tvl-depot/default.nix
Vincent Ambo d7b89df748 feat(ops/pipelines): Add gcroots for depot builds on canon
Adds a conditional build step that only runs on the canon branch, and
only if 🦆 (the status reporting step) succeeds, which creates a
new Nix GC root for all depot targets named `depot-canon`.

In practice this might be a bit racey, as canon builds are not
guaranteed to succeed in order (though it is likely). This shouldn't
matter much in practice: We only want to prevent rebuilds of the whole
world.

This fixes b/102

Change-Id: Id3d0bf4158bffcb1ed6929888a29d31609b6ece1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2904
Tested-by: BuildkiteCI
Reviewed-by: glittershark <grfn@gws.fyi>
2021-04-11 20:09:53 +00:00

118 lines
3.8 KiB
Nix

# This file sets up the top-level package set by traversing the package tree
# (see read-tree.nix for details) and constructing a matching attribute set
# tree.
#
# This makes packages accessible via the Nixery instance that is configured to
# use this repository as its nixpkgs source.
{ nixpkgsBisectPath ? null, ... }@args:
with builtins;
let
# This definition of fix is identical to <nixpkgs>.lib.fix, but the global
# package set is not available here.
fix = f: let x = f x; in x;
# Global configuration that all packages are called with.
config = depot: {
inherit depot;
# Expose lib attribute to packages.
inherit (depot.third_party.nixpkgs) lib;
# Pass third_party as 'pkgs' (for compatibility with external
# imports for certain subdirectories)
pkgs = depot.third_party.nixpkgs;
# 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;
};
readTree' = import ./nix/readTree {};
localPkgs = readTree: {
fun = readTree ./fun;
lisp = readTree ./lisp;
net = readTree ./net;
nix = readTree ./nix;
ops = readTree ./ops;
third_party = readTree ./third_party;
tools = readTree ./tools;
tvix = readTree ./tvix;
users = readTree ./users;
web = readTree ./web;
};
# 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);
# Walk the tree starting with 'node', recursively extending the list
# of build targets with anything that looks buildable.
#
# Any tree node can specify logical targets by exporting a
# 'meta.targets' attribute containing a list of keys in itself. This
# enables target specifications that do not exist on disk directly.
gather = node:
if node ? __readTree then
# Include the node itself if it is eligible.
(if eligible node then [ node ] else [])
# Include eligible children of the node
++ concatMap gather (attrValues node)
# Include specified sub-targets of the node
++ filter eligible (map
(k: (node."${k}" or {}) // {
# Keep the same tree location, but explicitly mark this
# node as a subtarget.
__readTree = node.__readTree;
__subtarget = k;
})
(node.meta.targets or []))
else [];
in fix(self: {
__readTree = [];
config = config self;
# Expose readTree for downstream repo consumers.
readTree = {
__functor = x: (readTree' x.config);
config = self.config;
};
# Make the path to the depot available for things that might need it
# (e.g. NixOS module inclusions)
depotPath = ./.;
# 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 = gather (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 = self.third_party.nixpkgs.symlinkJoin {
name = "depot-gcroot";
paths = self.ci.targets;
};
}
# Add local packages as structured by readTree
// (localPkgs (readTree' self.config))
)