI, responseStatus.code
| filter @logStream like /audit/
| filter user.username = "admin"
| sort @timestamp desc
| limit 50

-- Permission denied requests
fields @timestamp, user.username, verb, requestURI, responseStatus.code
| filter @logStream like /audit/
| filter responseStatus.code = 403
| sort @timestamp desc
| limit 100

-- Secret access audit
fields @timestamp, user.username, verb, requestURI
| filter @logStream like /audit/
| filter requestURI like /secrets/
| sort @timestamp desc
| limit 100

GuardDuty EKS Protection

GuardDuty EKS Protection Overview

Amazon GuardDuty EKS Protection は、EKS クラスター内の悪意のあるアクティビティと異常な挙動を検出します。

┌─────────────────────────────────────────────────────────────────────────┐
│                    GuardDuty EKS Protection                              │
│                                                                         │
│  ┌─────────────────────────────────────────────────────────────────┐   │
│  │                    Detection Areas                               │   │
│  │                                                                  │   │
│  │  ┌─────────────┐  ┌─────────────┐  ┌─────────────┐             │   │
│  │  │ EKS Audit   │  │  Runtime    │  │  VPC Flow   │             │   │
│  │  │    Logs     │  │ Monitoring  │  │    Logs     │             │   │
│  │  └──────┬──────┘  └──────┬──────┘  └──────┬──────┘             │   │
│  │         │                │                │                     │   │
│  │         └────────────────┼────────────────┘                     │   │
│  │                          │                                      │   │
│  │                          ▼                                      │   │
│  │              ┌───────────────────────┐                         │   │
│  │              │    GuardDuty ML       │                         │   │
│  │              │  Threat Detection     │                         │   │
│  │              └───────────┬───────────┘                         │   │
│  │                          │                                      │   │
│  │                          ▼                                      │   │
│  │              ┌───────────────────────┐                         │   │
│  │              │      Findings         │                         │   │
│  │              │  (Security Events)    │                         │   │
│  │              └───────────────────────┘                         │   │
│  └─────────────────────────────────────────────────────────────────┘   │
└─────────────────────────────────────────────────────────────────────────┘

Enabling GuardDuty

bash

# Enable GuardDuty
aws guardduty create-detector --enable

# Enable EKS Protection
DETECTOR_ID=$(aws guardduty list-detectors --query 'DetectorIds[0]' --output text)

aws guardduty update-detector \
    --detector-id $DETECTOR_ID \
    --features '[
        {"Name": "EKS_AUDIT_LOGS", "Status": "ENABLED"},
        {"Name": "EKS_RUNTIME_MONITORING", "Status": "ENABLED",
         "AdditionalConfiguration": [
            {"Name": "EKS_ADDON_MANAGEMENT", "Status": "ENABLED"}
         ]
        }
    ]'

GuardDuty EKS Finding Types

Finding Type	Description	Severity
`Kubernetes:MaliciousIPCaller.Custom`	API call from known malicious IP	High
`Kubernetes:SuccessfulAnonymousAccess`	Successful API call by anonymous user	Medium
`Kubernetes:PrivilegedContainer`	Privileged container creation	Medium
`Kubernetes:AnomalousBehavior.PermissionChecked`	Anomalous permission check	Low
`Runtime:Cryptocurrency.CoinMiner`	Cryptocurrency mining activity	High
`Runtime:ReverseShell`	Reverse shell connection	Critical
`Runtime:Execution.Suspicious`	Suspicious process execution	Medium

Automated Finding Response

yaml

# EventBridge Rule
Resources:
  GuardDutyEKSRule:
    Type: AWS::Events::Rule
    Properties:
      Name: guardduty-eks-findings
      EventPattern:
        source:
          - aws.guardduty
        detail-type:
          - GuardDuty Finding
        detail:
          type:
            - prefix: Kubernetes
            - prefix: Runtime
      Targets:
        - Id: SNSTarget
          Arn: !Ref GuardDutyAlertTopic
        - Id: LambdaTarget
          Arn: !GetAtt GuardDutyResponseFunction.Arn

