Add a single commit check workflow

[noissue]

.github/workflows/check_commits.yaml

@@ -2,6 +2,19 @@
 name: Check Commit
 on: pull_request
 jobs:
+  single_commit:
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v1
+      with:
+        fetch-depth: 30
+    - name: Checkout master
+      run: git fetch origin master
+    - name: create local master branch
+      run: git branch master origin/master
+    - name: Commit Count Check
+      run: test `git log  --oneline --no-merges HEAD ^master  | wc -l ` = 1
+    runs-on: ubuntu-latest
   test:
     runs-on: ubuntu-latest
     steps:

CHANGES/tba.feature

@@ -0,0 +1 @@
+Added a workflow to check that PRs contain a single commit.

README.md

@@ -209,6 +209,8 @@ The following settings are stored in `template_config.yml`.
 
   noissue_marker        A string that is used to mark a commit as not attached to an issue.
 
+  single_commit_check   Runs a workflow to indicate whether a PR contains a single commit or not.
+
   sync_ci               Enables a nightly workflow to update the CI files.
 
   test_bindings         Include a job that runs a script to test generated client

templates/github/.ci/scripts/discourse_post.sh

@@ -0,0 +1,24 @@
+#!/bin/bash
+
+# Posts a release announcement to discourse
+
+URL="https://discourse.pulpproject.org/posts.json"
+CATEGORY=1 # Announcements
+DISCOURSE_USER="system"
+
+plugin="$1"
+version="$2"
+body = $(cat <<-EOM
+$plugin $version has been released.
+
+PyPI: https://pypi.org/project/$plugin/$version/
+Changelog: Changelog — Pulp File 1.9.1 documentation
+Docs: pulp_file Plugin — Pulp File 1.9.1 documentation
+Python bindings: pulp-file-client · PyPI
+Ruby bindings: pulp_file_client | RubyGems.org | your community gem host
+EOM
+
+curl -X POST "$URL"
+    -H "Api-Key: $DISCOURSE_TOKEN"
+    -H "Api-Username: $DISCOURSE_USER"
+    -H "title: $1 $2 has been released"

templates/github/.github/workflows/single_commit.yml.j2

@@ -0,0 +1,24 @@
+name: Assert Single Commit
+
+on:
+  {%- if single_commit_check -%}
+  pull_request:
+    branches: [ {{ plugin_default_branch }} ]
+  {%- else -%}
+  workflow_dispatch: # don't run
+  {%- endif -%}
+
+jobs:
+  single_commit:
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v1
+      with:
+        fetch-depth: 30
+    - name: Checkout {{ plugin_default_branch }}
+      run: git fetch origin {{ plugin_default_branch }}
+    - name: create local {{ plugin_default_branch }} branch
+      run: git branch {{ plugin_default_branch }} origin/{{ plugin_default_branch }}
+    - name: Commit Count Check
+      run: test `git log  --oneline --no-merges HEAD ^{{ plugin_default_branch }}  | wc -l ` = 1
+    runs-on: ubuntu-latest