Replacing dependency on Ubuntu-specific /etc/lsb-release dependency to allow landscape-package-reporter to work with Debian

According to the FAQ 'We don't test landscape-client on Debian, but we don't really try to make it difficult for Debian users.' (https://help.landscape.canonical.com/FAQ#Does_landscape-client_work_with_Debian.3F)

I have paid for and been trialling landscape-client on Debian 9 and 10 (Jessie/Buster) and does indeed work remarkably well - computers can be added, monitoring works and in general all seems happy. The only exception is with 'landscape-package-reporter' which returns an error because '/etc/lsb-release' does not exist (see error log below).

This appears to be a conscious decision by the Debian project as they didn't believe it was necessary for LSB compatibility https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=444678 - although the command /usr/bin/lsb_release provides the same information and *is* shared with Ubuntu.

If I manually create the relevant file on Debian with /usr/bin/lsb-release, everything else works perfectly:

apt install lsb-release
echo DISTRIB_ID=$(lsb_release -si) > /etc/lsb-release
echo DISTRIB_RELEASE=$(lsb_release -sr) >> /etc/lsb-release
echo DISTRIB_CODENAME=$(lsb_release -sc) >> /etc/lsb-release
echo DISTRIB_DESCRIPTION=\"$(lsb_release -sd)\" >> /etc/lsb-release

This allows landscape-package-reporter to run and removes the 'No package information is available for the selected computers' warning in the Landscape console which otherwise appears.

I was wondering if you could update landscape-package-reporter to use lsb_release instead of /etc/lsb-release. I am aware that Debian is unsupported. But a small, hopefully insignificant change like this would mean it could work on both, which many people including myself looking for a nice updating GUI for their Debian installs would find very helpful!

Hoping you agree :)

--

2022-09-20 13:33:52,570 WARNING [MainThread] Couldn't determine which hash=>id database to use: [Errno 2] No such file or directory: '/etc/lsb-release'
2022-09-20 13:33:52,576 WARNING [MainThread] Couldn't determine which hash=>id database to use: [Errno 2] No such file or directory: '/etc/lsb-release'
2022-09-20 13:33:52,634 INFO [MainThread] Received 500 package hash => id translations, 0 hashes are unknown.
2022-09-20 13:35:32,215 INFO [MainThread] Queuing request for package hash => id translation on 500 hash(es).
2022-09-20 13:35:32,262 ERROR [MainThread] None
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/twisted/internet/defer.py", line 654, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "/usr/lib/python3/dist-packages/landscape/client/package/reporter.py", line 95, in <lambda>
    result.addCallback(lambda x: self.detect_changes())
  File "/usr/lib/python3/dist-packages/landscape/client/package/reporter.py", line 556, in detect_changes
    deferred = self.detect_packages_changes()
  File "/usr/lib/python3/dist-packages/landscape/client/package/reporter.py", line 565, in detect_packages_changes
    return self._compute_packages_changes()
  File "/usr/lib/python3/dist-packages/landscape/client/package/reporter.py", line 631, in _compute_packages_changes
    lsb = parse_lsb_release(LSB_RELEASE_FILENAME)
  File "/usr/lib/python3/dist-packages/landscape/lib/lsb_release.py", line 15, in parse_lsb_release
    fd = open(lsb_release_filename, "r")
FileNotFoundError: [Errno 2] No such file or directory: '/etc/lsb-release'