Cilium Service Mesh Traffic Management

Supported Versions: Cilium 1.16+, Kubernetes 1.28+ Last Updated: February 22, 2026

Overview

Traffic management in Cilium Service Mesh combines eBPF-based L4 load balancing with Envoy-based L7 routing. This chapter explains advanced traffic management features through CiliumEnvoyConfig, L7 rules in CiliumNetworkPolicy, and Gateway API integration.

Traffic Management Architecture

CiliumEnvoyConfig

Basic Structure

CiliumEnvoyConfig defines Envoy configuration for specific services:

yaml

apiVersion: cilium.io/v2
kind: CiliumEnvoyConfig
metadata:
  name: my-service-config
  namespace: default
spec:
  # Services this configuration applies to
  services:
  - name: my-service
    namespace: default

  # Backend services (optional)
  backendServices:
  - name: backend-v1
    namespace: default
  - name: backend-v2
    namespace: default

  # Envoy resource definitions
  resources:
  - "@type": type.googleapis.com/envoy.config.listener.v3.Listener
    name: my-service-listener
    # ... listener configuration

HTTP Routing

Path-based Routing

yaml

apiVersion: cilium.io/v2
kind: CiliumEnvoyConfig
metadata:
  name: path-routing
  namespace: default
spec:
  services:
  - name: api-gateway
    namespace: default

  backendServices:
  - name: users-service
    namespace: default
  - name: orders-service
    namespace: default
  - name: products-service
    namespace: default

  resources:
  - "@type": type.googleapis.com/envoy.config.listener.v3.Listener
    name: api-gateway-listener
    filter_chains:
    - filters:
      - name: envoy.filters.network.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
          stat_prefix: api-gateway
          codec_type: AUTO
          route_config:
            name: api_routes
            virtual_hosts:
            - name: api
              domains: ["*"]
              routes:
              # /users/* -> users-service
              - match:
                  prefix: "/users"
                route:
                  cluster: default/users-service

              # /orders/* -> orders-service
              - match:
                  prefix: "/orders"
                route:
                  cluster: default/orders-service

              # /products/* -> products-service
              - match:
                  prefix: "/products"
                route:
                  cluster: default/products-service

              # Default route
              - match:
                  prefix: "/"
                direct_response:
                  status: 404
                  body:
                    inline_string: "Not Found"

          http_filters:
          - name: envoy.filters.http.router
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router

Header-based Routing

yaml

apiVersion: cilium.io/v2
kind: CiliumEnvoyConfig
metadata:
  name: header-routing
  namespace: default
spec:
  services:
  - name: api-service
    namespace: default

  backendServices:
  - name: api-v1
    namespace: default
  - name: api-v2
    namespace: default
  - name: api-beta
    namespace: default

  resources:
  - "@type": type.googleapis.com/envoy.config.listener.v3.Listener
    name: header-routing-listener
    filter_chains:
    - filters:
      - name: envoy.filters.network.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
          stat_prefix: api-service
          route_config:
            name: header_routes
            virtual_hosts:
            - name: api
              domains: ["*"]
              routes:
              # Route to v2 if X-API-Version: v2 header present
              - match:
                  prefix: "/"
                  headers:
                  - name: "X-API-Version"
                    exact_match: "v2"
                route:
                  cluster: default/api-v2

              # Route to beta if X-Beta-User: true header present
              - match:
                  prefix: "/"
                  headers:
                  - name: "X-Beta-User"
                    exact_match: "true"
                route:
                  cluster: default/api-beta

              # Default: route to v1
              - match:
                  prefix: "/"
                route:
                  cluster: default/api-v1

          http_filters:
          - name: envoy.filters.http.router
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router

Method-based Routing

yaml

apiVersion: cilium.io/v2
kind: CiliumEnvoyConfig
metadata:
  name: method-routing
  namespace: default
spec:
  services:
  - name: rest-api
    namespace: default

  backendServices:
  - name: read-service
    namespace: default
  - name: write-service
    namespace: default

  resources:
  - "@type": type.googleapis.com/envoy.config.listener.v3.Listener
    name: method-routing-listener
    filter_chains:
    - filters:
      - name: envoy.filters.network.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
          stat_prefix: rest-api
          route_config:
            name: method_routes
            virtual_hosts:
            - name: api
              domains: ["*"]
              routes:
              # GET requests -> read-service
              - match:
                  prefix: "/"
                  headers:
                  - name: ":method"
                    exact_match: "GET"
                route:
                  cluster: default/read-service

