3.3.1 Container入门
使用info命令检查docker安装程序是否正常运行:
# 检查是否安装好docker
$ docker info
如果提示如下信息: command not found 或者 类似于/var/lib/docker/repositories: permission denied 可能安装有问题或者尝试在前面加上sudo。
此外,基于docker系统配置,命令行前面应该加上sudo,来确保正常执行命令,并且此时系统会为Administrar创建一个名叫docker的Unix 用户组来让其他用户加入该组。
下载一个已经制作好的镜像
$ docker pull ubuntu
这条命令会从Docker Hub上搜索ubuntu镜像,然后下载到本里镜像缓存中去。
Note:When the image is successfully downloaded, you see a 12 character hash 539c0211cd76: Download complete which is the short form of the image ID. These short image IDs are the first 12 characters of the full image ID - which can be found using docker inspect or docker images --no-trunc=true.
创建一个带有交互窗口的container
$ docker run -i -t ubuntu /bin/bash
—i参数表示启动了一个可以交互的容器,—t参数表示创建了一个附带标准输入和输出的pseudo-TTY窗口
如果想要退出tty窗口,使用 Ctrl-p + Ctrl-q指令,容器将会退出并且会持续保持一个停止的状态。如果想查看所有状态的容器,可以使用docker ps -a 指令。
绑定容器到另外一个主机/端口或者一个Unix Socket
Warning: Changing the default docker daemon binding to a TCP port or Unix docker user group will increase your security risks by allowing non-root users to gain root access on the host. Make sure you control access to docker. If you are binding to a TCP port, anyone with access to that port has full Docker access; so it is not advisable on an open network.
使用 -H 能够让Docker deamon监听特殊的IP和端口。默认情况下,它将监听unix:///var/run/docker.sock以仅允许root进行本地连接。你可以将它设置为0.0.0.0:2375或者是指定的主机IP以供所有人连接,但是并不建议这么做,因为这将使某些无聊的人也获得deamon运行主机root的访问权限。
类似的,Docker客户端也可以使用 —H 连接一个指定端口
-H 使用以下格式来分配主机和端口 :
tcp://[host][:port][path] or unix://path
例如:
- tcp://host:2375 -> TCP connection on host:2375
- tcp://host:2375/path -> TCP connection on host:2375 and prepend path to all requests
- unix://path/to/socket -> Unix socket located at path/to/socket
当—H参数为空时,将被默认认为没有—H参数传进来
-H also accepts short form for TCP bindings:
host[:port] or :port
Docker以daemon模式运行:
$ sudo <path to>/docker daemon -H 0.0.0.0:5555 &
下载一个ubuntu镜像:
$ docker -H :5555 pull ubuntu
如果你想同时监听TCP和Unix Socket 你可以添加多个 -H
# Run docker in daemon mode
$ sudo <path to>/docker daemon -H tcp://127.0.0.1:2375 -H unix:///var/run/docker.sock &
# Download an ubuntu image, use default Unix socket
$ docker pull ubuntu
# OR use the TCP port
$ docker -H tcp://127.0.0.1:2375 pull ubuntu
起一个持续工作的进程
# Start a very useful long-running process
$ JOB=$(docker run -d ubuntu /bin/sh -c "while true; do echo Hello world; sleep 1; done")
# Collect the output of the job so far
$ docker logs $JOB
# Kill the job
$ docker kill $JOB
监听容器
$ docker ps # Lists only running containers
$ docker ps -a # Lists all containers
管理容器
# Start a new container
$ JOB=$(docker run -d ubuntu /bin/sh -c "while true; do echo Hello world; sleep 1; done")
# Stop the container
$ docker stop $JOB
# Start the container
$ docker start $JOB
# Restart the container
$ docker restart $JOB
# SIGKILL a container
$ docker kill $JOB
# Remove a container
$ docker stop $JOB # Container must be stopped to remove it
$ docker rm $JOB
在一个TCP端口上绑定一个服务
# Bind port 4444 of this container, and tell netcat to listen on it
$ JOB=$(docker run -d -p 4444 ubuntu:12.10 /bin/nc -l 4444)
# Which public port is NATed to my container?
$ PORT=$(docker port $JOB 4444 | awk -F: '{ print $2 }')
# Connect to the public port
$ echo hello world | nc 127.0.0.1 $PORT
# Verify that the network connection worked
$ echo "Daemon received: $(docker logs $JOB)"
提交(保存)一个容器的状态到一个镜像文件中
当提交(commit)容器时,docker仅保存源镜像与当前镜像的差异,如果想列出镜像,请使用docker images指令
# Commit your container to a new named image
$ docker commit <container> <some_name>
# List your images
$ docker images