tvl-depot/tools/nixery/build-image/load-pkgs.nix
Vincent Ambo 980f5e2187 refactor(server): Move package source management logic to server
Introduces three new types representing each of the possible package
sources and moves the logic for specifying the package source to the
server.

Concrete changes:

* Determining whether a specified git reference is a commit vs. a
  branch/tag is now done in the server, and is done more precisely by
  using a regular expression.

* Package sources now have a new `CacheKey` function which can be used
  to retrieve a key under which a build manifest can be cached *if*
  the package source is not a moving target (i.e. a full git commit
  hash of either nixpkgs or a private repository).

  This function is not yet used.

* Users *must* now specify a package source, Nixery no longer defaults
  to anything and will fail to launch if no source is configured.
2019-09-10 11:32:37 +01:00

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1.7 KiB
Nix

# Copyright 2019 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# Load a Nix package set from one of the supported source types
# (nixpkgs, git, path).
{ srcType, srcArgs, importArgs ? { } }:
with builtins;
let
# If a nixpkgs channel is requested, it is retrieved from Github (as
# a tarball) and imported.
fetchImportChannel = channel:
let
url =
"https://github.com/NixOS/nixpkgs-channels/archive/${channel}.tar.gz";
in import (fetchTarball url) importArgs;
# If a git repository is requested, it is retrieved via
# builtins.fetchGit which defaults to the git configuration of the
# outside environment. This means that user-configured SSH
# credentials etc. are going to work as expected.
fetchImportGit = spec: import (fetchGit spec) importArgs;
# No special handling is used for paths, so users are expected to pass one
# that will work natively with Nix.
importPath = path: import (toPath path) importArgs;
in if srcType == "nixpkgs" then
fetchImportChannel srcArgs
else if srcType == "git" then
fetchImportGit (fromJSON srcArgs)
else if srcType == "path" then
importPath srcArgs
else
throw ("Invalid package set source specification: ${srcType} (${srcArgs})")