              # POST, PUT, DELETE -> write-service
              - match:
                  prefix: "/"
                  headers:
                  - name: ":method"
                    safe_regex_match:
                      google_re2: {}
                      regex: "POST|PUT|DELETE|PATCH"
                route:
                  cluster: default/write-service

          http_filters:
          - name: envoy.filters.http.router
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router

L7 Traffic Policies

CiliumNetworkPolicy L7 Rules

CiliumNetworkPolicy enables fine-grained traffic control at the L7 level:

yaml

apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
  name: l7-http-policy
  namespace: default
spec:
  endpointSelector:
    matchLabels:
      app: backend-api

  ingress:
  - fromEndpoints:
    - matchLabels:
        app: frontend
    toPorts:
    - ports:
      - port: "8080"
        protocol: TCP
      rules:
        http:
        # Allow GET /api/users/*
        - method: GET
          path: "/api/users/.*"

        # Allow GET /api/products/*
        - method: GET
          path: "/api/products/.*"

        # Allow POST /api/orders
        - method: POST
          path: "/api/orders"

        # With header conditions
        - method: GET
          path: "/api/admin/.*"
          headers:
          - "X-Admin-Token: secret-token"

Various Protocol Support

Kafka L7 Policy

yaml

apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
  name: kafka-l7-policy
  namespace: kafka
spec:
  endpointSelector:
    matchLabels:
      app: kafka-broker

  ingress:
  - fromEndpoints:
    - matchLabels:
        app: kafka-producer
    toPorts:
    - ports:
      - port: "9092"
        protocol: TCP
      rules:
        kafka:
        # Allow produce to specific topics
        - apiKey: "produce"
          topic: "orders"
        - apiKey: "produce"
          topic: "events"

  - fromEndpoints:
    - matchLabels:
        app: kafka-consumer
    toPorts:
    - ports:
      - port: "9092"
        protocol: TCP
      rules:
        kafka:
        # Allow fetch from specific topics
        - apiKey: "fetch"
          topic: "orders"
        - apiKey: "fetch"
          topic: "events"
        # Allow consumer group management
        - apiKey: "offsetcommit"
          topic: "orders"
        - apiKey: "offsetfetch"
          topic: "orders"

DNS L7 Policy

yaml

apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
  name: dns-l7-policy
  namespace: default
spec:
  endpointSelector:
    matchLabels:
      app: web-app

  egress:
  - toEndpoints:
    - matchLabels:
        k8s:io.kubernetes.pod.namespace: kube-system
        k8s-app: kube-dns
    toPorts:
    - ports:
      - port: "53"
        protocol: UDP
      rules:
        dns:
        # Allow specific domain lookups only
        - matchPattern: "*.example.com"
        - matchPattern: "api.external-service.io"
        - matchName: "database.internal.svc.cluster.local"

gRPC L7 Policy

yaml

apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
metadata:
  name: grpc-l7-policy
  namespace: default
spec:
  endpointSelector:
    matchLabels:
      app: grpc-server

  ingress:
  - fromEndpoints:
    - matchLabels:
        app: grpc-client
    toPorts:
    - ports:
      - port: "50051"
        protocol: TCP
      rules:
        http:
        # gRPC is HTTP/2 based, so use http rules
        - method: POST
          path: "/myapp.UserService/GetUser"
        - method: POST
          path: "/myapp.UserService/ListUsers"
        - method: POST
          path: "/myapp.OrderService/.*"

Load Balancing

L4 Load Balancing (eBPF)

eBPF-based L4 load balancing replaces kube-proxy:

yaml

# Cilium configuration (values.yaml)
kubeProxyReplacement: true

loadBalancer:
  # Load balancing algorithm
  algorithm: maglev  # maglev or random

  # Mode configuration
  mode: snat  # snat, dsr, or hybrid

  # DSR settings (optional)
  dsrDispatch: opt  # opt or ipip

  # Session affinity
  serviceTopology: true

  # Health checking
  healthCheckNodePort: true

Maglev Hashing

L7 Load Balancing (Envoy)

