Improve BCR release process (#301)

- New workflow to create release tag (Yes I know, but it seemed trivial
enough to add.)
- New workflow to create draft release
- BCR release prep script, adds Bazel snippets to release notes like
other Bazel projects, creates stable release tarball

This should take care of the issues we have with the BCR publishing
process, I think.

.bcr/source.template.json

@@ -1,5 +1,5 @@
 {
   "integrity": "",
   "strip_prefix": "{REPO}-{VERSION}",
-  "url": "https://github.com/{OWNER}/{REPO}/archive/refs/tags/{TAG}.tar.gz"
+  "url": "https://github.com/{OWNER}/{REPO}/releases/download/{TAG}/{REPO}-{VERSION}.tar.gz"
 }

.github/workflows/create-release-draft.yaml

@@ -0,0 +1,39 @@
+name: Create release draft
+
+on:
+  workflow_call:
+    inputs:
+      tag_name:
+        description: Tag to create a release for.
+        required: true
+        type: string
+  workflow_dispatch:
+    inputs:
+      tag_name:
+        description: Tag to create a release for.
+        required: true
+        type: string
+  push:
+    tags:
+      - v*
+
+jobs:
+  create-release-draft:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.inputs.tag_name || github.ref_name }}
+      - name: Create release tarball
+        run: .github/workflows/release_prep.sh ${{ github.event.inputs.tag_name || github.ref_name }}
+      - name: Release
+        uses: softprops/action-gh-release@v2
+        with:
+          draft: true
+          tag_name: ${{ github.event.inputs.tag_name || github.ref_name }}
+          body_path: release_notes.md
+          generate_release_notes: true
+          files: |
+            protovalidate-*.tar.gz
+

.github/workflows/create-release-tag.yaml

@@ -0,0 +1,60 @@
+name: Create release tag
+
+on:
+  workflow_dispatch:
+    inputs:
+      tag_name:
+        description: 'Tag name for release (e.g. "v1.0.0")'
+        required: true
+
+permissions:
+  contents: write
+
+jobs:
+  create-release-tag:
+    name: Create release tag
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Create tag
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const tag = '${{ github.event.inputs.tag_name }}';
+            const toolsTag = `tools/${tag}`;
+            const commitTag = await github.rest.git.createTag({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              tag,
+              message: tag,
+              object: context.sha,
+              type: 'commit',
+            });
+            const toolsCommitTag = await github.rest.git.createTag({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              tag: toolsTag,
+              message: toolsTag,
+              object: context.sha,
+              type: 'commit',
+            });
+            await github.rest.git.createRef({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              ref: `refs/tags/${tag}`,
+              sha: commitTag.data.sha,
+            });
+            await github.rest.git.createRef({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              ref: `refs/tags/${toolsTag}`,
+              sha: toolsCommitTag.data.sha,
+            });
+
+  create-release-draft:
+    name: Start release automation
+    uses: ./.github/workflows/create-release-draft.yaml
+    with:
+      tag_name: ${{ github.event.inputs.tag_name }}

.github/workflows/release_prep.sh

@@ -0,0 +1,72 @@
+#!/bin/bash
+set -x -e -u -o pipefail
+
+if [[ $# -ne 1 ]]; then
+    >&2 echo "Usage: ${0} <version tag>"
+    exit 1
+fi
+
+NAME="protovalidate"
+TAG="${1}"
+PREFIX="${NAME}-${TAG:1}"
+ARCHIVE="${PREFIX}.tar.gz"
+
+# Update MODULE.bazel version
+>&2 echo "# Update MODULE.bazel version to ${TAG:1}"
+if ! awk -v tag="${TAG:1}" '
+    sub(/version = "0\.0\.0",/, "version = \"" tag "\",") {
+        count++;
+    }
+    { print; }
+    END {
+        if (count != 1) {
+            exit 1;
+        }
+    }
+' MODULE.bazel > MODULE.bazel.tmp; then
+    >&2 echo "Failed to update MODULE.bazel version!"
+    rm MODULE.bazel.tmp
+    exit 1
+fi
+
+mv MODULE.bazel.tmp MODULE.bazel
+>&2 echo "MODULE.bazel contents:"
+cat MODULE.bazel
+
+# Create release archive
+>&2 echo "# Create release archive ${ARCHIVE}"
+git archive \
+    --prefix="${PREFIX}/" \
+    --output="${ARCHIVE}" \
+    "$(git stash create)"
+
+>&2 echo "Release archive ${ARCHIVE} contents:"
+tar tvf "${ARCHIVE}"
+
+# Calculate SHA256 sum for WORKSPACE code
+SHA256=$(shasum -a 256 "${ARCHIVE}" | awk '{print $1}')
+
+# Generate release notes snippets
+>&2 echo "# Generate release notes snippets"
+> release_notes.md cat << EOF
+## \`MODULE.bazel\` Usage
+\`\`\`bzl
+bazel_dep(name = "protovalidate", version = "${TAG:1}")
+\`\`\`
+
+## \`WORKSPACE\` Usage
+\`\`\`bzl
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+http_archive(
+    name = "com_github_bufbuild_protovalidate",
+    sha256 = "${SHA256}",
+    strip_prefix = "${PREFIX}",
+    urls = [
+        "https://github.com/bufbuild/protovalidate/releases/download/${TAG}/protovalidate-${TAG}.tar.gz",
+    ],
+)
+\`\`\`
+EOF
+
+>&2 echo "Success."

