Running Debian Software on Red Hat Enterprise Linux (RHEL) Using Alien

For system administrators or software developers who work in environments using different Linux distributions, compatibility issues often arise. Software packages designed for one distribution are not always readily usable on another due to differing package management systems and library dependencies. This is especially true for those who primarily use Red Hat Enterprise Linux (RHEL) but need software packaged for Debian-based distributions. Fortunately, a tool named alien can help to bridge this gap. In this blog, we'll explore how to use alien to convert Debian packages for use on RHEL, and provide instructions for handling these packages across different Linux distributions.

What is Alien?

Alien is a program that converts between different Linux package formats, including Debian (.deb) packages to Red Hat (.rpm) packages. While it's not guaranteed to work for all packages due to potential conflicts in dependencies and scripts, it can be a valuable tool when there are no equivalent packages available on your primary distribution.

Installing Alien on RHEL

Before you can use alien, you'll need to install it. As alien is not available in the default RHEL repositories, you'll first need to enable the EPEL (Extra Packages for Enterprise Linux) repository which provides additional packages for RHEL. Run the following commands to install alien:

sudo dnf install epel-release
sudo dnf install alien

Once installed, you can now use alien to convert .deb packages to .rpm.

Converting a Debian Package to RHEL

To convert a Debian package, first download the .deb package file to your RHEL system. Once you have your Debian package, use the following command to convert it to an RPM package:

sudo alien -r your-package.deb

This will create an .rpm file from the .deb package. Now, you can install this package using dnf:

sudo dnf install your-package.rpm

Potential Issues and Considerations

Dependencies: If the software depends on other packages that are only available for Debian, you might need to also convert those packages or find equivalent RPM packages.
Scripts: Some pre-install or post-install scripts in the Debian packages may not execute perfectly on RHEL. These scripts may require modification to work correctly.

Using Converted Packages Across Other Distributions

While our focus has been on converting Debian packages for RHEL with alien, the reverse is also possible. Moreover, for those working with SUSE-based systems (which use zypper as a package manager), the process is similar:

On openSUSE or SUSE Linux Enterprise:

Install alien using zypper:
```
sudo zypper install alien
```
Convert RPM package to DEB (if needed) or vice versa:
```
sudo alien -d your-package.rpm
```
Install the converted package:
```
sudo zypper install your-package.deb
```

Or, simply install an RPM directly if it's already converted for use on RHEL.

Conclusion

Using alien to convert software packages between different Linux distributions can be a lifeline when specific software is not available in your distribution's format. Although alien can solve many compatibility issues, it is always advisable to look for native packages or official distribution-specific repositories first due to the potential issues with dependencies and scripts. Always test software extensively in safe, non-production environments after using alien to ensure functionality and security.