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【云原生 | Kubernetes 系列】--Envoy Tcp请求静态配置

news 来源：原创 2024/5/14 2:57:15

Envoy Tcp请求静态配置

1 准备工作

准备工作包括:

docker-compose环境准备
yaml及docker-compse配置文件获取(来自github/ikubernetes)

# apt install docker-compose -y
# docker pull envoyproxy/envoy-alpine:v1.21.5
# mkdir /apps/envoy -p
# cd /apps/envoy
# git clone https://github.com/ikubernetes/servicemesh_in_practise.git
# cd servicemesh_in_practise/
# ls
admin-interface     eds-filesystem  envoy.echo               http-egress   LICENSE                 security  tls-front-proxy
cds-eds-filesystem  eds-grpc        front-proxy              http-ingress  monitoring-and-tracing  tcpproxy
cluster-manager     eds-rest        http-connection-manager  lds-cds-grpc  README.md               template
# git checkout develop
Branch 'develop' set up to track remote branch 'develop' from 'origin'.
Switched to a new branch 'develop'
# ls
Cluster-Manager        Envoy-Basics  HTTP-Connection-Manager  Monitoring-and-Tracing  Security
Dynamic-Configuration  Envoy-Mesh    LICENSE                  README.md               template
# cd Envoy-Basics/tcp-front-proxy/

2 docker-compose配置

docker-compose定义了3个容器

业务容器webserver01 IP地址172.31.1.11
业务容器webserver02 IP地址172.31.1.12
envoy容器 IP地址172.31.1.2
定义envoymesh的网桥

/apps/envoy/servicemesh_in_practise/Envoy-Basics/tcp-front-proxy# cat docker-compose.yaml 
version: '3.3'
services:
  envoy:
    image: envoyproxy/envoy-alpine:v1.21.5
    volumes:
    - ./envoy.yaml:/etc/envoy/envoy.yaml
    networks:
      envoymesh:
        ipv4_address: 172.31.1.2
        aliases:
        - front-proxy
    depends_on:
    - webserver01
    - webserver02

  webserver01:
    image: ikubernetes/demoapp:v1.0
    environment:
      - PORT=8080
    hostname: webserver01
    networks:
      envoymesh:
        ipv4_address: 172.31.1.11
        aliases:
        - webserver01

  webserver02:
    image: ikubernetes/demoapp:v1.0
    environment:
      - PORT=8080
    hostname: webserver02
    networks:
      envoymesh:
        ipv4_address: 172.31.1.12
        aliases:
        - webserver02

networks:
  envoymesh:
    driver: bridge
    ipam:
      config:
        - subnet: 172.31.1.0/24

3 envoy.yaml配置

envoy.yaml中定义:

使用的是静态配置static_resources
监听器监听 0.0.0.0:80 端口
监听器接收到请求转发给filter_chains,filter_chains串联了tcp_proxy过滤器对请求进行解码,代理给local_cluster
clusters中定义了local_cluster,其中包含2个Endpoint,172.31.1.11:8080 和172.31.1.12:8080

static_resources:
  listeners:
    name: listener_0
    address:
      socket_address: { address: 0.0.0.0, port_value: 80 }
    filter_chains:
    - filters:
      - name: envoy.tcp_proxy
        typed_config:
          "@type": type.googleapis.com/envoy.extensions.filters.network.tcp_proxy.v3.TcpProxy
          stat_prefix: tcp
          cluster: local_cluster

  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: 172.31.1.11, port_value: 8080 }
        - endpoint:
            address:
              socket_address: { address: 172.31.1.12, port_value: 8080 }

4 部署并测试访问

启动docker-compose后,客户端访问172.31.1.2查看转发效果

# docker-compose up
## 客户端上执行
# curl 172.31.1.2
iKubernetes demoapp v1.0 !! ClientIP: 172.31.1.2, ServerName: webserver01, ServerIP: 172.31.1.11!
# curl 172.31.1.2
iKubernetes demoapp v1.0 !! ClientIP: 172.31.1.2, ServerName: webserver02, ServerIP: 172.31.1.12!
# curl 172.31.1.2
iKubernetes demoapp v1.0 !! ClientIP: 172.31.1.2, ServerName: webserver02, ServerIP: 172.31.1.12!
# curl 172.31.1.2
iKubernetes demoapp v1.0 !! ClientIP: 172.31.1.2, ServerName: webserver01, ServerIP: 172.31.1.11!
## docker-compose服务器上可以看到请求的记录
envoy_1        | [2022-09-23 06:36:33.256][1][info][main] [source/server/server.cc:868] starting main dispatch loop
webserver01_1  | 172.31.1.2 - - [23/Sep/2022 06:38:19] "GET / HTTP/1.1" 200 -
webserver02_1  | 172.31.1.2 - - [23/Sep/2022 06:38:20] "GET / HTTP/1.1" 200 -
webserver02_1  | 172.31.1.2 - - [23/Sep/2022 06:38:21] "GET / HTTP/1.1" 200 -
webserver01_1  | 172.31.1.2 - - [23/Sep/2022 06:38:21] "GET / HTTP/1.1" 200 -
## 测试完清理环境
# docker-compose down

5 访问流程梳理

当客户端访问172.31.1.2:80(docker-compose中的envoy容器),请求被转发到front-proxy的Listener上的80端口(listener中socket_address定义)
由filter chains定义的tcp_proxy过滤器对请求进行解码,将传输层报文通过tcp_proxy(typed_config中定义)解码到Clusters中的local_cluster
Cluster使用轮询算法将请求转发到后端的Endpoint(clusters中socket_address字段定义)上.

请添加图片描述