Simplify release process

This is now similar to the process used in rules_nixpkgs, releases are created from the master branch manually
by triggering the `Prepare Release` workflow. This workflow creates a draft release which just needs to be published
once it looks decent.

Author: avdv

.github/ISSUE_TEMPLATE/release.md

@@ -23,33 +23,15 @@ about: Steps to work through in order to publish a new release
   - [ ] Create "Added", "Removed", "Changed" and "Fixed" sections, as
         necessary.
   - [ ] If relevant, add links to the corresponding PRs to the entries.
-- [ ] Set the revision in [the `start` script][start] and
-      [`docs/haskell-use-cases`][usecases] to the current release
-      preparation branch; comment out the checksum. (n.b., Search for
-      `http_archive` in these files.)
 - [ ] Update the version of the modules in `MODULE.bazel` files
-- [ ] Push the `release-<major>.<minor>` branch and open a **draft** PR
-      to verify CI is green.
-- [ ] Create a release tag (`v<major>.<minor>`) on the release
-      preparation branch and push the tag; or use Github's UI.
-- [ ] Go to the [release page][releases]:
-    - [ ] Open the corresponding draft release and copy the workspace snippet.
-    - [ ] Insert the workspace snippet into [the `start` script][start]
-          and [`docs/haskell-use-cases`][usecases] replacing the existing snippet. 
-- [ ] Push the changes to the remote branch and mark the PR as ready;
-      go through review and merge to `master` upon success.
-  - If any changes need to be made, upon review, you will need to delete
-    the release tag (from local and origin) and repeat the previous four
-    steps appropriately before requesting a follow-up review.
-  - If there are changes on the release preparation branch that should
-    *not* go to `master`, create a second branch
-    `release-<major>.<minor>-master` on `master` and cherry-pick all
-    relevant commits from the release branch preparation branch. Open a
-    pull request with that branch, go through review and push changes
-    back to the release preparation branch.
-- [ ] Go to the [release page][releases]:
-    - [ ] Open the draft release for the current version.
-    - [ ] Release.
+- [ ] Push the `release-<major>.<minor>` branch and open a PR; go through review and merge upon success.
+- [ ] Trigger the `Prepare Release` workflow
+  - either via the Github UI **or**
+  - run `gh workflow run -f version=<major>.<minor> 'Prepare Release'` using the Github CLI
+- [ ] Go to the [releases], open the draft release which was created to inspect it
+  - Do the code snippets look valid?
+  - Is there a release artifact attached to it?
+  - If you're happy, publish the release... :rocket:
 - [ ] After the "Publish" workflow is finished check whether https://haskell.build/start
       is now the latest [`start` script][start] (Netlify sometimes has problems).
 - [ ] Announce the new version on Twitter by asking someone with access.

.github/workflows/publish.yaml

@@ -2,7 +2,7 @@ name: Publish
 
 on:
   release:
-    types: [published]
+    types: [released]
   workflow_dispatch: # allows manual triggering
 
 jobs:
@@ -21,5 +21,39 @@ jobs:
           git config user.email [email protected]
       - name: Merge master into release
         run: git merge --no-edit origin/master
-      - name: Push
-        run: git push
+      - name: Fetch latest release artifact
+        id: latest
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          gh release download -p '*.tar.gz' -D release
+          ls release | sed -ne 's/rules_haskell-\(.*\)[.]tar[.]gz/version=\1/p' >> "${GITHUB_OUTPUT}"
+          shasum -a 256 release/*.tar.gz | awk '{print "hash=" $1}' >> "${GITHUB_OUTPUT}"
+      - name: Update hash in start script and docs
+        run: |
+          sed -i \
+             -e '/bazel_dep(name = "rules_haskell"/s/version = "[^"]*"/version = "${{ steps.latest.outputs.version }}"/' \
+             start
+          # update http_archive attrs between `cat > WORKSPACE` and `EOF`
+          sed -i \
+             -e '/cat > WORKSPACE/,/^EOF/{' \
+             -e '  s%sha256 = "[^"]*"%sha256 = "${{ steps.latest.outputs.hash }}"%; ' \
+             -e '  s%strip_prefix = "[^"]*"%strip_prefix = "rules_haskell-${{ steps.latest.outputs.version }}"%; ' \
+             -e '  s%url = "[^"]*"%url = "https://github.com/tweag/rules_haskell/releases/download/v${{ steps.latest.outputs.version }}/rules_haskell-${{ steps.latest.outputs.version }}.tar.gz"%' \
+             -e '}' \
+             start
+          # update http_archive attrs in docs between `name = "rules_haskell"` and `url = "`
+          sed -i \
+             -e '/name = "rules_haskell"/,/url = "/{' \
+             -e '  s%sha256 = "[^"]*"%sha256 = "${{ steps.latest.outputs.hash }}"%; ' \
+             -e '  s%strip_prefix = "[^"]*"%strip_prefix = "rules_haskell-${{ steps.latest.outputs.version }}"%; ' \
+             -e '  s%url = "[^"]*"%url = "https://github.com/tweag/rules_haskell/releases/download/v${{ steps.latest.outputs.version }}/rules_haskell-${{ steps.latest.outputs.version }}.tar.gz"%; ' \
+             -e '}' \
+             docs/haskell-use-cases.rst
+      - name: Commit and Push
+        run: |
+          if ! git diff --exit-code ; then
+            git add start docs/haskell-use-cases.rst
+            git commit -m "Update rules_haskell in start script and docs to version ${{ steps.latest.outputs.version }}"
+            git push
+          fi