upgrade docker engine package to docker-ce on CentOS

Older version of Docker were called docker or docker-engine. The Docker Engine package is now called docker-ce .

1. uninstall old versions

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

2. set up the repository

   sudo yum install -y yum-utils
   
   sudo yum-config-manager \
       --add-repo \
       https://download.docker.com/linux/centos/docker-ce.repo

3. install Docker Engine

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

4. start Docker

   sudo systemctl start docker

5. verify that Docker Engine is installed correctly by running the hello-world image.

   sudo docker run hello-world

6. upgrade Docker Engine

   yum -y upgrade docker-ce

7. view docker version number

   docker version --format {{.Server.Os}}-{{.Server.Version}}