Adapt linux repository generation to allow for the Mullvad browser

[faern]

We want to add the Mullvad Browser into our Linux repositories. Currently the Linux repository generation is very tied to the app (since it's the only package in them). We need to change this so we can add more products into the repository, but also so we can eventually transfer the ownership of the repository generation to another team, once it's no longer app specific.

This PR moves in that direction. The general intended design is the following:

There is a new build-linux-repositories.sh script. We will run three instances of this (the services themselves are oneshot but will be triggered periodically by a systemd timer):

• build-linux-repositories@production.service
• build-linux-repositories@staging.service
• build-linux-repositories@dev.service

Each run has a server environment (production, staging or dev). Each instance consume its own "inbox". This is where products dump notification files telling the repository building service it has new artifacts to pick up for a repository. See documentation at the top of build-linux-repositories.sh for more details.

Then each product we want to publish to the repositories are responsible for dumping their artifacts somewhere and write a "notification file" to the inbox of the above mentioned service.

The repository building service can trigger periodically (it does nothing if no .src files are present in its inbox)

What does each file do?

• buildserver-build.sh - It's the script the app team run constantly to build the app when branches move and tags are pushed. It has very small changes
• buildserver-config.sh configuration used by the app scripts. These are app specific and do not relate to the linux repository building service or the browser.
• publish-app-to-repositories.sh - The script used by the app team to push app artifacts to the Linux repository building service.
• build-linux-repositories-config.sh - Config specific to the repository building service. Some new variables, and some moved from buildserver-config.sh
• prepare-{apt,rpm}-repository.sh - These take a directory of artifacts and produce repositories with metadata and signatures. These were around before, but now they have been adopted to handle more products and being run from build-linux-repositories.sh instead of buildserver-build.sh
• build-linux-repositories.sh - The main script of the repository building service. Handle the parsing of the inbox, moving around of artifacts and triggering build and upload of repositories.
• download-mullvad-browser.sh - Script provided by infra to download the browser, verify it, and send it to the repository building service.

---

This change is 

[linear]

DES-866 Adapt Linux repository generation to encompass Mullvad Browser

[raksooo]

Reviewed 8 of 14 files at r1.
Reviewable status: 8 of 14 files reviewed, all discussions resolved

[oskaralmlov]

LGTM 👍

[oskaralmlov]

Looks Great To Me

[raksooo]

Reviewed 1 of 14 files at r1, 1 of 5 files at r2, 2 of 7 files at r5, 2 of 2 files at r6, 3 of 3 files at r7, 4 of 6 files at r9, 1 of 3 files at r10, 2 of 2 files at r11.
Reviewable status: 13 of 14 files reviewed, 3 unresolved discussions (waiting on @faern and @oskaralmlov)

---

ci/linux-repository-builder/prepare-rpm-repository.sh line 49 at r11 (raw file):

fi

# Writes the mullvad.repo config file to the repository

This line is only 55 characters, you could fit this comment on fewer lines if you make them longer.

[raksooo]

Reviewed 1 of 14 files at r1.
Reviewable status: all files reviewed, 3 unresolved discussions (waiting on @faern and @oskaralmlov)

[raksooo]

Reviewed 5 of 5 files at r12.
Reviewable status: all files reviewed, 3 unresolved discussions (waiting on @faern and @oskaralmlov)

[raksooo]

Reviewed 3 of 3 files at r13.
Reviewable status: all files reviewed, 3 unresolved discussions (waiting on @faern and @oskaralmlov)

[faern]

Reviewable status: all files reviewed, 3 unresolved discussions (waiting on @oskaralmlov)

---

ci/build-linux-repositories@.service line 21 at r2 (raw file):

Previously, oskaralmlov (Oskar Almlöv) wrote…

You don't need to enable the service as the timer will take care of running it.

Done.