(OK) dnf——install docker on Fedora23

https://docs.docker.com/engine/installation/linux/fedora/

Fedora

Docker is supported on Fedora version 22 and 23. This page instructs you to installusing Docker-managed release packages and installation mechanisms. Using thesepackages ensures you get the latest release of Docker. If you wish to installusing Fedora-managed packages, consult your Fedora release documentation forinformation on Fedora’s Docker support.

Prerequisites

Docker requires a 64-bit installation regardless of your Fedora version. Also, your kernel must be 3.10 at minimum. To check your current kernelversion, open a terminal and use uname -r to display your kernel version:

$ uname -r
3.19.5-100.fc21.x86_64

If your kernel is at a older version, you must update it.

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

Install

There are two ways to install Docker Engine. You can install with the dnf package manager. Or you can use curl with the get.docker.com site. This second method runs an installation script which also installs via the dnf package manager.

Install with DNF

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

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

   $ sudo dnf update
   

3. Add the yum repo yourself.

   $ sudo tee /etc/yum.repos.d/docker.repo <<-'EOF'
   [dockerrepo]
   name=Docker Repository
   baseurl=https://yum.dockerproject.org/repo/main/fedora/$releasever/
   enabled=1
   gpgcheck=1
   gpgkey=https://yum.dockerproject.org/gpg
   EOF
   

4. Install the Docker package.

   $ sudo dnf install docker-engine
   

5. Start the Docker daemon.

   $ sudo systemctl start docker
   

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

   $ sudo docker run hello-world
   Unable to find image 'hello-world:latest' locally
   latest: Pulling from hello-world
   a8219747be10: Pull complete
   91c95931e552: Already exists
   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.
   Digest: sha256:aa03e5d0d5553b4c3473e89c8619cf79df368babd1.7.1cf5daeb82aab55838d
   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.
       (Assuming it was not already locally available.)
    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
   
   For more examples and ideas, visit:
    http://docs.docker.com/userguide/
   

Install with the script

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

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

   $ sudo dnf update
   

3. Run the Docker installation script.

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

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

4. Start the Docker daemon.

   $ sudo systemctl start docker
   

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

   $ sudo docker run hello-world
   

Create a docker group

The docker daemon binds to a Unix socket instead of a TCP port. By defaultthat Unix socket is owned by the user root and other users can access it withsudo. 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 Unixgroup called docker and add users to it. When the docker daemon starts, itmakes the ownership of the Unix socket read/writable by the docker group.

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

To create the docker group and add your user:

1. Log into your system as a user with sudo privileges.

2. Create the docker group.

   sudo groupadd docker

3. Add your user to docker group.

   sudo usermod -aG docker your_username

4. Log out and log back in.

   This ensures your user is running with the correct permissions.

5. Verify your work by running docker without sudo.

   $ docker run hello-world
   

Start the docker daemon at boot

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

$ sudo systemctl enable docker

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

Running Docker with a manually-defined network

If you manually configure your network using systemd-network with systemd version 219 or higher, containers you start with Docker may be unable to access your network.Beginning with version 220, the forwarding setting for a given network (net.ipv4.conf.<interface>.forwarding) defaults to off. This setting prevents IP forwarding. It also conflicts with Docker which enables the net.ipv4.conf.all.forwarding setting within a container.

To work around this, edit the <interface>.network file in/usr/lib/systemd/network/ on your Docker host (ex: /usr/lib/systemd/network/80-container-host0.network) add the following block:

[Network]
...
IPForward=kernel
# OR
IPForward=true
...

This configuration allows IP forwarding from the container as expected.

Uninstall

You can uninstall the Docker software with dnf.

1. List the package you have installed.

   $ dnf list installed | grep docker dnf list installed | grep docker
   docker-engine.x86_64     1.7.1-0.1.fc21 @/docker-engine-1.7.1-0.1.fc21.el7.x86_64
   

2. Remove the package.

   $ sudo dnf -y remove docker-engine.x86_64
   

   This command does not remove images, containers, volumes, or user-createdconfiguration 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.