L7 load balancing is provided through Envoy:

yaml

apiVersion: cilium.io/v2
kind: CiliumEnvoyConfig
metadata:
  name: l7-load-balancing
  namespace: default
spec:
  services:
  - name: api-service
    namespace: default

  backendServices:
  - name: api-backend
    namespace: default

  resources:
  # Cluster definition
  - "@type": type.googleapis.com/envoy.config.cluster.v3.Cluster
    name: default/api-backend
    connect_timeout: 5s
    type: EDS
    eds_cluster_config:
      eds_config:
        api_config_source:
          api_type: GRPC
          grpc_services:
          - envoy_grpc:
              cluster_name: xds-grpc-cilium

    # Load balancing policy
    lb_policy: ROUND_ROBIN

    # Outlier detection (Circuit Breaker)
    outlier_detection:
      consecutive_5xx: 5
      interval: 10s
      base_ejection_time: 30s
      max_ejection_percent: 50

    # Health checks
    health_checks:
    - timeout: 5s
      interval: 10s
      unhealthy_threshold: 3
      healthy_threshold: 2
      http_health_check:
        path: "/health"
        expected_statuses:
        - start: 200
          end: 299

    # Connection pool settings
    circuit_breakers:
      thresholds:
      - priority: DEFAULT
        max_connections: 1000
        max_pending_requests: 1000
        max_requests: 1000
        max_retries: 3

Load Balancing Algorithm Options

yaml

# Round Robin
lb_policy: ROUND_ROBIN

# Least Request
lb_policy: LEAST_REQUEST
least_request_lb_config:
  choice_count: 2

# Random
lb_policy: RANDOM

# Ring Hash (Consistent Hashing)
lb_policy: RING_HASH
ring_hash_lb_config:
  hash_function: XX_HASH
  minimum_ring_size: 1024
  maximum_ring_size: 8388608

# Maglev
lb_policy: MAGLEV
maglev_lb_config:
  table_size: 65537

Traffic Splitting (Canary Deployment)

Weight-based Traffic Splitting

yaml

apiVersion: cilium.io/v2
kind: CiliumEnvoyConfig
metadata:
  name: canary-deployment
  namespace: default
spec:
  services:
  - name: frontend
    namespace: default

  backendServices:
  - name: frontend-stable
    namespace: default
  - name: frontend-canary
    namespace: default

  resources:
  - "@type": type.googleapis.com/envoy.config.listener.v3.Listener
    name: canary-listener
    filter_chains:
    - filters:
      - name: envoy.filters.network.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
          stat_prefix: frontend
          route_config:
            name: canary_routes
            virtual_hosts:
            - name: frontend
              domains: ["*"]
              routes:
              - match:
                  prefix: "/"
                route:
                  weighted_clusters:
                    clusters:
                    # 90% -> stable
                    - name: default/frontend-stable
                      weight: 90
                    # 10% -> canary
                    - name: default/frontend-canary
                      weight: 10
                    total_weight: 100

          http_filters:
          - name: envoy.filters.http.router
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router

Header-based Canary

yaml

apiVersion: cilium.io/v2
kind: CiliumEnvoyConfig
metadata:
  name: header-canary
  namespace: default
spec:
  services:
  - name: api
    namespace: default

  backendServices:
  - name: api-stable
    namespace: default
  - name: api-canary
    namespace: default

  resources:
  - "@type": type.googleapis.com/envoy.config.listener.v3.Listener
    name: header-canary-listener
    filter_chains:
    - filters:
      - name: envoy.filters.network.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
          stat_prefix: api
          route_config:
            name: header_canary_routes
            virtual_hosts:
            - name: api
              domains: ["*"]
              routes:
              # Route to canary if X-Canary: true header present
              - match:
                  prefix: "/"
                  headers:
                  - name: "X-Canary"
                    exact_match: "true"
                route:
                  cluster: default/api-canary

              # Default: route to stable
              - match:
                  prefix: "/"
                route:
                  cluster: default/api-stable

          http_filters:
          - name: envoy.filters.http.router
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router

