四十九、Docker Compose-水平扩展与负载均衡

源码下载 本节源码

环境清理

删除所有容器和镜像

$ docker container rm -f $(docker container ps -aq)
$ docker system prune -a -f

启动

下载源码，进入源码目录

$ docker-compose pull
$ docker-compose build
$ docker-compose up -d
Creating network "compose-scale-example_default" with the default driver
Creating compose-scale-example_flask_1        ... done
Creating compose-scale-example_client_1       ... done
Creating compose-scale-example_redis-server_1 ... done
$ docker-compose ps
                Name                              Command               State    Ports
----------------------------------------------------------------------------------------
compose-scale-example_client_1         sh -c while true; do sleep ...   Up
compose-scale-example_flask_1          flask run -h 0.0.0.0             Up      5000/tcp
compose-scale-example_redis-server_1   docker-entrypoint.sh redis ...   Up      6379/tcp

水平扩展 scale

$ docker-compose up -d --scale flask=3
compose-scale-example_client_1 is up-to-date
compose-scale-example_redis-server_1 is up-to-date
Creating compose-scale-example_flask_2 ... done
Creating compose-scale-example_flask_3 ... done
$ docker-compose ps
                Name                              Command               State    Ports
----------------------------------------------------------------------------------------
compose-scale-example_client_1         sh -c while true; do sleep ...   Up
compose-scale-example_flask_1          flask run -h 0.0.0.0             Up      5000/tcp
compose-scale-example_flask_2          flask run -h 0.0.0.0             Up      5000/tcp
compose-scale-example_flask_3          flask run -h 0.0.0.0             Up      5000/tcp
compose-scale-example_redis-server_1   docker-entrypoint.sh redis ...   Up      6379/tcp

负载均衡

• 进入其中一个容器ping flask会进行DNS解析的负载均衡，每次取第一个实例（ip）返回

  
  

• 访问5000端口运行程序也有负载均衡

  
  

添加 nginx

源码下载 源码更新