docker构建微服务 启动web容器

一、查看docker客户端命令

docker.png

1. 通过docker COMMAND --help 更深入的了解指定的docker命令的用法
   例如：

[root@localhost ~]# docker stats --help

Usage: docker stats [OPTIONS] CONTAINER [CONTAINER...]

Display a live stream of one or more containers' resource usage statistics

  --help=false         Print usage
  --no-stream=false    Disable streaming stats and only pull the first result

二、运行一个web应用

在docker容器中运行一个Python Flask应用

1. 载入镜像

[root@localhost ~]# docker pull training/webapp
latest: Pulling from training/webapp
e9e06b06e14c: Pull complete 
a82efea989f9: Pull complete 
37bea4ee0c81: Pull complete 
07f8e8c5e660: Pull complete 
23f0158a1fbe: Pull complete 
0a4852b23749: Pull complete 
7d0ff9745632: Pull complete 
99b0d955e85d: Pull complete 
33e109f2ff13: Pull complete 
cc06fd877d54: Pull complete 
b1ae241d644a: Pull complete 
b37deb56df95: Pull complete 
02a8815912ca: Already exists 
Digest: sha256:06e9c1983bd6d5db5fba376ccd63bfa529e8d02f23d5079b8f74a616308fb11d
Status: Downloaded newer image for training/webapp:latest

2. 启动应用程序，并查看正在运行的容器

[root@localhost ~]# docker run -d -P training/webapp python app.py
2b939c4ffe3a2f6508c2fca9f92e2ef78300028f2643673535d377a8d6c6c851
[root@localhost ~]# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS                     NAMES
2b939c4ffe3a        training/webapp     "python app.py"     6 seconds ago       Up 5 seconds        0.0.0.0:32769->5000/tcp   happy_poitras  

多了PORTS列，显示端口映射：0.0.0.0:32769->5000/tcp，此时访问IP+端口（32769）可以看到web程序已经正常运行起来了

web.png

3. 查看web容器日志:docker logs -f ID/NAME

[root@localhost ~]# docker logs -f 2b939c4ffe3a
 * Running on http://0.0.0.0:5000/ (Press CTRL+C to quit)
192.168.72.173 - - [07/Mar/2018 06:37:23] "GET / HTTP/1.1" 200 -
192.168.72.173 - - [07/Mar/2018 06:37:24] "GET /favicon.ico HTTP/1.1" 404 -
192.168.72.173 - - [07/Mar/2018 06:37:36] "GET / HTTP/1.1" 200 -
192.168.72.173 - - [07/Mar/2018 06:46:24] "GET / HTTP/1.1" 200 -

三、停止web容器

命令：docker start ID/NAME

docker stop 2b939c4ffe3a

四、移除web容器

命令：docker rm ID/NAME

docker rm 2b939c4ffe3a

移除容器时必须先停止容器，否则会报错

[root@localhost ~]# docker rm 2b939c4ffe3a
Error response from daemon: Cannot destroy container 2b939c4ffe3a: Conflict, You cannot remove a running container. Stop the container before attempting removal or use -f
Error: failed to remove containers: [2b939c4ffe3a]

移除容器后，使用docker info查看，可以发现Containers 数量减少

[root@localhost ~]# docker info
Containers: 8  #数量减少了一个
Images: 16