Retry and Timeout

Retry Configuration

yaml

apiVersion: cilium.io/v2
kind: CiliumEnvoyConfig
metadata:
  name: retry-config
  namespace: default
spec:
  services:
  - name: api-service
    namespace: default

  backendServices:
  - name: api-backend
    namespace: default

  resources:
  - "@type": type.googleapis.com/envoy.config.listener.v3.Listener
    name: retry-listener
    filter_chains:
    - filters:
      - name: envoy.filters.network.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
          stat_prefix: api-service
          route_config:
            name: retry_routes
            virtual_hosts:
            - name: api
              domains: ["*"]
              routes:
              - match:
                  prefix: "/"
                route:
                  cluster: default/api-backend
                  timeout: 30s

                  # Retry policy
                  retry_policy:
                    # Status codes to retry
                    retry_on: "5xx,reset,connect-failure,retriable-4xx"

                    # Maximum retry attempts
                    num_retries: 3

                    # Retry interval
                    per_try_timeout: 10s

                    # Retry backoff
                    retry_back_off:
                      base_interval: 0.5s
                      max_interval: 10s

                    # Retriable headers
                    retriable_headers:
                    - name: "x-envoy-retriable-on"
                      exact_match: "true"

                    # Retry priority
                    retry_priority:
                      name: envoy.retry_priorities.previous_priorities
                      typed_config:
                        "@type": type.googleapis.com/envoy.extensions.retry.priority.previous_priorities.v3.PreviousPrioritiesConfig
                        update_frequency: 2

          http_filters:
          - name: envoy.filters.http.router
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router

Timeout Configuration

yaml

apiVersion: cilium.io/v2
kind: CiliumEnvoyConfig
metadata:
  name: timeout-config
  namespace: default
spec:
  services:
  - name: slow-service
    namespace: default

  resources:
  - "@type": type.googleapis.com/envoy.config.listener.v3.Listener
    name: timeout-listener
    filter_chains:
    - filters:
      - name: envoy.filters.network.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
          stat_prefix: slow-service

          # Connection timeout
          common_http_protocol_options:
            idle_timeout: 300s
            headers_with_underscores_action: REJECT_REQUEST

          # Stream timeouts
          stream_idle_timeout: 60s
          request_timeout: 120s

          route_config:
            name: timeout_routes
            virtual_hosts:
            - name: slow-service
              domains: ["*"]
              routes:
              # Default route
              - match:
                  prefix: "/"
                route:
                  cluster: default/slow-service
                  timeout: 60s

              # Endpoint requiring long processing time
              - match:
                  prefix: "/long-running"
                route:
                  cluster: default/slow-service
                  timeout: 300s

              # Streaming endpoint (unlimited)
              - match:
                  prefix: "/stream"
                route:
                  cluster: default/slow-service
                  timeout: 0s  # Unlimited

          http_filters:
          - name: envoy.filters.http.router
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router

Rate Limiting

Local Rate Limiting

yaml

apiVersion: cilium.io/v2
kind: CiliumEnvoyConfig
metadata:
  name: local-ratelimit
  namespace: default
spec:
  services:
  - name: api-service
    namespace: default

  resources:
  - "@type": type.googleapis.com/envoy.config.listener.v3.Listener
    name: ratelimit-listener
    filter_chains:
    - filters:
      - name: envoy.filters.network.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
          stat_prefix: api-service
          route_config:
            name: ratelimit_routes
            virtual_hosts:
            - name: api
              domains: ["*"]
              routes:
              - match:
                  prefix: "/"
                route:
                  cluster: default/api-service

          http_filters:
          # Local Rate Limiter
          - name: envoy.filters.http.local_ratelimit
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.local_ratelimit.v3.LocalRateLimit
              stat_prefix: http_local_rate_limiter

              # Global token bucket
              token_bucket:
                max_tokens: 1000
                tokens_per_fill: 100
                fill_interval: 1s

              # Response headers
              response_headers_to_add:
              - append_action: OVERWRITE_IF_EXISTS_OR_ADD
                header:
                  key: x-ratelimit-limit
                  value: "1000"
              - append_action: OVERWRITE_IF_EXISTS_OR_ADD
                header:
                  key: x-ratelimit-remaining
                  value: "%DYNAMIC_METADATA(envoy.http.local_rate_limit:remaining)%"

              # Response when rate limit exceeded
              status:
                code: TooManyRequests
              filter_enabled:
                runtime_key: local_rate_limit_enabled
                default_value:
                  numerator: 100
                  denominator: HUNDRED
              filter_enforced:
                runtime_key: local_rate_limit_enforced
                default_value:
                  numerator: 100
                  denominator: HUNDRED

