Adds initial builder-focal molecule scenario

[kushaldas]

Status

Ready for review

Description of Changes

Fixes #5446

This will enable creating the builder image sd-builder-focal
from the Dockerfile in this commit. We can then update the next
image_hash in the next commit.

Testing

• make build-debs-focal command should start building packages using the Focal container image. But, the actual debian package builds will fail. The fixes for the actual packages will come in future PRs.

Deployment

Any special considerations for deployment? Consider both:

1. Upgrading existing production instances.
2. New installs.

Checklist

If you made changes to the server application code:

• Linting (make lint) and tests (make test) pass in the development container

If you made changes to securedrop-admin:

• Linting and tests (make -C admin test) pass in the admin development container

If you made changes to the system configuration:

• Configuration tests pass

If you made non-trivial code changes:

• I have written a test plan and validated it for this PR

If you made changes to documentation:

• Doc linting (make docs-lint) passed locally

If you added or updated a code dependency:

Choose one of the following:

• I have performed a diff review and pasted the contents to the packaging wiki
• I would like someone else to do the diff review

[conorsch]

@kushaldas All set! I've pushed the new focal image based on the logic you've added here. I also took the liberty of appending a few commits. On my machine, I was able to pull the image, confirm it was really Focal, and even build most of the packages—the failing ones are already tracked for follow-up in #5449.

Before you mark as ready-for-review, please review the additional commits to make sure you agree with them, then add some steps to the test plan for the next reviewer!

[conorsch]

Ran the new makefile target, and i'm getting new Focal packages!

 $ tree build/
build/
├── focal
│   ├── securedrop-config-0.1.3+1.6.0~rc1-amd64.deb
│   ├── securedrop-grsec-4.14.188-amd64.deb
│   ├── securedrop-keyring-0.1.4+1.6.0~rc1-amd64.deb
│   ├── securedrop-ossec-agent-3.6.0+1.6.0~rc1-amd64.deb
│   └── securedrop-ossec-server-3.6.0+1.6.0~rc1-amd64.deb
└── xenial
    ├── ossec-agent-3.6.0-amd64.deb
    ├── ossec-server-3.6.0-amd64.deb
    ├── securedrop-app-code_1.6.0~rc1+xenial_amd64.deb
    ├── securedrop-app-code_1.6.0~rc1+xenial.tar.gz
    ├── securedrop-config-0.1.3+1.6.0~rc1-amd64.deb
    ├── securedrop-grsec-4.14.188-amd64.deb
    ├── securedrop-keyring-0.1.4+1.6.0~rc1-amd64.deb
    ├── securedrop-ossec-agent-3.6.0+1.6.0~rc1-amd64.deb
    └── securedrop-ossec-server-3.6.0+1.6.0~rc1-amd64.deb

As expected, there are still a few failing packages for focal (viz. securedrop-app-code, ossec-agent, ossec-server), but those follow-ups are well tracked in the epic, so approving for merge.