Install Docker CE in CentOS/RHEL 7

Installing Docker CE in CentOS/RHEL 7 is a trivial process but it is not true in all cases. Specially, when we deal with open source products, maintaining and patching might be an issue for doing it in timely manner. Community forums and other sources are our life savers to find workarounds for any encountering roadblocks.

1. Remove old version

yum remove docker \
           docker-client \
           docker-client-latest \
           docker-common \
           docker-latest \
           docker-latest-logrotate \
           docker-logrotate \
           docker-engine

2. Set up Docker repository

Install package manager.
```
yum install -y yum-utils
```
Add the Docker repository to the repository database.
```
yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
```
If an error has been received, it has to be applied a workaround. As per version 7.9 on Oct 6, 2020, the repository path is broken and the path needs to be adjusted manually with the command.
```
yum-config-manager --setopt="docker-ce-stable.baseurl=https://download.docker.com/linux/centos/7/x86_64/stable" --save
```

3. Install the latest version of Docker CE

yum install docker-ce docker-ce-cli containerd.io

4. Enable and run docker daemon

systemctl enable docker
systemctl start docker

5. Validate installation

Docker service status

systemctl status docker

Output

● docker.service - Docker Application Container Engine
   Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled; vendor preset: disabled)
   Active: active (running) since Tue 2020-10-06 10:08:03 EDT; 1 weeks 5 days ago

Run the sample image

docker run -it centos echo Hello-World