1. Docker 引擎 - 安装并运行hello-world

• 在docker上运行hello-world

[root@localhost ~]# docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
c04b14da8d14: Pull complete
Digest: sha256:0256e8a36e2070f7bf2d0b0763dbabdd67798512411de4cdcf9431a1feb60fd9
Status: Downloaded newer image for hello-world:latest

Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker Hub account:
 https://hub.docker.com

For more examples and ideas, visit:
 https://docs.docker.com/engine/userguide/

该命令docker run hello-world中, hello-world是镜像名, 根据打印提示, 镜像hello-world在本地并不存在, 所以会在远程镜像仓库中寻找, 如果找到会下载并执行. latest指镜像的标签(tag), 如果没有指定会默认为latest.

• docker ps 命令查询所有容器

[root@localhost ~]# docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                     PORTS               NAMES
cd440a1acaad        hello-world         "/hello"            8 minutes ago       Exited (0) 7 minutes ago                       goofy_shaw

docker ps 只列出正在运行中的容器