          - name: envoy.filters.http.router
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router

Per-Route Rate Limiting

yaml

apiVersion: cilium.io/v2
kind: CiliumEnvoyConfig
metadata:
  name: per-route-ratelimit
  namespace: default
spec:
  services:
  - name: api-service
    namespace: default

  resources:
  - "@type": type.googleapis.com/envoy.config.listener.v3.Listener
    name: per-route-ratelimit-listener
    filter_chains:
    - filters:
      - name: envoy.filters.network.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
          stat_prefix: api-service
          route_config:
            name: ratelimit_routes
            virtual_hosts:
            - name: api
              domains: ["*"]
              routes:
              # Auth endpoint - low rate limit
              - match:
                  prefix: "/auth"
                route:
                  cluster: default/api-service
                typed_per_filter_config:
                  envoy.filters.http.local_ratelimit:
                    "@type": type.googleapis.com/envoy.extensions.filters.http.local_ratelimit.v3.LocalRateLimit
                    stat_prefix: auth_rate_limiter
                    token_bucket:
                      max_tokens: 10
                      tokens_per_fill: 5
                      fill_interval: 60s

              # Search endpoint - medium rate limit
              - match:
                  prefix: "/search"
                route:
                  cluster: default/api-service
                typed_per_filter_config:
                  envoy.filters.http.local_ratelimit:
                    "@type": type.googleapis.com/envoy.extensions.filters.http.local_ratelimit.v3.LocalRateLimit
                    stat_prefix: search_rate_limiter
                    token_bucket:
                      max_tokens: 100
                      tokens_per_fill: 50
                      fill_interval: 1s

              # Default - high rate limit
              - match:
                  prefix: "/"
                route:
                  cluster: default/api-service
                typed_per_filter_config:
                  envoy.filters.http.local_ratelimit:
                    "@type": type.googleapis.com/envoy.extensions.filters.http.local_ratelimit.v3.LocalRateLimit
                    stat_prefix: default_rate_limiter
                    token_bucket:
                      max_tokens: 1000
                      tokens_per_fill: 100
                      fill_interval: 1s

          http_filters:
          - name: envoy.filters.http.local_ratelimit
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.local_ratelimit.v3.LocalRateLimit
              stat_prefix: http_local_rate_limiter
          - name: envoy.filters.http.router
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router

URL Rewriting and Header Manipulation

URL Rewriting

yaml

apiVersion: cilium.io/v2
kind: CiliumEnvoyConfig
metadata:
  name: url-rewrite
  namespace: default
spec:
  services:
  - name: api-gateway
    namespace: default

  backendServices:
  - name: users-service
    namespace: default

  resources:
  - "@type": type.googleapis.com/envoy.config.listener.v3.Listener
    name: rewrite-listener
    filter_chains:
    - filters:
      - name: envoy.filters.network.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
          stat_prefix: api-gateway
          route_config:
            name: rewrite_routes
            virtual_hosts:
            - name: api
              domains: ["*"]
              routes:
              # /api/v1/users/* -> /users/*
              - match:
                  prefix: "/api/v1/users"
                route:
                  cluster: default/users-service
                  prefix_rewrite: "/users"

              # Regex rewrite
              - match:
                  safe_regex:
                    google_re2: {}
                    regex: "/v([0-9]+)/(.*)"
                route:
                  cluster: default/users-service
                  regex_rewrite:
                    pattern:
                      google_re2: {}
                      regex: "/v([0-9]+)/(.*)"
                    substitution: "/api/\\2?version=\\1"

              # Host rewrite
              - match:
                  prefix: "/legacy"
                route:
                  cluster: default/users-service
                  host_rewrite_literal: "legacy.internal.svc.cluster.local"
                  prefix_rewrite: "/"

          http_filters:
          - name: envoy.filters.http.router
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router

Header Manipulation

yaml

apiVersion: cilium.io/v2
kind: CiliumEnvoyConfig
metadata:
  name: header-manipulation
  namespace: default
spec:
  services:
  - name: api-service
    namespace: default

  resources:
  - "@type": type.googleapis.com/envoy.config.listener.v3.Listener
    name: header-listener
    filter_chains:
    - filters:
      - name: envoy.filters.network.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
          stat_prefix: api-service
          route_config:
            name: header_routes
            virtual_hosts:
            - name: api
              domains: ["*"]

