Add a workflow looking for changelog fragments

Closes:: #186

.github/workflows/fragment.yml

@@ -0,0 +1,18 @@
+---
+on: 
+  pull_request:
+
+name: Check changelog fragment
+jobs:
+  check_fragment:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+
+    - name: Automatic Rebase
+      run: ./hacking/check_fragment.sh
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        PR_NUMBER: ${{ github.event.number }}

README.md

@@ -182,6 +182,7 @@ See LICENCE to see the full text.
 
 Any contribution is welcome and we only ask contributors to:
 * Provide *at least* integration tests for any contribution.
+* The Pull Request *MUST* contain a changelog fragment. See [Ansible documentation](https://docs.ansible.com/ansible/latest/community/development_process.html#creating-a-changelog-fragment) about fragments.
 * Create an issue for any significant contribution that would change a large portion of the code base.
 
 ## Contributors ✨

hacking/NEED_FRAGMENT

@@ -0,0 +1,7 @@
+Dear contributor,
+
+Thank you for you Pull Request !
+To ease the work of maintainers you need to add a [changelog fragment](https://docs.ansible.com/ansible/latest/community/development_process.html#creating-a-changelog-fragment) in you PR.
+
+It will help your change be released faster !
+Thank you !

hacking/check_fragment.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+
+function comment() {
+    echo "No fragment detected"
+    if [ -n "$PR_NUMBER" ]; then
+        gh pr review $PR_NUMBER -r -F $(git rev-parse --show-toplevel)/hacking/NEED_FRAGMENT
+    fi
+    exit 1
+}
+
+function approve() {
+    if [ -n "$PR_NUMBER" ]; then
+        gh pr review $PR_NUMBER -a
+    fi
+}
+
+if [ -z "$GITHUB_BASE_REF" ]; then
+    GITHUB_BASE_REF="origin/main"
+fi
+
+echo "Comparing HEAD with $GITHUB_BASE_REF"
+
+FRAGMENTS=$(git diff --name-only --diff-filter=ACMRT $GITHUB_BASE_REF..HEAD | grep "changelogs/fragments")
+
+if [ -z "$FRAGMENTS" ]; then
+    comment
+else
+    aprove
+fi