Running RHEL-based tools on Debian using containerization

Running RHEL-Based Tools on Debian Using Containerization: A How-To Guide

Linux is popular for its flexibility and the wide variety of specialized tools developed for different distributions. However, sometimes you may find yourself needing to use software or tools specifically designed for one distribution, such as Red Hat Enterprise Linux (RHEL), on another, like Debian. This scenario can pose a challenge due to differing libraries, package managers, and dependencies. One effective solution to bridge this gap is containerization.

Containerization allows you to run a piece of software in a controlled, isolated environment with its dependencies, separate from the host operating system. This ensures that the software operates exactly the same way, regardless of where it's deployed. Tools like Docker make this convenient and efficient. This blog post will guide you through setting up and running RHEL-based tools on a Debian system using Docker.

Step 1: Setting Up Docker on Debian

Before running RHEL-based applications, you first need to install Docker on your Debian system if it's not already installed. You can install Docker using apt, the package manager for Debian:

sudo apt update
sudo apt install docker.io

After installation, it's a good idea to add your user to the Docker group to run Docker commands without sudo:

sudo usermod -aG docker $USER
newgrp docker

Step 2: Preparing the RHEL-based Docker Container

To use RHEL-based tools, start by pulling a RHEL-based Docker image. Here, we'll use CentOS as an example, a free distribution that’s functionally compatible with RHEL:

docker pull centos:7

Now, you can run a container from the CentOS image:

docker run -itd --name rhel-tools centos:7

This command creates and starts a container named rhel-tools using the CentOS 7 image.

Step 3: Installing Tools Using Yum/DNF

Once your container is running, you can install any RHEL-specific tools or software. CentOS 7 uses yum as the default package manager, closely related to RHEL's dnf. Install packages using:

docker exec -it rhel-tools yum install package-name

Replace package-name with the desired software. For example, to install Git:

docker exec -it rhel-tools yum install git

Using DNF (for newer RHEL-based systems)

If you're using a RHEL-based system or a CentOS image that uses dnf, the commands are similar:

docker exec -it rhel-tools dnf install package-name

Step 4: Transferring Files Between the Host and Container

To interact with files between your Debian host and the CentOS container, use Docker's copy command:

# Copy from host to container:
docker cp /path/on/host/file.txt rhel-tools:/path/in/container/file.txt

# Copy from container to host:
docker cp rhel-tools:/path/in/container/file.txt /path/on/host/file.txt

Step 5: Working with Zypper (Optional)

If you choose to run a SUSE-based container which uses zypper rather than yum or dnf, the setup is similar. First, pull an openSUSE image:

docker pull opensuse/leap

Then, create and run a SUSE-based container:

docker run -itd --name suse-tools opensuse/leap

Now, you can install packages using zypper:

docker exec -it suse-tools zypper install package-name

Conclusion

Containerization makes it feasible and straightforward to use software across different Linux distributions. By isolating dependencies and environments, Docker ensures that you can use RHEL-based tools on your Debian machine without any conflicts or extensive modifications. This solution not only increases productivity and flexibility but also leverages the strengths of different distributions according to specific needs. Whether it's for testing, development, or just personal preference, this approach adds another level of versatility to your Linux experience.