  GuardDutyResponseFunction:
    Type: AWS::Lambda::Function
    Properties:
      FunctionName: guardduty-eks-response
      Runtime: python3.11
      Handler: index.handler
      Code:
        ZipFile: |
          import boto3
          import json

          def handler(event, context):
              finding = event['detail']
              severity = finding['severity']

              if severity >= 7:  # High severity
                  # Auto-response: Pod isolation
                  eks = boto3.client('eks')
                  # Additional response logic...

              return {'statusCode': 200}

Amazon Inspector

Inspector Container Image Scanning

bash

# Enable ECR enhanced scanning
aws ecr put-registry-scanning-configuration \
    --scan-type ENHANCED \
    --rules '[
        {
            "repositoryFilters": [{"filter": "*", "filterType": "WILDCARD"}],
            "scanFrequency": "CONTINUOUS_SCAN"
        }
    ]'

# Get scan results
aws ecr describe-image-scan-findings \
    --repository-name my-app \
    --image-id imageTag=latest

Inspector and CI/CD Integration

yaml

# GitHub Actions example
name: Build and Scan

on:
  push:
    branches: [main]

jobs:
  build-scan-push:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Configure AWS credentials
        uses: aws-actions/configure-aws-credentials@v4
        with:
          aws-region: us-east-1

      - name: Login to Amazon ECR
        uses: aws-actions/amazon-ecr-login@v2

      - name: Build and push image
        run: |
          docker build -t $ECR_REGISTRY/my-app:${{ github.sha }} .
          docker push $ECR_REGISTRY/my-app:${{ github.sha }}

      - name: Wait for Inspector scan
        run: |
          sleep 60  # Wait for Inspector to complete scan

      - name: Check scan results
        run: |
          FINDINGS=$(aws ecr describe-image-scan-findings \
            --repository-name my-app \
            --image-id imageTag=${{ github.sha }} \
            --query 'imageScanFindings.findingSeverityCounts')

          CRITICAL=$(echo $FINDINGS | jq '.CRITICAL // 0')
          HIGH=$(echo $FINDINGS | jq '.HIGH // 0')

          if [ "$CRITICAL" -gt 0 ] || [ "$HIGH" -gt 5 ]; then
            echo "Security scan failed: CRITICAL=$CRITICAL, HIGH=$HIGH"
            exit 1
          fi

CIS Kubernetes Benchmark

Running kube-bench

bash

# Run kube-bench as a Job
kubectl apply -f - <<EOF
apiVersion: batch/v1
kind: Job
metadata:
  name: kube-bench
  namespace: kube-system
spec:
  template:
    spec:
      hostPID: true
      containers:
      - name: kube-bench
        image: aquasec/kube-bench:latest
        command: ["kube-bench", "--benchmark", "eks-1.4.0"]
        volumeMounts:
        - name: var-lib-kubelet
          mountPath: /var/lib/kubelet
          readOnly: true
        - name: etc-systemd
          mountPath: /etc/systemd
          readOnly: true
        - name: etc-kubernetes
          mountPath: /etc/kubernetes
          readOnly: true
      restartPolicy: Never
      volumes:
      - name: var-lib-kubelet
        hostPath:
          path: /var/lib/kubelet
      - name: etc-systemd
        hostPath:
          path: /etc/systemd
      - name: etc-kubernetes
        hostPath:
          path: /etc/kubernetes
EOF

# Check results
kubectl logs job/kube-bench -n kube-system

CIS Benchmark Key Sections

Section	Description	EKS Relevance
1. Control Plane	API server, etcd, etc.	AWS managed
2. etcd	etcd security	AWS managed
3. Control Plane Configuration	Controllers, scheduler	AWS managed
4. Worker Nodes	Node configuration	User responsibility
5. Policies	RBAC, PSP/PSS, network	User responsibility