.gitignore

@@ -3,3 +3,5 @@
 *.svg
 cover.out
 /bazel-*
+/protovalidate-*.tar.gz
+/release_notes.md

MODULE.bazel

@@ -14,7 +14,7 @@
 
 module(
     name = "protovalidate",
-    version = "0.10.0",
+    version = "0.0.0",
     repo_name = "com_github_bufbuild_protovalidate",
 )
 

RELEASING.md

@@ -0,0 +1,83 @@
+# Releasing protovalidate
+
+The protovalidate repository contains two Go modules, and a Bazel module with
+Bzlmod and WORKSPACE support, which is pushed to the Bazel Central Repository.
+Proper release process is necessary to ensure that a protovalidate release is
+usable in all of these forms.
+
+Most of the protovalidate release process is automated, but in the event that
+automation can not be utilized, the manual steps are also included in the
+collapsed sections below.
+
+1.  **Run the [create release tag] workflow.**
+
+    Go to the [create release tag] workflow page and select <q>Run workflow</q>,
+    with the desired version tag (e.g. `v1.2.3`).
+
+    <details>
+
+    <summary>What this workflow does</summary>
+
+    This will create two release tags for the latest `main` revision:
+
+    - `v1.2.3`: For Bazel, BCR, Go main module, etc.
+    - `tools/v1.2.3`: For the Go tools module
+
+    These tags can also be created manually. Pushing the `v1.2.3` tag should
+    trigger the remaining release automation. Do not forget to create both tags
+    in the event of manually cutting a release.
+
+    Note that this workflow creates tags directly on GitHub instead of pushing
+    tags up, so it will not indirectly trigger the draft release automation in
+    that way. Instead, a workflow call is used. So, the creat release draft
+    workflow will appear nested under the create release tag workflow as a step.
+
+    </details>
+
+1.  **Find the draft release.**
+
+    Upon either pushing a release tag or running the previous workflow, a
+    release draft should be created. Check for it in the [releases page].
+
+    If for some reason this doesn't happen, it is possible to directly trigger
+    the workflow by going to the [create release draft] action and selecting
+    <q>Run workflow</q>.
+
+    <details>
+
+    <summary>Manually creating a release draft</summary>
+
+    To manually create a release draft, run `.github/workflows/release_prep.sh`
+    with the version tag (e.g. `vX.Y.Z`) as an argument, while checked out to
+    the release tag/commit:
+
+    ```
+    .github/workflows/release_prep.sh v1.2.3
+    ```
+
+    This will create two files:
+
+    - `release_notes.md`: This should be prepended to the GitHub-generated
+      release notes. It contains instructions on how to include the repo with
+      Bazel.
+    - `protovalidate-1.2.3.tar.gz`: This should be attached to the release. It
+      includes a stable tarball of the release commit for Bazel.
+
+    </details>
+
+1.  **Publish the release.**
+
+    Once the release draft is created, edit it as needed, prepending any
+    important notes (e.g. breaking changes), and finally, publish it.
+
+1.  **Check [Bazel Central Registry repository] for a pull request.**
+
+    Shortly after publishing the release, the [Publish to BCR] app should've
+    created a new pull request. There may be failures in CI that need to be
+    addressed.
+
+[create release tag]: https://github.com/bufbuild/protovalidate/actions/workflows/create-release-tag.yaml
+[create release draft]: https://github.com/bufbuild/protovalidate/actions/workflows/create-release-draft.yaml
+[releases page]: https://github.com/bufbuild/protovalidate/releases
+[Bazel Central Registry repository]: https://github.com/bazelbuild/bazel-central-registry/pulls
+[Publish to BCR]: https://github.com/apps/publish-to-bcr