Contributing

Table of Contents

Chat Support
Upstream Changes
Run tests
Upload test results to CI
Deploy using colmena
Use a local version of selfhostblocks
Diff changes
Generate random secret
Links that helped

All issues and Pull Requests are welcome!

For Pull Requests, if they are substantial changes, please open an issue to discuss the details first.

Chat Support

Come hang out in the Matrix channel. :)

Upstream Changes

One important goal of SHB is to be the smallest amount of code above what is available in nixpkgs. It should be the minimum necessary to make packages available there conform with the contracts. This way, there are less chance of breakage when nixpkgs gets updated. I intend to upstream to nixpkgs as much of those as makes sense.

Run tests

Run all tests:

$ nix build .#checks.${system}.all
# or
$ nix flake check
# or
$ nix run github:Mic92/nix-fast-build -- --skip-cached --flake ".#checks.$(nix eval --raw --impure --expr builtins.currentSystem)"

Run one group of tests:

$ nix build .#checks.${system}.modules
$ nix build .#checks.${system}.vm_postgresql_peerAuth

Run one VM test interactively:

$ nix run .#checks.${system}.vm_postgresql_peerAuth.driverInteractive

When you get to the shell, run either start_all() or test_script(). The former just starts all the VMs and service, then you can introspect. The latter also starts the VMs if they are not yet and then will run the test script.

Upload test results to CI

Github actions do now have hardware acceleration, so running them there is not slow anymore. If needed, the tests results can still be pushed to cachix so they can be reused in CI.

After running the nix-fast-build command from the previous section, run:

$ find . -type l -name "result-vm_*" | xargs readlink | nix run nixpkgs#cachix -- push selfhostblocks

Deploy using colmena

$ nix run nixpkgs#colmena -- apply

Use a local version of selfhostblocks

This works with any flake input you have. Either, change the .url field directly in you flake.nix:

selfhostblocks.url = "/home/me/projects/selfhostblocks";

Or override on the command line:

$ nix flake lock --override-input selfhostblocks ../selfhostblocks

I usually combine the override snippet above with deploying:

$ nix flake lock --override-input selfhostblocks ../selfhostblocks && nix run nixpkgs#colmena -- apply

Diff changes

First, you must know what to compare. You need to know the path to the nix store of what is already deployed and to what you will deploy.

What is deployed

To know what is deployed, either just stash the changes you made and run build:

$ nix run nixpkgs#colmena -- build
...
Built "/nix/store/yyw9rgn8v5jrn4657vwpg01ydq0hazgx-nixos-system-baryum-23.11pre-git"

Or ask the target machine:

$ nix run nixpkgs#colmena -- exec -v readlink -f /run/current-system
baryum | /nix/store/77n1hwhgmr9z0x3gs8z2g6cfx8gkr4nm-nixos-system-baryum-23.11pre-git

What will get deployed

Assuming you made some changes, then instead of deploying with apply, just build:

$ nix run nixpkgs#colmena -- build
...
Built "/nix/store/16n1klx5cxkjpqhrdf0k12npx3vn5042-nixos-system-baryum-23.11pre-git"

Get the full diff

With nix-diff:

$ nix run nixpkgs#nix-diff -- \
  /nix/store/yyw9rgn8v5jrn4657vwpg01ydq0hazgx-nixos-system-baryum-23.11pre-git \
  /nix/store/16n1klx5cxkjpqhrdf0k12npx3vn5042-nixos-system-baryum-23.11pre-git \
  --color always | less

Get version bumps

A nice summary of version changes can be produced with:

$ nix run nixpkgs#nvd -- diff \
  /nix/store/yyw9rgn8v5jrn4657vwpg01ydq0hazgx-nixos-system-baryum-23.11pre-git \
  /nix/store/16n1klx5cxkjpqhrdf0k12npx3vn5042-nixos-system-baryum-23.11pre-git \

Generate random secret

$ nix run nixpkgs#openssl -- rand -hex 64

Links that helped

While creating NixOS tests:

  • https://www.haskellforall.com/2020/11/how-to-use-nixos-for-lightweight.html

  • https://nixos.org/manual/nixos/stable/index.html#sec-nixos-tests

While creating an XML config generator for Radarr:

  • https://stackoverflow.com/questions/4906977/how-can-i-access-environment-variables-in-python

  • https://stackoverflow.com/questions/7771011/how-can-i-parse-read-and-use-json-in-python

  • https://github.com/NixOS/nixpkgs/blob/master/pkgs/build-support/writers/scripts.nix

  • https://stackoverflow.com/questions/43837691/how-to-package-a-single-python-script-with-nix

  • https://ryantm.github.io/nixpkgs/languages-frameworks/python/#python

  • https://ryantm.github.io/nixpkgs/hooks/python/#setup-hook-python

  • https://ryantm.github.io/nixpkgs/builders/trivial-builders/

  • https://discourse.nixos.org/t/basic-flake-run-existing-python-bash-script/19886

  • https://docs.python.org/3/tutorial/inputoutput.html

  • https://pypi.org/project/json2xml/

  • https://www.geeksforgeeks.org/serialize-python-dictionary-to-xml/

  • https://nixos.org/manual/nix/stable/language/builtins.html#builtins-toXML

  • https://github.com/NixOS/nixpkgs/blob/master/pkgs/pkgs-lib/formats.nix