How to lock Docker version in Centos/RHEL

Expected Outcome

This guide describes how to lock the installed Docker version on a CentOS or RHEL host to prevent it from being upgraded during system-wide package updates. This ensures that the Docker version remains compatible with Terraform Enterprise requirements.

Prerequisites

• A running instance of Terraform Enterprise.
• A CentOS or RHEL 7/8 host.
• Root or sudo access to the host.
• Docker CE installed.

Use Case

Locking the Docker version is necessary to maintain a stable and supported environment for Terraform Enterprise. Following these steps ensures the installed version of Docker meets the Terraform Enterprise requirements.

Procedure

1. Install the versionlock plugin.

   For RHEL 7, execute the following command.

   $ yum install yum-plugin-versionlock

   For RHEL 8, execute the following command.

   $ yum install python3-dnf-plugin-versionlock

2. Identify installed Docker packages.

   List the currently installed Docker-related packages to identify their exact version strings.

   $ yum list docker-ce docker-ce-cli docker-ce-rootless-extras containerd.io --showduplicates | sort -r

   The output displays the installed versions. Note the full package name and version for each component.

   ## Example output

docker-ce.x86_64 3:20.10.17-3.el7 @docker-ce-stable docker-ce-rootless-extras.x88_64 23.0.1-1.el7 @docker-ce-stable docker-ce-cli.x86_64 1:20.10.17-3.el7 @docker-ce-stable containerd.io.x86_64 1.6.18-3.1.el7 @docker-ce-stable ```

3. Lock the package versions.

   Use the versionlock command with the package versions identified in the previous step.

   $ yum versionlock docker-ce-20.10.17-3.el7 docker-ce-cli-20.10.17-3.el7 docker-ce-rootless-extras-23.0.1-1.el7 containerd.io-1.6.18-3.1.el7

   The command returns a confirmation that the version lock was added for each package.

   Loaded plugins: fastestmirror, versionlock
   Adding versionlock on: 0:docker-ce-rootless-extras-23.0.1-1.el7
   Adding versionlock on: 1:docker-ce-cli-20.10.17-3.el7
   Adding versionlock on: 3:docker-ce-20.10.17-3.el7
   Adding versionlock on: 0:containerd.io-1.6.18-3.1.el7
   versionlock added: 4

4. Remove the version lock (Optional).

   To upgrade Docker in the future, you must first remove the lock. Execute the versionlock clear command.

   $ yum versionlock clear

Additional Information

• Terraform runs don't execute in Terraform Enterprise