github.com/slene/docker@v1.8.0-rc1/docs/installation/centos.md (about)

     1  <!--[metadata]>
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     3  title = "Installation on CentOS"
     4  description = "Instructions for installing Docker on CentOS"
     5  keywords = ["Docker, Docker documentation, requirements, linux, centos, epel, docker.io,  docker-io"]
     6  [menu.main]
     7  parent = "smn_linux"
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     9  <![end-metadata]-->
    10  
    11  # CentOS
    12  
    13  Docker is supported on the following versions of CentOS:
    14  
    15  * CentOS 7.X 
    16  
    17  Installation on other binary compatible EL7 distributions such as Scientific
    18  Linux might succeed, but Docker does not test or support Docker on these
    19  distributions.
    20  
    21  This page instructs you to install using Docker-managed release packages and
    22  installation mechanisms. Using these packages ensures you get the latest release
    23  of Docker. If you wish to install using CentOS-managed packages, consult your
    24  CentOS documentation.
    25  
    26  ## Prerequisites
    27  
    28  Docker requires a 64-bit installation regardless of your CentOS version. Also,
    29  your kernel must be 3.10 at minimum, which CentOS 7 runs.
    30  
    31  To check your current kernel version, open a terminal and use `uname -r` to
    32  display your kernel version:
    33  
    34      $ uname -r 
    35      3.10.0-229.el7.x86_64
    36  
    37  Finally, is it recommended that you fully update your system. Please keep in
    38  mind that your system should be fully patched to fix any potential kernel bugs.
    39  Any reported kernel bugs may have already been fixed on the latest kernel
    40  packages.
    41  
    42  ## Install
    43  
    44  There are two ways to install Docker Engine.  You can use `curl` with the  `get.docker.com` site. This method runs an installation script which installs via the `yum` package manager. Or you can install with the `yum` package manager directly yourself.
    45  
    46  ### Install with the script
    47  
    48  
    49  1. Log into your machine as a user with `sudo` or `root` privileges.
    50  
    51  2. Make sure your existing yum packages are up-to-date.
    52  
    53  		$ sudo yum update
    54  		
    55  3. Run the Docker installation script.
    56  		
    57  		$ curl -sSL https://get.docker.com/ | sh
    58  		
    59  		This script adds the `docker.repo` repository and installs Docker.
    60  
    61  4. Start the Docker daemon.
    62  
    63  		$ sudo service docker start
    64  
    65  5. Verify `docker` is installed correctly by running a test image in a container.
    66  
    67  		$ sudo docker run hello-world
    68  		Unable to find image 'hello-world:latest' locally
    69  		latest: Pulling from hello-world
    70  		a8219747be10: Pull complete 
    71  		91c95931e552: Already exists 
    72  		hello-world:latest: The image you are pulling has been verified. Important: image verification is a tech preview feature and should not be relied on to provide security.
    73  		Digest: sha256:aa03e5d0d5553b4c3473e89c8619cf79df368babd1.7.1cf5daeb82aab55838d
    74  		Status: Downloaded newer image for hello-world:latest
    75  		Hello from Docker.
    76  		This message shows that your installation appears to be working correctly.
    77  
    78  		To generate this message, Docker took the following steps:
    79  		 1. The Docker client contacted the Docker daemon.
    80  		 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
    81  				(Assuming it was not already locally available.)
    82  		 3. The Docker daemon created a new container from that image which runs the
    83  				executable that produces the output you are currently reading.
    84  		 4. The Docker daemon streamed that output to the Docker client, which sent it
    85  				to your terminal.
    86  
    87  		To try something more ambitious, you can run an Ubuntu container with:
    88  		 $ docker run -it ubuntu bash
    89  
    90  		For more examples and ideas, visit:
    91  		 http://docs.docker.com/userguide/
    92  
    93  ### Install without the script
    94  
    95  1. Log into your machine as a user with `sudo` or `root` privileges.
    96  
    97  2. Make sure your existing yum packages are up-to-date.
    98  
    99          $ sudo yum update
   100      
   101  3. Add the yum repo yourself.
   102  
   103      For CentOS 7 run:
   104  
   105          $ cat >/etc/yum.repos.d/docker.repo <<-EOF
   106          [dockerrepo]
   107          name=Docker Repository
   108          baseurl=https://yum.dockerproject.org/repo/main/centos/7
   109          enabled=1
   110          gpgcheck=1
   111          gpgkey=https://yum.dockerproject.org/gpg
   112          EOF
   113  
   114  4. Install the Docker package.
   115  
   116          $ sudo yum install docker-engine
   117          
   118  5. Start the Docker daemon.
   119  
   120          $ sudo service docker start
   121  
   122  6. Verify `docker` is installed correctly by running a test image in a container.
   123  
   124          $ sudo docker run hello-world
   125   
   126  ## Create a docker group		
   127  
   128  The `docker` daemon binds to a Unix socket instead of a TCP port. By default
   129  that Unix socket is owned by the user `root` and other users can access it with
   130  `sudo`. For this reason, `docker` daemon always runs as the `root` user.
   131  
   132  To avoid having to use `sudo` when you use the `docker` command, create a Unix
   133  group called `docker` and add users to it. When the `docker` daemon starts, it
   134  makes the ownership of the Unix socket read/writable by the `docker` group.
   135  
   136  >**Warning**: The `docker` group is equivalent to the `root` user; For details
   137  >on how this impacts security in your system, see [*Docker Daemon Attack
   138  >Surface*](/articles/security/#docker-daemon-attack-surface) for details.
   139  
   140  To create the `docker` group and add your user:
   141  
   142  1. Log into Centos as a user with `sudo` privileges.
   143  
   144  2. Create the `docker` group and add your user.
   145  
   146      `sudo usermod -aG docker your_username`
   147  
   148  3. Log out and log back in.
   149  
   150      This ensures your user is running with the correct permissions.
   151  
   152  4. Verify your work by running `docker` without `sudo`.
   153  
   154  		$ docker run hello-world
   155   
   156  ## Start the docker daemon at boot
   157  
   158  To ensure Docker starts when you boot your system, do the following:
   159  
   160        $ sudo chkconfig docker on
   161  
   162  If you need to add an HTTP Proxy, set a different directory or partition for the
   163  Docker runtime files, or make other customizations, read our Systemd article to
   164  learn how to [customize your Systemd Docker daemon options](/articles/systemd/).
   165  
   166  
   167  ## Uninstall
   168  
   169  You can uninstall the Docker software with `yum`.  
   170  
   171  1. List the package you have installed.
   172  
   173  		$ yum list installed | grep docker
   174  		yum list installed | grep docker
   175  		docker-engine.x86_64                1.7.1-1.el7
   176  																																								 @/docker-engine-1.7.1-1.el7.x86_64.rpm
   177  
   178  2. Remove the package.
   179  
   180  		$ sudo yum -y remove docker-engine.x86_64 
   181  
   182  	This command does not remove images, containers, volumes, or user-created
   183  	configuration files on your host. 
   184  
   185  3. To delete all images, containers, and volumes, run the following command:
   186  
   187  		$ rm -rf /var/lib/docker
   188  
   189  4. Locate and delete any user-created configuration files.