Support for AlmaLinux and Rocky Linux in get.docker.com install script

Support for AlmaLinux and Rocky Linux in get.docker.com install script

Description

The current installation script available at https://get.docker.com works well for major distributions like Ubuntu, Debian, and CentOS/RHEL.
However, it fails to recognize or properly support AlmaLinux and Rocky Linux, which are both RHEL-compatible distributions widely adopted as CentOS/RHEL successors.

Expected Behavior

The script should detect and install Docker correctly on AlmaLinux and Rocky Linux, just as it does for CentOS/RHEL.

Actual Behavior

When running the script on AlmaLinux or Rocky Linux, it does not recognize the OS or exits with a message indicating that the distribution is unsupported.

Steps to Reproduce

1. Run the following command on a fresh AlmaLinux or Rocky Linux installation:

   curl -fsSL https://get.docker.com | sh
   

2. Observe that the installer fails due to unrecognized OS ID.

Suggested Improvement

Add official detection and support in the script for:

• AlmaLinux
• Rocky Linux

Both distributions are binary-compatible with RHEL and share similar package management tools (dnf/yum), so adapting the existing CentOS/RHEL logic should be straightforward.

Environment

• OS: AlmaLinux / Rocky Linux (8.x / 9.x / 10.x)
• Script: Latest from https://get.docker.com

Additional Context

AlmaLinux and Rocky Linux are now widely used in enterprise and community environments as CentOS replacements.
Adding support would improve usability and align with Docker’s support for RHEL-based systems.

Start with the get.docker.com installation script and inspect how it detects and handles CentOS/RHEL. Adapt that existing path for AlmaLinux and Rocky Linux, then verify that the script recognizes both distributions and completes installation using their dnf/yum-compatible tooling. Done means neither distribution is rejected as unsupported.