envoy算法-LEAST_REQUEST

root@user:/opt/servicemesh_in_practise/Cluster-Manager/least-requests# cat front-envoy.yaml 
admin:
  profile_path: /tmp/envoy.prof
  access_log_path: /tmp/admin_access.log
  address:
    socket_address: { address: 0.0.0.0, port_value: 9901 }

static_resources:
  listeners:
  - name: listener_0
    address:
      socket_address: { address: 0.0.0.0, port_value: 80 }
    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: ingress_http
          codec_type: AUTO
          route_config:
            name: local_route
            virtual_hosts:
            - name: webservice
              domains: ["*"]
              routes:
              - match: { prefix: "/" }
                route: { cluster: web_cluster_01 }
          http_filters:
          - name: envoy.filters.http.router

  clusters:
  - name: web_cluster_01
    connect_timeout: 0.25s
    type: STRICT_DNS
    lb_policy: LEAST_REQUEST
    load_assignment:
      cluster_name: web_cluster_01
      endpoints:
      - lb_endpoints:
        - endpoint:
            address:
              socket_address:
                address: red
                port_value: 80
          load_balancing_weight: 1
        - endpoint:
            address:
              socket_address:
                address: blue
                port_value: 80
          load_balancing_weight: 3
        - endpoint:
            address:
              socket_address:
                address: green
                port_value: 80
          load_balancing_weight: 5

root@user:/opt/servicemesh_in_practise/Cluster-Manager/least-requests# cat envoy-sidecar-proxy.yaml 

admin:
  profile_path: /tmp/envoy.prof
  access_log_path: /tmp/admin_access.log
  address:
    socket_address:
       address: 0.0.0.0
       port_value: 9901

static_resources:
  listeners:
  - name: listener_0
    address:
      socket_address: { address: 0.0.0.0, port_value: 80 }
    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: ingress_http
          codec_type: AUTO
          route_config:
            name: local_route
            virtual_hosts:
            - name: local_service 
              domains: ["*"]
              routes:
              - match: { prefix: "/" }
                route: { cluster: local_cluster }
          http_filters:
          - name: envoy.filters.http.router

  clusters:
  - name: local_cluster
    connect_timeout: 0.25s
    type: STATIC
    lb_policy: ROUND_ROBIN
    load_assignment:
      cluster_name: local_cluster
      endpoints:
      - lb_endpoints:
        - endpoint:
            address:
              socket_address: { address: 127.0.0.1, port_value: 8080 }

root@user:/opt/servicemesh_in_practise/Cluster-Manager/least-requests# cat docker-compose.yaml 

version: '3.3'

services:
  envoy:
    image: envoyproxy/envoy-alpine:v1.18-latest
    volumes:
    - ./front-envoy.yaml:/etc/envoy/envoy.yaml
    networks:
      envoymesh:
        ipv4_address: 172.31.22.2
        aliases:
        - front-proxy
    depends_on:
    - webserver01-sidecar
    - webserver02-sidecar
    - webserver03-sidecar

  webserver01-sidecar:
    image: envoyproxy/envoy-alpine:v1.18-latest
    volumes:
    - ./envoy-sidecar-proxy.yaml:/etc/envoy/envoy.yaml
    hostname: red
    networks:
      envoymesh:
        ipv4_address: 172.31.22.11
        aliases:
        - myservice
        - red

  webserver01:
    image: ikubernetes/demoapp:v1.0
    environment:
      - PORT=8080
      - HOST=127.0.0.1
    network_mode: "service:webserver01-sidecar"
    depends_on:
    - webserver01-sidecar

  webserver02-sidecar:
    image: envoyproxy/envoy-alpine:v1.18-latest
    volumes:
    - ./envoy-sidecar-proxy.yaml:/etc/envoy/envoy.yaml
    hostname: blue
    networks:
      envoymesh:
        ipv4_address: 172.31.22.12
        aliases:
        - myservice
        - blue

  webserver02:
    image: ikubernetes/demoapp:v1.0
    environment:
      - PORT=8080
      - HOST=127.0.0.1
    network_mode: "service:webserver02-sidecar"
    depends_on:
    - webserver02-sidecar

  webserver03-sidecar:
    image: envoyproxy/envoy-alpine:v1.18-latest
    volumes:
    - ./envoy-sidecar-proxy.yaml:/etc/envoy/envoy.yaml
    hostname: green
    networks:
      envoymesh:
        ipv4_address: 172.31.22.13
        aliases:
        - myservice
        - green

  webserver03:
    image: ikubernetes/demoapp:v1.0
    environment:
      - PORT=8080
      - HOST=127.0.0.1
    network_mode: "service:webserver03-sidecar"
    depends_on:
    - webserver03-sidecar

networks:
  envoymesh:
    driver: bridge
    ipam:
      config:
        - subnet: 172.31.22.0/24

root@user:/opt/servicemesh_in_practise/Cluster-Manager/least-requests# cat send-request.sh 
#!/bin/bash
declare -i red=0
declare -i blue=0
declare -i green=0

#interval="0.1"
counts=300

echo "Send 300 requests, and print the result. This will take a while."
echo ""
echo "Weight of all endpoints:"
echo "Red:Blue:Green = 1:3:5"

for ((i=1; i<=${counts}; i++)); do
    if curl -s http://$1/hostname | grep "red" &> /dev/null; then
        # $1 is the host address of the front-envoy.
        red=$[$red+1]
    elif curl -s http://$1/hostname | grep "blue" &> /dev/null; then
        blue=$[$blue+1]
    else
        green=$[$green+1]
    fi
#    sleep $interval
done

echo ""
echo "Response from:"
echo "Red:Blue:Green = $red:$blue:$green"

root@user:/opt/servicemesh_in_practise/Cluster-Manager/least-requests# ./send-request.sh 172.31.22.2
Send 300 requests, and print the result. This will take a while.

Weight of all endpoints:
Red:Blue:Green = 1:3:5

Response from:
Red:Blue:Green = 34:79:187