Automated releases

.github/workflows/main.yml

@@ -3,9 +3,6 @@ on:
   pull_request:
     branches:
       - main
-  push:
-    branches:
-      - main
 
 jobs:
   check:

.github/workflows/release.yml

@@ -0,0 +1,16 @@
+name: CD
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: cachix/install-nix-action@v26
+
+      - name: release
+        run: scripts/release.sh

package.nix

@@ -13,9 +13,11 @@
 }:
 let
   fs = lib.fileset;
+  version = (builtins.fromTOML (builtins.readFile ./Cargo.toml)).package.version;
 in
 rustPlatform.buildRustPackage {
-  name = "nixpkgs-check-by-name";
+  pname = "nixpkgs-check-by-name";
+  inherit version;
   src = fs.toSource {
     root = ./.;
     fileset = fs.unions [

scripts/release.sh

@@ -0,0 +1,103 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+tmp=$(mktemp -d)
+trap 'rm -rf "$tmp"' exit
+
+nixeval() {
+  # Since there's no stable `nix eval --raw`, also see https://github.com/NixOS/nix/pull/9361
+  nix-instantiate --eval --json "$@" | jq -r .
+}
+
+# The system to pre-build the release for and distribute artifacts for
+system=x86_64-linux
+root=$(git rev-parse --show-toplevel)
+repository=${GITHUB_REPOSITORY:-NixOS/nixpkgs-check-by-name}
+
+# Get the version from the Cargo.toml file
+version=$(nixeval "$root" -A build.version)
+echo "Current version is $version"
+
+if existingRelease=$(gh api \
+  -H "Accept: application/vnd.github+json" \
+  -H "X-GitHub-Api-Version: 2022-11-28" \
+  /repos/"$repository"/releases/tags/"$version"); then
+  echo "Release $version already exists, no new release necessary"
+  exit 0
+else
+  echo "$existingRelease"
+  echo "Release $version doesn't exist yet, creating it"
+fi
+
+echo "Building release artifact for system $system"
+
+nix-build "$root" -A build -o "$tmp/build" >/dev/null
+readarray -t closure < <(nix-store -qR "$tmp/build")
+nix-store --export "${closure[@]}" > "$tmp/$system.nar"
+gzip "$tmp/$system.nar"
+artifactName=$system.nar.gz
+
+body='Automated release.
+
+The artifact is a gzip-compressed [Nix Archive](https://nixos.org/manual/nix/stable/command-ref/nix-store/export.html) of the [build closure](https://nixos.org/manual/nix/stable/glossary#gloss-closure).
+
+To import it:
+```bash
+gzip -cd '"$artifactName"' | nix-store --import | tail -1
+```
+'
+
+echo "Creating draft release"
+if ! release=$(gh api \
+  --method POST \
+  -H "Accept: application/vnd.github+json" \
+  -H "X-GitHub-Api-Version: 2022-11-28" \
+  /repos/"$repository"/releases \
+  -f tag_name="$version" \
+  -f name="Version $version" \
+  -f body="$body" \
+  -F draft=true); then
+  echo "Failed to create release: $release"
+fi
+
+releaseId=$(jq .id <<< "$release")
+
+abortRelease() {
+  echo "Aborting, deleting the draft release"
+  gh api \
+    --method DELETE \
+    -H "Accept: application/vnd.github+json" \
+    -H "X-GitHub-Api-Version: 2022-11-28" \
+    /repos/"$repository"/releases/"$releaseId"
+  exit 1
+}
+
+echo "Uploading release artifact"
+# GitHub docs say to use the releases' upload_url, but that's of the RFC 6570 form, see
+# https://docs.github.com/en/rest/using-the-rest-api/getting-started-with-the-rest-api?apiVersion=2022-11-28#hypermedia
+# And neither the GitHub CLI nor curl seem to have support for that right now, so let's do it
+# manually instead
+if ! uploadResult=$(curl -sSfL \
+  -X POST \
+  -H "Accept: application/vnd.github+json" \
+  -H "Authorization: Bearer $(gh auth token)" \
+  -H "X-GitHub-Api-Version: 2022-11-28" \
+  -H "Content-Type: application/octet-stream" \
+  "https://uploads.github.com/repos/$repository/releases/$releaseId/assets?name=$artifactName" \
+  --data-binary "@$tmp/$artifactName"); then
+  echo "Failed to upload artifact: $uploadResult"
+  abortRelease
+fi
+
+if ! publishResult=$(gh api \
+  --method PATCH \
+  -H "Accept: application/vnd.github+json" \
+  -H "X-GitHub-Api-Version: 2022-11-28" \
+  /repos/"$repository"/releases/"$releaseId" \
+  -F draft=false); then
+  echo "Failed to publish release: $publishResult"
+  abortRelease
+fi
+
+echo "Published release: $(jq .html_url -r <<< "$publishResult")"