Ability to template path of published badge

README.md

@@ -4,6 +4,10 @@
 
 A Cloud Function that generates Cloud Build badges.
 
+## Summary
+
+The function subscribes to events published by Cloud Build. The events contain information on the status of the progress and completion of a build. The function copies a badge reflecting that status to a known URL, which can be hard-coded in a repository `README` (as seen above).
+
 ## Installation
 
 ### Upload Badges
@@ -43,9 +47,19 @@ Grant permissions to read and write to the bucket:
 gsutil iam ch serviceAccount:cloud-build-badge@${GOOGLE_CLOUD_PROJECT}.iam.gserviceaccount.com:legacyBucketReader,legacyObjectReader,legacyBucketWriter gs://${GOOGLE_CLOUD_PROJECT}-badges/
 ```
 
+# Customise Path
+
+You can customise the path in the bucket at which the badge gets published, using a template string. The default is:
+
+`builds/${repo}/branches/${branch}.svg`
+
+Where `${repo}` and `${branch}` refer to the name of the repository and branch that triggered the build. Only these two variables are available.
+
+Set the environment variable `TEMPLATE_PATH` accordingly when deploying the function in the next step.
+
 ## Deploy
 
-Deploy the function:
+Deploy the function. Note you can customise the path at which the badge gets produced, using a template string,
 
 ```bash
 gcloud functions deploy cloud-build-badge \
@@ -54,9 +68,21 @@ gcloud functions deploy cloud-build-badge \
     --entry-point build_badge \
     --service-account cloud-build-badge@${GOOGLE_CLOUD_PROJECT}.iam.gserviceaccount.com \
     --trigger-topic=cloud-builds \
-    --set-env-vars BADGES_BUCKET=${GOOGLE_CLOUD_PROJECT}-badges
+    --set-env-vars BADGES_BUCKET=${GOOGLE_CLOUD_PROJECT}-badges,TEMPLATE_PATH='builds/${repo}/branches/${branch}.svg'
 ```
 
+## Use
+
+Embed the badge in your README, replacing `${repo}` and `${branch}` with the name of your repository and the branch you want to show the latest status for:
+
+```
+![Cloud Build](https://storage.googleapis.com/${GOOGLE_CLOUD_PROJECT}-badges/builds/${repo}/branches/${branch})
+```
+
+If you've customised the path using `TEMPLATE_PATH`, ensure it is reflected in the URL above.
+
+Now trigger a Cloud Build build (e.g. by pushing a commit, or directly via the Google Cloud console). You should see the badge update to reflect the build status.
+
 ## Test
 
 There is a `make` task for running integration tests against the deployed function:

main.py

@@ -4,6 +4,7 @@
 import json
 import os
 import re
+from string import Template
 
 
 def copy_badge(bucket_name, obj, new_obj):
@@ -32,20 +33,25 @@ def build_badge(event, context):
     decoded = base64.b64decode(event['data']).decode('utf-8')
     data = json.loads(decoded)
 
+    bucket = os.environ['BADGES_BUCKET']
+
     try:
         repo = data['source']['repoSource']['repoName']
+        branch = data['source']['repoSource']['branchName']
 
         if repo.startswith('github_') or repo.startswith('bitbucket_'):
             # mirrored repo format: (github|bitbucket)_<owner>_<repo>
             repo = repo.split('_', 2)[-1]
     except KeyError:
         # github app
         repo = data['substitutions']['REPO_NAME']
+        branch = data['substitutions']['BRANCH_NAME']
     finally:
-        src = 'badges/{}.svg'.format(data['status'].lower())
-        dest = 'builds/{}.svg'.format(repo)
+        tmpl = os.environ.get('TEMPLATE_PATH',
+                'builds/${repo}/branches/${branch}.svg')
 
-        bucket = os.environ['BADGES_BUCKET']
+        src = 'badges/{}.svg'.format(data['status'].lower())
+        dest = Template(tmpl).substitute(repo=repo, branch=branch)
 
         copy_badge(bucket, src, dest)
 

tests/test_func.py

@@ -50,43 +50,60 @@ def github_app():
     return {
         "status": "SUCCESS",
         "substitutions": {
-              "REPO_NAME": "webapp"
+              "REPO_NAME": "webapp",
+              "BRANCH_NAME": "feature/fish"
         }
     }
 
 
 @pytest.fixture
-def env_vars(monkeypatch):
+def badges_bucket(monkeypatch):
     monkeypatch.setenv('BADGES_BUCKET', 'my-badges-bucket')
 
 
+@pytest.fixture
+def custom_template_path(monkeypatch):
+    monkeypatch.setenv('TEMPLATE_PATH', 'builds/${repo}-${branch}.svg')
+
+
 @pytest.fixture
 def patches(mocker):
     mocker.patch('main.copy_badge')
 
 
-def test_mirrored_repo(mirrored_repo, env_vars, patches):
+def test_mirrored_repo(mirrored_repo, badges_bucket, patches):
     main.build_badge(mirrored_repo, None)
 
     main.copy_badge.assert_called_once_with(
             'my-badges-bucket',
             'badges/success.svg',
-            'builds/webapp.svg')
+            'builds/webapp/branches/feature/fish.svg')
 
 
-def test_github_app(github_app, env_vars, patches):
+def test_github_app(github_app, badges_bucket, patches):
     main.build_badge(github_app, None)
 
     main.copy_badge.assert_called_once_with(
             'my-badges-bucket',
             'badges/success.svg',
-            'builds/webapp.svg')
+            'builds/webapp/branches/feature/fish.svg')
+
+
+def test_cloud_source_repo(cloud_source_repo, badges_bucket, patches):
+    main.build_badge(cloud_source_repo, None)
+
+    main.copy_badge.assert_called_once_with(
+            'my-badges-bucket',
+            'badges/working.svg',
+            'builds/webapp/branches/master.svg')
+
 
+def test_custom_template_path(cloud_source_repo, badges_bucket,
+        custom_template_path, patches):
 
-def test_cloud_source_repo(cloud_source_repo, env_vars, patches):
     main.build_badge(cloud_source_repo, None)
 
     main.copy_badge.assert_called_once_with(
             'my-badges-bucket',
             'badges/working.svg',
-            'builds/webapp.svg')
+            'builds/webapp-master.svg')