tvl-depot/default.nix
Vincent Ambo 0779f96687 feat(nix/buildkite): Check target map of parent to determine skips
This changes the logic for build pipeline generation to inspect
an (optional) parentTargetMap attribute which contains the derivation
map of a target commit.

Targets that existed in a parent commit with the same drv hash will be
skipped, as they are not considered to have changed.

This does not yet wire up any logic for retrieving the target map from
storage, meaning that at this commit all targets are always built.

The intention is that we will have logic to fetch the target
map (initially from Buildkite artefact storage), which we then pass to
the depot via externalArgs when actually generating the pipeline.

Change-Id: I3373c60aaf4b56b94c6ab64e2e5eef68dea9287c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/4946
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-01-17 11:49:01 +00:00

117 lines
3.6 KiB
Nix

# This file sets up the top-level package set by traversing the package tree
# (see //nix/readTree for details) and constructing a matching attribute set
# tree.
{ nixpkgsBisectPath ? null
, parentTargetMap ? null
, nixpkgsConfig ? {}, ... }@args:
let
inherit (builtins)
filter
;
readTree = import ./nix/readTree {};
# Disallow access to //users from other depot parts.
usersFilter = readTree.restrictFolder {
folder = "users";
reason = ''
Code under //users is not considered stable or dependable in the
wider depot context. If a project under //users is required by
something else, please move it to a different depot path.
'';
exceptions = [
# whitby is allowed to access //users for several reasons:
#
# 1. User SSH keys are set in //users.
# 2. Some personal websites or demo projects are served from it.
[ "ops" "machines" "whitby" ]
# Due to evaluation order this also affects these targets.
# TODO(tazjin): Can this one be removed somehow?
[ "ops" "nixos" ]
[ "ops" "machines" "all-systems" ]
];
};
# Disallow access to //corp from other depot parts.
corpFilter = readTree.restrictFolder {
folder = "corp";
reason = ''
Code under //corp may use incompatible licensing terms with
other depot parts and should not be used anywhere else.
'';
exceptions = [
# For the same reason as above, whitby is exempt to serve the
# corp website.
[ "ops" "machines" "whitby" ]
[ "ops" "nixos" ]
[ "ops" "machines" "all-systems" ]
];
};
readDepot = depotArgs: readTree {
args = depotArgs;
path = ./.;
filter = parts: args: corpFilter parts (usersFilter parts args);
scopedArgs = {
__findFile = _: _: throw "Do not import from NIX_PATH in the depot!";
};
};
# To determine build targets, we walk through the depot tree and
# fetch attributes that were imported by readTree and are buildable.
#
# Any build target that contains `meta.ci = false` will be skipped.
# Is this tree node eligible for build inclusion?
eligible = node: (node ? outPath) && (node.meta.ci or true);
in readTree.fix(self: (readDepot {
depot = self;
# Pass third_party as 'pkgs' (for compatibility with external
# imports for certain subdirectories)
pkgs = self.third_party.nixpkgs;
# Expose lib attribute to packages.
lib = self.third_party.nixpkgs.lib;
# Pass arguments passed to the entire depot through, for packages
# that would like to add functionality based on this.
#
# Note that it is intended for exceptional circumstance, such as
# debugging by bisecting nixpkgs.
externalArgs = args;
}) // {
# Make the path to the depot available for things that might need it
# (e.g. NixOS module inclusions)
path = self.third_party.nixpkgs.lib.cleanSourceWith {
name = "depot";
src = ./.;
filter = self.third_party.nixpkgs.lib.cleanSourceFilter;
};
# List of all buildable targets, for CI purposes.
#
# Note: To prevent infinite recursion, this *must* be a nested
# attribute set (which does not have a __readTree attribute).
ci.targets = readTree.gather eligible (self // {
# remove the pipelines themselves from the set over which to
# generate pipelines because that also leads to infinite
# recursion.
ops = self.ops // { pipelines = null; };
# remove nixpkgs from the set, for obvious reasons.
third_party = self.third_party // { nixpkgs = null; };
});
# Derivation that gcroots all depot targets.
ci.gcroot = with self.third_party.nixpkgs; makeSetupHook {
name = "depot-gcroot";
deps = self.ci.targets;
} emptyFile;
})