Automated Compliance Checks

yaml

# CronJob for regular checks
apiVersion: batch/v1
kind: CronJob
metadata:
  name: cis-benchmark-scan
  namespace: security
spec:
  schedule: "0 2 * * 0"  # Every Sunday at 02:00
  jobTemplate:
    spec:
      template:
        spec:
          serviceAccountName: cis-scanner
          containers:
          - name: kube-bench
            image: aquasec/kube-bench:latest
            command:
            - /bin/sh
            - -c
            - |
              kube-bench --benchmark eks-1.4.0 --json > /tmp/results.json
              # Upload results to S3
              aws s3 cp /tmp/results.json s3://security-reports/cis-benchmark/$(date +%Y-%m-%d).json
          restartPolicy: OnFailure

Cluster Encryption

EKS Secrets Encryption (KMS)

bash

# Create KMS key
aws kms create-key \
    --description "EKS Secrets Encryption Key" \
    --key-usage ENCRYPT_DECRYPT

# Create cluster with encryption
aws eks create-cluster \
    --name my-cluster \
    --role-arn arn:aws:iam::123456789012:role/EKSClusterRole \
    --resources-vpc-config subnetIds=subnet-xxx,subnet-yyy \
    --encryption-config '[{
        "resources": ["secrets"],
        "provider": {
            "keyArn": "arn:aws:kms:us-east-1:123456789012:key/xxx-xxx"
        }
    }]'

hcl

# Terraform configuration
resource "aws_kms_key" "eks_secrets" {
  description             = "EKS Secrets Encryption Key"
  deletion_window_in_days = 7
  enable_key_rotation     = true

  policy = jsonencode({
    Version = "2012-10-17"
    Statement = [
      {
        Sid    = "Enable IAM policies"
        Effect = "Allow"
        Principal = {
          AWS = "arn:aws:iam::${data.aws_caller_identity.current.account_id}:root"
        }
        Action   = "kms:*"
        Resource = "*"
      }
    ]
  })
}

resource "aws_eks_cluster" "main" {
  name     = "my-cluster"
  role_arn = aws_iam_role.cluster.arn

  encryption_config {
    resources = ["secrets"]
    provider {
      key_arn = aws_kms_key.eks_secrets.arn
    }
  }

  # ... other configuration
}

Node Security

Bottlerocket OS

hcl

# Bottlerocket node group
resource "aws_eks_node_group" "bottlerocket" {
  cluster_name    = aws_eks_cluster.main.name
  node_group_name = "bottlerocket-nodes"
  node_role_arn   = aws_iam_role.node.arn
  subnet_ids      = module.vpc.private_subnets

  ami_type       = "BOTTLEROCKET_x86_64"
  instance_types = ["m5.large"]

  scaling_config {
    desired_size = 3
    max_size     = 10
    min_size     = 1
  }

  # Bottlerocket configuration
  launch_template {
    id      = aws_launch_template.bottlerocket.id
    version = aws_launch_template.bottlerocket.latest_version
  }
}

resource "aws_launch_template" "bottlerocket" {
  name_prefix = "bottlerocket-"

  user_data = base64encode(<<-EOF
    [settings.kubernetes]
    cluster-name = "${aws_eks_cluster.main.name}"
    api-server = "${aws_eks_cluster.main.endpoint}"
    cluster-certificate = "${aws_eks_cluster.main.certificate_authority[0].data}"

    [settings.kubernetes.node-labels]
    "node.kubernetes.io/os" = "bottlerocket"

    [settings.kernel.sysctl]
    "net.core.rmem_max" = "16777216"
    "net.core.wmem_max" = "16777216"
  EOF
  )
}

Node Security Hardening

yaml

# Pod scheduling based on node labels
apiVersion: v1
kind: Pod
metadata:
  name: secure-app
spec:
  nodeSelector:
    node.kubernetes.io/os: bottlerocket
  tolerations:
  - key: "security"
    operator: "Equal"
    value: "high"
    effect: "NoSchedule"
  containers:
  - name: app
    image: myapp:latest
    securityContext:
      readOnlyRootFilesystem: true
      runAsNonRoot: true

Private Clusters

Fully Private EKS Configuration

hcl

resource "aws_eks_cluster" "private" {
  name     = "private-cluster"
  role_arn = aws_iam_role.cluster.arn
  version  = "1.31"

  vpc_config {
    subnet_ids              = module.vpc.private_subnets
    endpoint_private_access = true
    endpoint_public_access  = false  # Disable public endpoint
    security_group_ids      = [aws_security_group.cluster.id]
  }

