docker三剑客：docker-compose做负载均衡

一、认识compose

二、compose实践

1. 使用 docker-compose做负载均衡集群
   docker-compose官方文档https://docs.docker.com/compose/

[[e-mail] ~]#mkdir compose
[[e-mail] ~]#cd compose/
[[e-mail] ~/compose]# touch docker-compose.yml  #使用 docker-compose做负载均衡集群
[[e-mail] ~/compose]#cat docker-compose.yml 
version: "3.7"
services:

  web1:
    image: nginx
    volumes:
      - ./web1:/usr/share/nginx/html
    networks:
      - haproxy-net
  web2:
    image: nginx
    volumes:
      - ./web2:/usr/share/nginx/html 
    networks:
      - haproxy-net
  haproxy:
    image: haproxy
    volumes:
      - ./haproxy/haproxy.cfg:/usr/local/etc/haproxy/haproxy.cfg:ro
    ports:
      - "80:80"
    networks:
      - haproxy-net

networks:
  haproxy-net:

[[e-mail] ~/compose]#mkdir web1
[[e-mail] ~/compose]#mkdir web2
[[e-mail] ~/compose]#mkdir haproxy
[[e-mail] ~/compose]#cd haproxy/

[[e-mail] ~/compose/haproxy]#yum install haproxy
[[e-mail] ~/compose/haproxy]#mv /etc/haproxy/haproxy.cfg .
[[e-mail] ~/compose/haproxy]#ls
haproxy.cfg

[[e-mail] ~/compose/haproxy]#vim haproxy.cfg
    log         127.0.0.1 local2

    pidfile     /var/run/haproxy.pid
    maxconn     4000
    daemon

    # turn on stats unix socket

#---------------------------------------------------------------------
# common defaults that all the 'listen' and 'backend' sections will
# use if not designated in their block
#---------------------------------------------------------------------
defaults
    mode                    http
    log                     global
    option                  httplog
    option                  dontlognull
    option http-server-close
    option forwardfor       except 127.0.0.0/8
    option                  redispatch
    retries                 3
    timeout http-request    10s
    timeout queue           1m
    timeout connect         10s
    timeout client          1m
    timeout server          1m
    timeout http-keep-alive 10s
    timeout check           10s
    maxconn                 3000
    
    stats uri /status
#---------------------------------------------------------------------
# main frontend which proxys to the backends
#---------------------------------------------------------------------
frontend  main 
    bind *:80
    default_backend             app

backend app
    balance     roundrobin
    server  app1 web1:80 check
    server  app2 web2:80 check
[[e-mail] ~/compose/haproxy]#docker-compose up

在web1和web2中写入index.html
[[e-mail] ~/compose]#cat web1/index.html 
hello web1!!!
[[e-mail] ~/compose]#cat web2/index.html 
hello web2

[[e-mail] ~/compose]#docker-compose start
Starting web1    ... done
Starting web2    ... done
Starting haproxy ... done

测试：


2. 共享卷

[[e-mail] ~/compose]#docker-compose stop
Stopping compose_haproxy_1 ... done
Stopping compose_web1_1    ... done
Stopping compose_web2_1    ... done

[[e-mail] ~/compose]#cat docker-compose.yml 
version: "3.7"
services:

  web1:
    image: nginx
    volumes:
      - webdata:/usr/share/nginx/html
    networks:
      - haproxy-net
  web2:
    image: nginx
    volumes:
      - webdata:/usr/share/nginx/html 
    networks:
      - haproxy-net
  haproxy:
    image: haproxy
    volumes:
      - ./haproxy/haproxy.cfg:/usr/local/etc/haproxy/haproxy.cfg:ro
    ports:
      - "80:80"
    networks:
      - haproxy-net

networks:
  haproxy-net:
   
volumes:
  webdata:

[[e-mail] ~/compose]#docker-compose up -d # 打入后台
[[e-mail] ~/compose]#docker-compose logs # 查看日志

测试：


健康检查：停掉web2

[[e-mail] ~/compose]#docker stop compose_web2_1
compose_web2_1

[[e-mail] ~/compose]#docker start compose_web2_1
compose_web2_1

三、总结