Come hang out in the Matrix channel. :)

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 all tests:

$ 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.

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

$ nix run nixpkgs#colmena -- apply

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

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.

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

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

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

$ 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

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

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

While creating NixOS tests:

While creating an XML config generator for Radarr: