2.4.3.2 Install or Reinstall the Docker

To install or reinstall the Docker if you have already uninstalled it as shown in the previous section, perform the following steps:

1. Execute the following command in the command prompt to update the system:$ sudo yum update -y
2. Execute the following command in the command prompt to update the yum repository:
   If the public-yum-ol7.repo file is available in the /etc/yum.repos.d directory, then open it in the Vi editor with the command sudo vi /etc/yum.repos.d/ public-yum-ol7.repo and enable the ol7_addons repository to install the latest Docker release (19.03.11.ol).
3. Execute the following command in the command prompt to install Docker:$ sudo yum install docker-engine -y
4. Execute the following command in the command prompt and start the Docker service:$ sudo service docker start
5. Execute the following command in the command prompt and verify whether the Docker service is running:$ sudo docker run hello-worldAfter you verify that the service is running, the Docker installation is successful.
6. Docker installation uses the following pre-configured ports which must be enabled in the server before installing the applications.
   • 9999
   • 6666
   • 6507
   • 6509
   • 6500
   • 6505
   • 6501
   • 10101
   • 7001
   • 7002
   • 7004
   • 7005
   • 7006
   • 7011
   • 5556
   • 8453