docs: create an automated changlog file that shows up in release files (#1793)

* docs: create an automated changlog file that shows up in release files
on  merge to develop/ami release success

* docs: changelog after release

* feat:
  1. Version check (.github/workflows/ami-release-nix.yml:110-120): After grabbing the release version, it checks if it matches the pattern
  ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]{3}(-orioledb)?$ and sets is_release output
  2. Generate Changelog (.github/workflows/ami-release-nix.yml:122-125): Only runs if is_release == 'true', uses --unreleased flag to generate changelog for commits
  since the last tag
  3. Commit and push (.github/workflows/ami-release-nix.yml:127-136): Commits the CHANGELOG.md to the repo and captures the new commit SHA
  4. Create release (.github/workflows/ami-release-nix.yml:189-195): Uses the changelog commit SHA as the target for releases, or falls back to the original SHA for
  non-release builds

* feat: start of actual changelog

* chore: remove extra chars from automated changelog

* chore: add base changelog

* chore: rm unreleased

Author: samrose

.github/workflows/ami-release-nix.yml

@@ -112,6 +112,30 @@ jobs:
         run: |
           VERSION=$(cat common-nix.vars.pkr.hcl | sed -e 's/postgres-version = "\(.*\)"/\1/g')
           echo "version=$VERSION" >> $GITHUB_OUTPUT
+          # Check if version matches release pattern
+          if echo "$VERSION" | grep -qE '^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]{3}(-orioledb)?$'; then
+            echo "is_release=true" >> $GITHUB_OUTPUT
+          else
+            echo "is_release=false" >> $GITHUB_OUTPUT
+          fi
+
+      - name: Generate Changelog
+        if: steps.process_release_version.outputs.is_release == 'true'
+        run: |
+          nix run nixpkgs#git-cliff -- --tag-pattern "^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]{3}(-orioledb)?$" --unreleased --tag "${{ steps.process_release_version.outputs.version }}" --prepend CHANGELOG.md
+          # Remove the changelog commit itself from the changelog
+          sed -i '/- Changelog after release/d' CHANGELOG.md
+
+      - name: Commit and push changelog
+        if: steps.process_release_version.outputs.is_release == 'true'
+        run: |
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git add CHANGELOG.md
+          git commit -m "docs: update changelog for ${{ steps.process_release_version.outputs.version }}"
+          git push
+          echo "changelog_commit=$(git rev-parse HEAD)" >> $GITHUB_OUTPUT
+        id: commit_changelog
 
       - name: Create nix flake revision tarball
         run: |
@@ -169,7 +193,8 @@ jobs:
         with:
           name: ${{ steps.process_release_version.outputs.version }}
           tag_name: ${{ steps.process_release_version.outputs.version }}
-          target_commitish: ${{github.sha}}
+          target_commitish: ${{ steps.process_release_version.outputs.is_release == 'true' && steps.commit_changelog.outputs.changelog_commit || github.sha }}
+          files: CHANGELOG.md
 
       - name: Slack Notification on Failure
         if: ${{ failure() }}