From 8cf3cd91b2b6052f99fbe78f80141e57fcc02230 Mon Sep 17 00:00:00 2001 From: Silvan Mosberger Date: Tue, 16 Jan 2024 23:33:53 +0100 Subject: [PATCH] check-by-name: Update contributor docs Now that the tooling is pinned instead of being fetched indirectly from the channel, the docs need some updating --- .github/workflows/check-by-name.yml | 5 +++-- nixos/release-combined.nix | 4 ++-- pkgs/test/nixpkgs-check-by-name/README.md | 21 +++++-------------- .../nixpkgs-check-by-name/scripts/README.md | 18 ++++++++++++++-- 4 files changed, 26 insertions(+), 22 deletions(-) diff --git a/.github/workflows/check-by-name.yml b/.github/workflows/check-by-name.yml index 983b10e4cd40..0093560cf3c2 100644 --- a/.github/workflows/check-by-name.yml +++ b/.github/workflows/check-by-name.yml @@ -4,8 +4,8 @@ # When you make changes to this workflow, also update pkgs/test/nixpkgs-check-by-name/scripts/run-local.sh adequately name: Check pkgs/by-name -# The pre-built tool is fetched from a channel, -# making it work predictable on all PRs. +# The tool is pinned to a pre-built version on Hydra, +# see pkgs/test/nixpkgs-check-by-name/scripts/README.md on: # Using pull_request_target instead of pull_request avoids having to approve first time contributors pull_request_target @@ -92,6 +92,7 @@ jobs: echo "base=$base" >> "$GITHUB_ENV" - uses: cachix/install-nix-action@7ac1ec25491415c381d9b62f0657c7a028df52a7 # v24 - name: Fetching the pinned tool + # Update the pinned version using pkgs/test/nixpkgs-check-by-name/scripts/update-pinned-tool.sh run: | # Get the direct /nix/store path from the pin to avoid having to evaluate Nixpkgs toolPath=$(jq -r '."ci-path"' pkgs/test/nixpkgs-check-by-name/scripts/pinned-tool.json) diff --git a/nixos/release-combined.nix b/nixos/release-combined.nix index a2e141b5bcaf..7700441b1d6b 100644 --- a/nixos/release-combined.nix +++ b/nixos/release-combined.nix @@ -171,8 +171,8 @@ in rec { (onSystems ["x86_64-linux"] "nixpkgs.mesa_i686") # i686 sanity check + useful ["nixpkgs.tarball"] - # Ensure that nixpkgs-check-by-name is available in all release channels and nixos-unstable, - # so that a pre-built version can be used in CI for PR's on the corresponding development branches. + # Ensure that nixpkgs-check-by-name is available in nixos-unstable, + # so that a pre-built version can be used in CI for PR's # See ../pkgs/test/nixpkgs-check-by-name/README.md (onSystems ["x86_64-linux"] "nixpkgs.tests.nixpkgs-check-by-name") ]; diff --git a/pkgs/test/nixpkgs-check-by-name/README.md b/pkgs/test/nixpkgs-check-by-name/README.md index d779529c7baf..7dcd807b2710 100644 --- a/pkgs/test/nixpkgs-check-by-name/README.md +++ b/pkgs/test/nixpkgs-check-by-name/README.md @@ -1,9 +1,13 @@ # Nixpkgs pkgs/by-name checker This directory implements a program to check the [validity](#validity-checks) of the `pkgs/by-name` Nixpkgs directory. -It is being used by [this GitHub Actions workflow](../../../.github/workflows/check-by-name.yml). This is part of the implementation of [RFC 140](https://github.com/NixOS/rfcs/pull/140). +A [pinned version](./scripts/pinned-tool.json) of this tool is used by [this GitHub Actions workflow](../../../.github/workflows/check-by-name.yml). +See [./scripts](./scripts/README.md#update-pinned-toolsh) for how to update the pinned version. + +The source of the tool being right inside Nixpkgs allows any Nixpkgs committer to make updates to it. + ## Interface The interface of the tool is shown with `--help`: @@ -96,18 +100,3 @@ Tests are declared in [`./tests`](./tests) as subdirectories imitating Nixpkgs w - `expected` (optional): A file containing the expected standard output. The default is expecting an empty standard output. - -## Hydra builds - -This program will always be available pre-built for `x86_64-linux` on the `nixos-unstable` channel and `nixos-XX.YY` channels. -This is ensured by including it in the `tested` jobset description in [`nixos/release-combined.nix`](../../../nixos/release-combined.nix). - -This allows CI for PRs to development branches `master` and `release-XX.YY` to fetch the pre-built program from the corresponding channel and use that to check the PR. This has the following benefits: -- It allows CI to check all PRs, even if they would break the CI tooling. -- It makes the CI check very fast, since no Nix builds need to be done, even for mass rebuilds. -- It improves security, since we don't have to build potentially untrusted code from PRs. - The tool only needs a very minimal Nix evaluation at runtime, which can work with [readonly-mode](https://nixos.org/manual/nix/stable/command-ref/opt-common.html#opt-readonly-mode) and [restrict-eval](https://nixos.org/manual/nix/stable/command-ref/conf-file.html#conf-restrict-eval). -- It allows anybody to make updates to the tooling and for those updates to be automatically used by CI without needing a separate release mechanism. - -The tradeoff is that there's a delay between updates to the tool and those updates being used by CI. -This needs to be considered when updating the [API](#api). diff --git a/pkgs/test/nixpkgs-check-by-name/scripts/README.md b/pkgs/test/nixpkgs-check-by-name/scripts/README.md index cfef2115d4c7..ccd4108ea288 100644 --- a/pkgs/test/nixpkgs-check-by-name/scripts/README.md +++ b/pkgs/test/nixpkgs-check-by-name/scripts/README.md @@ -19,6 +19,20 @@ Arguments: ## `./update-pinned-tool.sh` Updates the pinned CI tool in [`./pinned-tool.json`](./pinned-tool.json) to the -[latest version from the `nixos-unstable` channel](https://hydra.nixos.org/job/nixos/trunk-combined/nixpkgs.tests.nixpkgs-check-by-name.x86_64-linux) +[latest version from the `nixos-unstable` channel](https://hydra.nixos.org/job/nixos/trunk-combined/nixpkgs.tests.nixpkgs-check-by-name.x86_64-linux). + +This script needs to be called manually when the CI tooling needs to be updated. + +The `pinned-tool.json` file gets populated with both: +- The `/nix/store` path for `x86_64-linux`, such that CI doesn't have to evaluate Nixpkgs and can directly fetch it from the cache instead. +- The Nixpkgs revision, such that the `./run-local.sh` script can be used to run the checks locally on any system. + +To ensure that the tool is always pre-built for `x86_64-linux` in the `nixos-unstable` channel, +it's included in the `tested` jobset description in [`nixos/release-combined.nix`](../../../nixos/release-combined.nix). + +Why not just build the tooling right from the PRs Nixpkgs version? +- Because it allows CI to check all PRs, even if they would break the CI tooling. +- Because it makes the CI check very fast, since no Nix builds need to be done, even for mass rebuilds. +- Because it improves security, since we don't have to build potentially untrusted code from PRs. + The tool only needs a very minimal Nix evaluation at runtime, which can work with [readonly-mode](https://nixos.org/manual/nix/stable/command-ref/opt-common.html#opt-readonly-mode) and [restrict-eval](https://nixos.org/manual/nix/stable/command-ref/conf-file.html#conf-restrict-eval). -This script is called manually once the CI tooling needs to be updated.