Checkbox stack migration from Launchpad to GitHub

[Sylvain Pineau]

Hi all,

TL;DR

The checkbox stack is migrating from Launchpad repositories to a 
"monorepo" on GitHub.
The certification tools team aims at officially switching on Friday 7th 
October (11:00 UTC).

Rationale:

The Checkbox stack is made of several components from the core python 
runtime
to test providers, all hosted separately in different repositories.

- Preparing a development environment requires cloning multiple sources 
which
   is not obvious for new contributors and promotes duplicating code 
(multiple
   solutions to the same problems because the whole inventory is not 
necessarily
   clear).

- New features or bug fixes involving code across multiple components 
are not
   easy to contribute or review together (e.g. code + packaging).

- Lax review process because we cannot gate changes with automations: 
pre-merge
   CI automations are presently not available, and if these were to be 
maintained
   across a dozen repositories, would be unattractive to build even if 
possible.

- Maintaining Checkbox and Checkbox core snaps packaging in branches for 
each
   supported bases is unnecessary complex.

FAQ:

Q: Where's the monorepo?
A: https://github.com/canonical/checkbox 
<https://github.com/canonical/checkbox>

Q: Can I use it now?
A: No, it's not fully configured.

Q: When can I start submitting PR?
A: on Friday 7th October (11:00 UTC)

Q: What does it mean for my Launchpad existing merge proposals [1]?
A: Please ask for reviews this week in order to land your merge proposals
before the final import planned on Friday, that’s the best solution.
If MRs can’t be merged before the migration they won’t be left behind as 
they
can be re-posted as Pull requests on GitHub.

Q: What if I have a fix to submit for checkbox?
A: Please wait and submit it next week as a Pull request.

Q: Is the full git history preserved?
A: Yes it is, thanks to git-filter-repo.

Q: Will Launchpad repositories be turned into Read-only?
A: Probably yes (by setting up more restrictive permissions, see [2]).

[1] https://code.launchpad.net/checkbox-project/+activereviews 
<https://code.launchpad.net/checkbox-project/+activereviews>
[2] https://help.launchpad.net/Code/Git#Permissions 
<https://help.launchpad.net/Code/Git#Permissions>

Sylvain