CentOS7上安装docker

前置需求

Docker requires a 64-bit installation regardless of your CentOS version. Also, your kernel must be 3.10 at minimum, which CentOS 7 runs.

 

To check your current kernel version, open a terminal and use uname -r to display your kernel version:

 

$ uname -r
3.10.0-229.el7.x86_64

 Finally, is it recommended that you fully update your system. Please keep in mind that your system should be fully patched to fix any potential kernel bugs. Any reported kernel bugs may have already been fixed on the latest kernel packages.

 

安装

使用yum安装

1. Log into your machine as a user with sudo or root privileges.

2. Make sure your existing yum packages are up-to-date.

   $ sudo yum update
   

3. Add the yum repo.

   $ cat >/etc/yum.repos.d/docker.repo <<-EOF
   [dockerrepo]
   name=Docker Repository
   baseurl=https://yum.dockerproject.org/repo/main/centos/7
   enabled=1
   gpgcheck=1
   gpgkey=https://yum.dockerproject.org/gpg
   EOF
   

4. Install the Docker package.

   $ sudo yum install docker-engine
   

5. Start the Docker daemon.

   [root@localhost yum.repos.d]# service docker start 
   Redirecting to /bin/systemctl start  docker.service
   [root@localhost yum.repos.d]# systemctl status docker.service 
   docker.service - Docker Application Container Engine
      Loaded: loaded (/usr/lib/systemd/system/docker.service; disabled)
      Active: active (running) since Mon 2015-11-23 12:02:49 CST; 38s ago
        Docs: https://docs.docker.com
    Main PID: 24604 (docker)
      CGroup: /system.slice/docker.service
              └─24604 /usr/bin/docker daemon -H fd://
   
   Nov 23 12:02:42 localhost docker[24604]: time="2015-11-23T12:02:42.525348139+08:00"...k"
   Nov 23 12:02:43 localhost docker[24604]: time="2015-11-23T12:02:43.186687088+08:00"...."
   Nov 23 12:02:48 localhost docker[24604]: time="2015-11-23T12:02:48.445011858+08:00"...e"
   Nov 23 12:02:48 localhost docker[24604]: time="2015-11-23T12:02:48.707777823+08:00"...s"
   Nov 23 12:02:49 localhost docker[24604]: time="2015-11-23T12:02:49.199709207+08:00"...."
   Nov 23 12:02:49 localhost docker[24604]: time="2015-11-23T12:02:49.200088699+08:00"...."
   Nov 23 12:02:49 localhost docker[24604]: time="2015-11-23T12:02:49.200255413+08:00"...n"
   Nov 23 12:02:49 localhost docker[24604]: time="2015-11-23T12:02:49.200283835+08:00"....1
   Nov 23 12:02:49 localhost systemd[1]: Started Docker Application Container Engine.
   Hint: Some lines were ellipsized, use -l to show in full.
   

    

6. Verify docker is installed correctly by running a test image in a container.

[linus_dev@localhost repo]$ docker run hello-world
Cannot connect to the Docker daemon. Is the docker daemon running on this host?
[root@localhost yum.repos.d]# sudo docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
b901d36b6f2f: Verifying Checksum 
0a6ba66e537a: Verifying Checksum 
Pulling repository docker.io/library/hello-world
975b84d108f1: Download complete 
3f12c794407e: Download complete 
Status: Downloaded newer image for hello-world:latest
docker.io/library/hello-world: this image was pulled from a legacy registry.  Important: This registry version will not be supported in future versions of docker.

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/userguide/

 使用脚本安装

1. Log into your machine as a user with sudo or root privileges.

2. Make sure your existing yum packages are up-to-date.

   $ sudo yum update
   

3. Run the Docker installation script.

   $ curl -sSL https://get.docker.com/ | sh
   

   This script adds the docker.repo repository and installs Docker.

4. Start the Docker daemon.

   $ sudo service docker start
   

5. Verify docker is installed correctly by running a test image in a container.

   $ sudo docker run hello-world
   

创建一个docker组

The docker daemon binds to a Unix socket instead of a TCP port. By default that Unix socket is owned by the user root and other users can access it with sudo. For this reason, docker daemon always runs as the root user.

To avoid having to use sudo when you use the docker command, create a Unix group called docker and add users to it. When the docker daemon starts, it makes the ownership of the Unix socket read/writable by the docker group.

Warning: The docker group is equivalent to the root user; For details on how this impacts security in your system, see Docker Daemon Attack Surface for details.

To create the docker group and add your user:

1. Log into Centos as a user with sudo privileges.

2. Create the docker group and add your user.

   sudo usermod -aG docker your_username

3. Log out and log back in.

   This ensures your user is running with the correct permissions.

4. Verify your work by running docker without sudo.

   $ docker run hello-world
   

启动时默认启动docker

To ensure Docker starts when you boot your system, do the following:

  $ sudo chkconfig docker on

If you need to add an HTTP Proxy, set a different directory or partition for the Docker runtime files, or make other customizations, read our Systemd article to learn how to customize your Systemd Docker daemon options.

卸载

You can uninstall the Docker software with yum.

1. List the package you have installed.

   $ yum list installed | grep docker
   yum list installed | grep docker
   docker-engine.x86_64   1.7.1-1.el7 @/docker-engine-1.7.1-1.el7.x86_64.rpm
   

2. Remove the package.

   $ sudo yum -y remove docker-engine.x86_64
   

   This command does not remove images, containers, volumes, or user-created configuration files on your host.

3. To delete all images, containers, and volumes, run the following command:

   $ rm -rf /var/lib/docker
   

4. Locate and delete any user-created configuration files.