Add a single commit check workflow

.github/workflows/check_commits.yaml

@@ -2,6 +2,20 @@
 name: Check Commit
 on: pull_request
 jobs:
+  single_commit:
+    name: Assert 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/494.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 job to check 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

plugin-template

@@ -60,6 +60,7 @@ DEFAULT_SETTINGS = {
     "release_user": "pulpbot",
     "release_email": "[email protected]",
     "noissue_marker": "[noissue]",
+    "single_commit_check": True,
     "sync_ci": True,
     "test_bindings": True,
     "test_cli": False,

templates/github/.github/workflows/ci.yml.j2

@@ -17,6 +17,23 @@ jobs:
 
 {% if pre_job_template -%}{{ "  " | indent }}{% include pre_job_template.path %}{%- endif %}
 
+  {%- if single_commit_check %}
+  single_commit:
+    name: Assert 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
+  {%- endif %}
+
   lint:
     runs-on: ubuntu-latest
     {% if pre_job_template %}needs: {{ pre_job_template.name }}{% endif %}