feat: update release process to add full tarball

Github asset does not contain submodule code, we manually create the git
archive with all submodules sources checked out to be used as a self
contained bazel module.

Author: GuillaumeLagrange

CONTRIBUTING.md

@@ -2,6 +2,11 @@
 
 ## Release
 
-For now, releasing is done manually, by tagging a git rev with vX.Y.Z.
+To create a release, follow these steps:
 
-When releasing a new version, please make sure the version is updated in the [`core/CMakeLists.txt`](https://github.com/CodSpeedHQ/codspeed-cpp/blob/main/core/CMakeLists.txt#L3) and [`core/BUILD`](https://github.com/CodSpeedHQ/codspeed-cpp/blob/main/core/BUILD#L4) files to match the pushed version
+1. Update the version in the following locations to the new version:
+    - [`core/CMakeLists.txt`](https://github.com/CodSpeedHQ/codspeed-cpp/blob/main/core/CMakeLists.txt#L3) 
+    - [`core/MODULE.bazel`](https://github.com/CodSpeedHQ/codspeed-cpp/blob/main/core/MODULE.bazel#3)
+    - [`google_benchmark/MODULE.bazel` module's version](https://github.com/CodSpeedHQ/codspeed-cpp/blob/main/google_benchmark/MODULE.bazel#L3)
+    - [`google_benchmark/MODULE.bazel` core dependency version](https://github.com/CodSpeedHQ/codspeed-cpp/blob/main/google_benchmark/MODULE.bazel#L6)
+2. Once the version changes are merged on main, run `scripts/release.sh <new_version>` to tag and create the release on GitHub.

flake.nix

@@ -21,6 +21,7 @@
         commonBuildInputs = with pkgs; [
           gcc
           pkg-config
+          git-cliff
 
           # Build systems
           cmake

scripts/release.sh

@@ -24,10 +24,42 @@ if [ -z "$GITHUB_TOKEN" ]; then
 
 fi
 
+# Make sure submodules are up to date
+git submodule update --init --recursive
+
+# Check that no uncommitted changes exist
+if [ -n "$(git status --porcelain)" ]; then
+    echo "Uncommitted changes exist. Please commit or stash them before creating a release."
+    exit 1
+fi
+
 git cliff -o CHANGELOG.md --tag $VERSION --github-token $GITHUB_TOKEN
 git add CHANGELOG.md
 git commit -m "chore: Release $VERSION"
 git tag $VERSION -m "Release $VERSION"
 git push origin main
 git push origin $VERSION
-gh release create $VERSION -t $VERSION --generate-notes -d
+
+# Create tarball with submodules included
+echo "Creating release tarball with submodules..."
+TMPDIR=$(mktemp -d)
+ARCHIVE_NAME="codspeed-cpp-${VERSION}"
+TARBALL_NAME="${ARCHIVE_NAME}.tar.gz"
+
+# Create main archive
+git archive --prefix="${ARCHIVE_NAME}/" --format=tar HEAD | \
+  (cd "$TMPDIR" && tar xf -)
+
+# Add submodule content
+git submodule foreach --recursive "git archive --prefix=${ARCHIVE_NAME}/\$path/ --format=tar HEAD | (cd $TMPDIR && tar xf -)"
+
+# Create final tarball
+(cd "$TMPDIR" && tar czf "$TMPDIR/$TARBALL_NAME" "$ARCHIVE_NAME")
+
+echo "Tarball created at: $TMPDIR/$TARBALL_NAME"
+
+# Create GitHub release with the tarball
+gh release create $VERSION -t $VERSION --generate-notes -d "$TMPDIR/$TARBALL_NAME"
+
+# Cleanup
+rm -rf "$TMPDIR"