  # Control plane logging
  enabled_cluster_log_types = [
    "api", "audit", "authenticator", "controllerManager", "scheduler"
  ]

  # Secrets encryption
  encryption_config {
    resources = ["secrets"]
    provider {
      key_arn = aws_kms_key.eks.arn
    }
  }

  depends_on = [
    aws_iam_role_policy_attachment.cluster_policy,
    aws_cloudwatch_log_group.cluster,
  ]
}

Bastion or VPN Access

hcl

# Client VPN endpoint
resource "aws_ec2_client_vpn_endpoint" "eks_access" {
  description            = "EKS Access VPN"
  server_certificate_arn = aws_acm_certificate.vpn.arn
  client_cidr_block      = "10.100.0.0/16"

  authentication_options {
    type                       = "certificate-authentication"
    root_certificate_chain_arn = aws_acm_certificate.vpn_root.arn
  }

  connection_log_options {
    enabled              = true
    cloudwatch_log_group = aws_cloudwatch_log_group.vpn.name
  }

  vpc_id             = module.vpc.vpc_id
  security_group_ids = [aws_security_group.vpn.id]

  split_tunnel = true
}

resource "aws_ec2_client_vpn_network_association" "eks_access" {
  count                  = length(module.vpc.private_subnets)
  client_vpn_endpoint_id = aws_ec2_client_vpn_endpoint.eks_access.id
  subnet_id              = module.vpc.private_subnets[count.index]
}

Multi-tenancy Patterns

Namespace-based Multi-tenancy

yaml

---
# Tenant namespace
apiVersion: v1
kind: Namespace
metadata:
  name: tenant-a
  labels:
    tenant: tenant-a
    environment: production
    pod-security.kubernetes.io/enforce: restricted
---
# ResourceQuota
apiVersion: v1
kind: ResourceQuota
metadata:
  name: tenant-a-quota
  namespace: tenant-a
spec:
  hard:
    requests.cpu: "10"
    requests.memory: 20Gi
    limits.cpu: "20"
    limits.memory: 40Gi
    persistentvolumeclaims: "10"
    services.loadbalancers: "2"
---
# LimitRange
apiVersion: v1
kind: LimitRange
metadata:
  name: tenant-a-limits
  namespace: tenant-a
spec:
  limits:
  - default:
      cpu: 500m
      memory: 512Mi
    defaultRequest:
      cpu: 100m
      memory: 128Mi
    max:
      cpu: "2"
      memory: 4Gi
    min:
      cpu: 50m
      memory: 64Mi
    type: Container
---
# NetworkPolicy (tenant isolation)
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: tenant-isolation
  namespace: tenant-a
spec:
  podSelector: {}
  policyTypes:
    - Ingress
    - Egress
  ingress:
    - from:
        - namespaceSelector:
            matchLabels:
              tenant: tenant-a
  egress:
    - to:
        - namespaceSelector:
            matchLabels:
              tenant: tenant-a
    - to:
        - namespaceSelector:
            matchLabels:
              kubernetes.io/metadata.name: kube-system
      ports:
        - port: 53
          protocol: UDP

RBAC Multi-tenancy

yaml

---
# Tenant admin role
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: tenant-admin
  namespace: tenant-a
rules:
  - apiGroups: [""]
    resources: ["pods", "services", "configmaps", "secrets"]
    verbs: ["*"]
  - apiGroups: ["apps"]
    resources: ["deployments", "statefulsets", "daemonsets"]
    verbs: ["*"]
  - apiGroups: ["networking.k8s.io"]
    resources: ["ingresses"]
    verbs: ["*"]
---
# Tenant admin binding
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: tenant-a-admins
  namespace: tenant-a
subjects:
  - kind: Group
    name: tenant-a-admins
    apiGroup: rbac.authorization.k8s.io
roleRef:
  kind: Role
  name: tenant-admin
  apiGroup: rbac.authorization.k8s.io