              # Virtual host level headers
              request_headers_to_add:
              - header:
                  key: "X-Forwarded-By"
                  value: "cilium-envoy"
                append_action: OVERWRITE_IF_EXISTS_OR_ADD

              response_headers_to_add:
              - header:
                  key: "X-Served-By"
                  value: "cilium-service-mesh"
                append_action: OVERWRITE_IF_EXISTS_OR_ADD

              response_headers_to_remove:
              - "server"
              - "x-powered-by"

              routes:
              - match:
                  prefix: "/"
                route:
                  cluster: default/api-service

                  # Route level headers
                  request_headers_to_add:
                  - header:
                      key: "X-Request-Start"
                      value: "%START_TIME(%s.%3f)%"
                    append_action: OVERWRITE_IF_EXISTS_OR_ADD
                  - header:
                      key: "X-Envoy-Original-Path"
                      value: "%REQ(:PATH)%"
                    append_action: OVERWRITE_IF_EXISTS_OR_ADD

                  response_headers_to_add:
                  - header:
                      key: "X-Response-Time"
                      value: "%RESPONSE_DURATION%ms"
                    append_action: OVERWRITE_IF_EXISTS_OR_ADD
                  - header:
                      key: "X-Upstream-Host"
                      value: "%UPSTREAM_HOST%"
                    append_action: OVERWRITE_IF_EXISTS_OR_ADD

          http_filters:
          - name: envoy.filters.http.router
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router

Gateway API Integration

GatewayClass and Gateway

yaml

# GatewayClass definition
apiVersion: gateway.networking.k8s.io/v1
kind: GatewayClass
metadata:
  name: cilium
spec:
  controllerName: io.cilium/gateway-controller
---
# Gateway definition
apiVersion: gateway.networking.k8s.io/v1
kind: Gateway
metadata:
  name: api-gateway
  namespace: default
spec:
  gatewayClassName: cilium
  listeners:
  - name: http
    protocol: HTTP
    port: 80
    allowedRoutes:
      namespaces:
        from: Same

  - name: https
    protocol: HTTPS
    port: 443
    tls:
      mode: Terminate
      certificateRefs:
      - kind: Secret
        name: api-gateway-tls
    allowedRoutes:
      namespaces:
        from: Same

HTTPRoute

yaml

apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: api-routes
  namespace: default
spec:
  parentRefs:
  - name: api-gateway
    namespace: default

  hostnames:
  - "api.example.com"

  rules:
  # /users/* -> users-service
  - matches:
    - path:
        type: PathPrefix
        value: /users
    backendRefs:
    - name: users-service
      port: 80

  # /orders/* -> orders-service
  - matches:
    - path:
        type: PathPrefix
        value: /orders
    backendRefs:
    - name: orders-service
      port: 80

  # Header-based routing
  - matches:
    - path:
        type: PathPrefix
        value: /
      headers:
      - name: X-API-Version
        value: v2
    backendRefs:
    - name: api-v2
      port: 80

  # Weight-based splitting
  - matches:
    - path:
        type: PathPrefix
        value: /
    backendRefs:
    - name: api-stable
      port: 80
      weight: 90
    - name: api-canary
      port: 80
      weight: 10

HTTPRoute Advanced Features

yaml

apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: advanced-routes
  namespace: default
spec:
  parentRefs:
  - name: api-gateway

  rules:
  - matches:
    - path:
        type: PathPrefix
        value: /api

    # Request header modification
    filters:
    - type: RequestHeaderModifier
      requestHeaderModifier:
        add:
        - name: X-Request-ID
          value: "%REQ(X-REQUEST-ID)%"
        set:
        - name: X-Forwarded-Proto
          value: https
        remove:
        - X-Internal-Header

    # Response header modification
    - type: ResponseHeaderModifier
      responseHeaderModifier:
        add:
        - name: X-Frame-Options
          value: DENY
        - name: X-Content-Type-Options
          value: nosniff

