5.0 KiB
Install Docker CE on CentOS
WARNING: DO NOT install Docker with yum directly without configuring yum source.
Prerequisites
OS Requirement
Docker CE supports 64-bit version of CentOS 7, and it requires the kernel version to be no older than 3.10. CentOS 7 satisfies the minimum kernel version requirement. But due to the comparatively old kernel, some of the functionalities like overlay2 are unable to be used, and some other features may be unstable.
Uninstall the Old Versions
The old versions of Docker are called docker or docker-engine, you can have them uninstalled with the following command:
$ sudo yum remove docker \
docker-client \
docker-client-latest \
docker-common \
docker-latest \
docker-latest-logrotate \
docker-logrotate \
docker-selinux \
docker-engine-selinux \
docker-engine
Install with yum
Use the following commands to install the dependencies:
$ sudo yum install -y yum-utils \
device-mapper-persistent-data \
lvm2
Due to the network issues in China mainland, it is highly recommended for Chinese users to use Chinese sources. Please refer to the official sources in the comments(they are replaced by a Chinese source).
Use the following command to add dnf source.
$ sudo yum-config-manager \
--add-repo \
https://mirrors.ustc.edu.cn/docker-ce/linux/centos/docker-ce.repo
# Official source
# $ sudo yum-config-manager \
# --add-repo \
# https://download.docker.com/linux/centos/docker-ce.repo
If you want to use the test version of Docker CE, use the following command:
$ sudo yum-config-manager --enable docker-ce-test
As for nightly version:
$ sudo yum-config-manager --enable docker-ce-nightly
Install Docker CE
Update yum source cache，and then install docker-ce.
$ sudo yum makecache fast
$ sudo yum install docker-ce
Install with Automatic Scripts
To simplify the installation process during test or development, Docker official provides a convenient installation script, you can install docker on CentOS with the following script:
$ curl -fsSL get.docker.com -o get-docker.sh
$ sudo sh get-docker.sh --mirror Aliyun
After execution, the script will have everything prepared, and have installed the stable version on your OS.
Start Docker CE
$ sudo systemctl enable docker
$ sudo systemctl start docker
Add Docker Usergroups
Command docker uses Unix socket to communicate with Docker engine by default. Only users of root and docker groups can communicate with Unix socket of the Docker engine.root user is not directly used on Linux systems in general for security. Therefore, it is better to add users who need to use docker to the docker user group.
create docker group:
$ sudo groupadd docker
add current user to docker group:
$ sudo usermod -aG docker $USER
Exit current terminal and relogin to test.
Verify the Installation
$ docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
d1725b59e92d: Pull complete
Digest: sha256:0add3ace90ecb4adbf7777e9aacf18357296e799f81cabc9fde470971e499788
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.
(amd64)
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 ID:
https://hub.docker.com/
For more examples and ideas, visit:
https://docs.docker.com/get-started/
If it shows the above message, it means your installation is successful.
Registry Mirror(In China)
If you pull docker images very slowly, then you can configure Registry Mirror.
Add kernel Parameters
If you see the following warnings when using Docker CE,
WARNING: bridge-nf-call-iptables is disabled
WARNING: bridge-nf-call-ip6tables is disabled
Please add the kernel parameters to enable these features.
$ sudo tee -a /etc/sysctl.conf <<-EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
Then reload the sysctl.confg
$ sudo sysctl -p