Summary

主要な EKS セキュリティベストプラクティス:

IAM 統合: IRSA または Pod Identity で AWS サービスへアクセスする
ネットワークセキュリティ: Security Groups for Pods、VPC endpoints
ロギングとモニタリング: Control plane logs、GuardDuty
イメージセキュリティ: Amazon Inspector、ECR scanning
コンプライアンス: CIS Benchmark、kube-bench
暗号化: KMS による Secrets encryption
Node セキュリティ: Bottlerocket OS、least privilege
マルチテナンシー: Namespace isolation、RBAC、ResourceQuota

エンドツーエンドのオブザーバビリティラボ

ArgoCD の詳細クイズ

Istio の詳細クイズ

Linkerd の詳細クイズ

Cilium サービスメッシュの詳細クイズ

Cilium 詳説

Calico 詳説

メトリクス

ログ記録

トレーシング

アラート通知

可観測性の演習

ArgoCD

トラフィック管理

セキュリティ

可観測性

レジリエンス

高度な設定

比較ガイド

メトリクス

ログ記録

トレーシング

アラート通知

EKS Security Best Practices ​

Table of Contents ​

IRSA (IAM Roles for Service Accounts) ​

IRSA Overview ​

IRSA Setup ​

Using IRSA ​

IRSA Trust Policy ​

IRSA Best Practices ​

EKS Pod Identity ​

Pod Identity Overview ​

Pod Identity Setup ​

Using Pod Identity ​

IRSA vs Pod Identity Comparison ​

Security Groups for Pods ​

Overview ​

Prerequisites ​

SecurityGroupPolicy Configuration ​

Security Group Configuration with Terraform ​

VPC Endpoints ​

VPC Endpoints for Private EKS ​

Terraform VPC Endpoint Setup ​

Control Plane Logging ​

EKS Control Plane Log Types ​

Enabling Logging ​

CloudWatch Logs Insights Queries ​

GuardDuty EKS Protection ​

GuardDuty EKS Protection Overview ​

Enabling GuardDuty ​

GuardDuty EKS Finding Types ​

Automated Finding Response ​

Amazon Inspector ​

Inspector Container Image Scanning ​

Inspector and CI/CD Integration ​

CIS Kubernetes Benchmark ​

Running kube-bench ​

CIS Benchmark Key Sections ​

Automated Compliance Checks ​

Cluster Encryption ​

EKS Secrets Encryption (KMS) ​

Node Security ​

Bottlerocket OS ​

Node Security Hardening ​

Private Clusters ​

Fully Private EKS Configuration ​

Bastion or VPN Access ​

Multi-tenancy Patterns ​

Namespace-based Multi-tenancy ​

RBAC Multi-tenancy ​

Summary ​

References ​

EKS Security Best Practices

Table of Contents

IRSA (IAM Roles for Service Accounts)

IRSA Overview

IRSA Setup

Using IRSA

IRSA Trust Policy

IRSA Best Practices

EKS Pod Identity

Pod Identity Overview

Pod Identity Setup

Using Pod Identity

IRSA vs Pod Identity Comparison

Security Groups for Pods

Overview

Prerequisites

SecurityGroupPolicy Configuration

Security Group Configuration with Terraform

VPC Endpoints

VPC Endpoints for Private EKS

Terraform VPC Endpoint Setup

Control Plane Logging

EKS Control Plane Log Types

Enabling Logging

CloudWatch Logs Insights Queries

GuardDuty EKS Protection

GuardDuty EKS Protection Overview

Enabling GuardDuty

GuardDuty EKS Finding Types

Automated Finding Response

Amazon Inspector

Inspector Container Image Scanning

Inspector and CI/CD Integration

CIS Kubernetes Benchmark

Running kube-bench

CIS Benchmark Key Sections

Automated Compliance Checks

Cluster Encryption

EKS Secrets Encryption (KMS)

Node Security

Bottlerocket OS

Node Security Hardening

Private Clusters

Fully Private EKS Configuration

Bastion or VPN Access

Multi-tenancy Patterns

Namespace-based Multi-tenancy

RBAC Multi-tenancy

Summary

References