Install the docker tutorial under Centos

  • 2020-05-15 02:40:00
  • OfStack

Install via yum

Requires permission to root or to sudo

The yum package is updated to the latest


$ sudo yum update

Add the Docker yum source


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

Install Docker package


$ sudo yum install docker-engine

Start the Docker daemon


$ sudo service docker start

Verify that Docker is installed correctly by running a container with a test image


$ 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/

Script installation

You need permission to root or to sudo

The yum package is updated to the latest


$ sudo yum update

Run the Docker installation script


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

This script adds the docker.repo repository and installs Docker

Start the Docker daemon


$ sudo service docker start

Verify that Docker is installed correctly by running a container with a test image


$ sudo docker run hello-world

Create one Docker user group

The docker daemon is bound to Unix socket instead of TCP port. By default, Unix socket belongs to root users and users with sudo permissions. For this reason, the docker daemon needs 1 to run directly under 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.

To avoid the need to use the sudo command when running the docker command, create an Unix user group called docker and add users who need to run docker. When you start running the docker daemon, members of the docker user group are given read and write access to Unix socket.

Create the docker user group and add users:

1. Required permissions of root or sudo
2. Create the docker user group and add users


sudo usermod -aG docker your_username

3. Log out and log in to your_username, or log out and log in again once under your_username, which ensures that your user is running the correct permissions.
4. Verify that the sudo command is no longer required to run docker


$ sudo tee /etc/yum.repos.d/docker.repo <<-'EOF'
[dockerrepo]
name=Docker Repository
baseurl=https://yum.dockerproject.org/repo/main/centos/$releasever/
enabled=1
gpgcheck=1
gpgkey=https://yum.dockerproject.org/gpg
EOF
0

Boot up and run docker


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


Related articles: