contributing: Generate ChangeLog in release workflow (#2402)

The ChangeLog file uploaded with the tarball is now generated in the create release draft workflow and added to the release. From there it is retrieved in the release workflow and a version-specific name is used for it.

Fetch all history in the workflow to get a correct log.

.github/workflows/create_release_draft.yml

@@ -22,6 +22,8 @@ jobs:
     steps:
       - name: Checks-out repository
         uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
 
       - name: Set up Python
         uses: actions/setup-python@v2
@@ -34,6 +36,12 @@ jobs:
           git add core_modules_with_last_commit.json
           git diff --cached > core_modules_with_last_commit.patch
 
+      - name: Generate ChangeLog file
+        run: |
+          sudo apt-get install -y gzip
+          python utils/gitlog2changelog.py
+          gzip ChangeLog
+
       - name: Create new release draft (for tags only)
         id: create_release
         if: startsWith(github.ref, 'refs/tags/')
@@ -72,12 +80,24 @@ jobs:
           asset_name: core_modules_with_last_commit.patch
           asset_content_type: text/plain
 
+      - name: Upload ChangeLog file (for tags only)
+        if: startsWith(github.ref, 'refs/tags/')
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+        with:
+          upload_url: ${{ steps.create_release.outputs.upload_url }}
+          asset_path: ChangeLog.gz
+          asset_name: ChangeLog.gz
+          asset_content_type: application/gzip
+
       - name: Make the created files available
         uses: actions/upload-artifact@v3
         if: always()
         with:
           name: artifacts
           path: |
             core_modules_with_last_commit.*
+            ChangeLog.gz
           if-no-files-found: warn
           retention-days: 10

doc/howto_release.md

@@ -269,16 +269,14 @@ Confirm the version (it should match exactly the tag specified above):
 echo "$VERSION"
 ```
 
-### Create a changelog file
+### Get changelog file for upload
 
 There is also a large changelog file we produce and publish,
-create it with a script (it takes several minutes to complete):
+fetch the file from the release which was generated by a workflow
+linked to the tag:
 
 ```bash
-python3 utils/gitlog2changelog.py
-mv ChangeLog ChangeLog_$VERSION
-head ChangeLog_$VERSION
-gzip ChangeLog_$VERSION
+wget https://github.com/OSGeo/grass/releases/download/${VERSION}/ChangeLog.gz -O ChangeLog_${VERSION}.gz
 ```
 
 ### Get the source code tarball