feat(ci): report package sizes

Added as a comment to the current pull request

.forgejo/workflows/check.yml

@@ -3,12 +3,15 @@ on:
 jobs:
   check:
     runs-on: nixos
+    needs: build
     steps:
       - uses: "https://code.forgejo.org/actions/checkout@v4"
       - run: nix --version
-      - run: nix flake check --keep-going --verbose
+      - name: Run Checks
+        run: nix flake check --keep-going --verbose
   build:
     runs-on: nixos
+    if: github.event_name == 'push'
     strategy:
       matrix:
         target:
@@ -20,4 +23,13 @@ jobs:
     steps:
       - uses: "https://code.forgejo.org/actions/checkout@v4"
       - run: nix --version
-      - run: nix build --print-build-logs '.#${{ matrix.target }}'
+      - name: Build target
+        run: nix build --print-build-logs '.#${{ matrix.target }}'
+  report-size:
+    runs-on: nixos
+    needs: build
+    steps:
+      - uses: "https://git.salame.cl/actions/checkout@v4"
+      - run: nix --version
+      - name: Report Size
+        run: ci-scripts/report-size.sh

.gitignore

@@ -1,4 +1,5 @@
 result
+result-*
 .direnv/
 .pre-commit-config.yaml
 # ignore vm images

ci-scripts/report-size.sh

@@ -0,0 +1,102 @@
+#!/bin/sh
+
+set -eu
+
+echo 'Retrieving Flake information' >&2
+flake_info=$(nix flake show --json 2>/dev/null)
+packages=$(
+	jq --raw-output '.packages."x86_64-linux" | keys[]' <<-EOF
+		$flake_info
+	EOF
+)
+echo "Packages:" >&2
+echo "$packages" >&2
+configurations=$(
+	jq --raw-output '.nixosConfigurations | keys[]' <<-EOF
+		$flake_info
+	EOF
+)
+echo "NixOS Configurations:" >&2
+echo "$configurations" >&2
+
+package_size_table() {
+	table='| Installable | NAR Size | Closure Size |
+|-------------|---------:|-------------:|
+'
+	for package in $packages; do
+		echo "Building $package" >&2
+		path=$(nix build --print-out-paths ".#$package" 2>/dev/null)
+		echo "Calculating size of $package" >&2
+		row=$(nix path-info --size --closure-size --human-readable "$path" 2>/dev/null |
+			sed "s/^\(\S\+\)\(\s\+\)\(\S\+\)\(\s\+\)\(\S\+\)$/| \`$package\` | \3 | \5 |/")
+		table="$table$row
+"
+	done
+
+	printf '%s' "$table"
+}
+
+configuration_size_table() {
+	table='| NixOS Configuration | NAR Size | Closure Size |
+|-------------|---------:|-------------:|
+'
+	for config in $configurations; do
+		echo "Building $config" >&2
+		path=$(nix build --print-out-paths ".#nixosConfigurations.$config.config.system.build.toplevel" 2>/dev/null)
+		echo "Calculating size of $config" >&2
+		row=$(nix path-info --size --closure-size --human-readable "$path" 2>/dev/null |
+			sed "s/^\(\S\+\)\(\s\+\)\(\S\+\)\(\s\+\)\(\S\+\)$/| \`$config\` | \3 | \5 |/")
+		table="$table$row
+"
+	done
+
+	printf '%s' "$table"
+}
+
+markdown() {
+	cat <<-EOF
+		## Outputs' size
+
+		### NixOS Configurations sizes
+
+		$(configuration_size_table)
+
+
+		### Package sizes
+
+		$(package_size_table)
+	EOF
+}
+
+if [ "${CI-false}" = "true" ]; then
+	pr_number=$(curl -X 'GET' \
+		"$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/pulls?state=open&sort=recentupdate" \
+		-H 'accept: application/json' |
+		jq --arg head_ref "$GITHUB_REF_NAME" '.[] | select(.head.ref == $head_ref) | .number')
+
+	if [ -z "$pr_number" ]; then
+		echo "No PR created for this commit"
+		exit 0
+	fi
+
+	echo "Retrieved index: $pr_number" >&2
+	echo "Expected PR URL: $GITHUB_SERVER_URL/$GITHUB_REPOSITORY/pulls/$pr_number" >&2
+
+	echo 'Generating comment body' >&2
+	comment=$(markdown)
+
+	echo 'Posting comment:' >&2
+	echo "$comment" >&2
+
+	echo 'Request data:' >&2
+	data=$(echo '{}' | jq --arg comment "$comment" '.body=$comment')
+	echo "$data" >&2
+	curl -o - -X 'POST' \
+		"$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/issues/$pr_number/comments" \
+		-H 'accept: application/json' \
+		-H "Authorization: token $GITHUB_TOKEN" \
+		-H 'Content-Type: application/json' \
+		-d "$data"
+else
+	markdown
+fi