    # URL rewrite
    - type: URLRewrite
      urlRewrite:
        path:
          type: ReplacePrefixMatch
          replacePrefixMatch: /v1

    backendRefs:
    - name: api-service
      port: 80

  # Redirect
  - matches:
    - path:
        type: Exact
        value: /old-endpoint
    filters:
    - type: RequestRedirect
      requestRedirect:
        scheme: https
        hostname: new.example.com
        path:
          type: ReplaceFullPath
          replaceFullPath: /new-endpoint
        statusCode: 301

Traffic Mirroring

yaml

apiVersion: cilium.io/v2
kind: CiliumEnvoyConfig
metadata:
  name: traffic-mirror
  namespace: default
spec:
  services:
  - name: production-service
    namespace: default

  backendServices:
  - name: production-backend
    namespace: default
  - name: shadow-backend
    namespace: default

  resources:
  - "@type": type.googleapis.com/envoy.config.listener.v3.Listener
    name: mirror-listener
    filter_chains:
    - filters:
      - name: envoy.filters.network.http_connection_manager
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
          stat_prefix: production-service
          route_config:
            name: mirror_routes
            virtual_hosts:
            - name: production
              domains: ["*"]
              routes:
              - match:
                  prefix: "/"
                route:
                  cluster: default/production-backend

                  # Traffic mirroring configuration
                  request_mirror_policies:
                  - cluster: default/shadow-backend
                    runtime_fraction:
                      default_value:
                        numerator: 100  # 100% mirroring
                        denominator: HUNDRED
                    trace_sampled: false

          http_filters:
          - name: envoy.filters.http.router
            typed_config:
              "@type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router

Next Steps

Security: Set up mTLS and L7 network policies
Observability: Monitor traffic with Hubble
Ingress & Gateway: External traffic management

Traffic Management

Security

Observability

Resilience

Advanced

Comparison Guide

ArgoCD

Metrics

Logging

Tracing

Alerting

Observability End-to-End Labs

Cilium Deep Dive

Calico Deep Dive

Istio Detailed Quiz

Linkerd Detailed Quiz

Cilium Service Mesh Detailed Quiz

ArgoCD Detailed Quiz

Metrics

Logging

Tracing

Alerting

Observability Labs

Cilium Service Mesh Traffic Management ​

Overview ​

Traffic Management Architecture ​

CiliumEnvoyConfig ​

Basic Structure ​

HTTP Routing ​

Path-based Routing ​

Header-based Routing ​

Method-based Routing ​

L7 Traffic Policies ​

CiliumNetworkPolicy L7 Rules ​

Various Protocol Support ​

Kafka L7 Policy ​

DNS L7 Policy ​

gRPC L7 Policy ​

Load Balancing ​

L4 Load Balancing (eBPF) ​

Maglev Hashing ​

L7 Load Balancing (Envoy) ​

Load Balancing Algorithm Options ​

Traffic Splitting (Canary Deployment) ​

Weight-based Traffic Splitting ​

Header-based Canary ​

Retry and Timeout ​

Retry Configuration ​

Timeout Configuration ​

Rate Limiting ​

Local Rate Limiting ​

Per-Route Rate Limiting ​

URL Rewriting and Header Manipulation ​

URL Rewriting ​

Header Manipulation ​

Gateway API Integration ​

GatewayClass and Gateway ​

HTTPRoute ​

HTTPRoute Advanced Features ​

Traffic Mirroring ​

Next Steps ​

References ​

Cilium Service Mesh Traffic Management

Overview

Traffic Management Architecture

CiliumEnvoyConfig

Basic Structure

HTTP Routing

Path-based Routing

Header-based Routing

Method-based Routing

L7 Traffic Policies

CiliumNetworkPolicy L7 Rules

Various Protocol Support

Kafka L7 Policy

DNS L7 Policy

gRPC L7 Policy

Load Balancing

L4 Load Balancing (eBPF)

Maglev Hashing

L7 Load Balancing (Envoy)

Load Balancing Algorithm Options

Traffic Splitting (Canary Deployment)

Weight-based Traffic Splitting

Header-based Canary

Retry and Timeout

Retry Configuration

Timeout Configuration

Rate Limiting

Local Rate Limiting

Per-Route Rate Limiting

URL Rewriting and Header Manipulation

URL Rewriting

Header Manipulation

Gateway API Integration

GatewayClass and Gateway

HTTPRoute

HTTPRoute Advanced Features

Traffic Mirroring

Next Steps

References