[infra] Publish build badges on status page (#2513)

* [infra] Publish build badges on status page

* Address feedback from github PR

* Change success badge to 'fuzzing' and failing badge to 'build failing'

Author: ammaraskar

infra/gcb/badge_images/building.png

@@ -20,6 +20,7 @@
 
 STATUS_BUCKET = 'oss-fuzz-build-logs'
 SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
+BADGE_DIR = 'badges/'
 RETRY_COUNT = 3
 RETRY_WAIT = 5
 MAX_BUILD_RESULTS = 2000
@@ -173,6 +174,45 @@ def update_build_status(
   upload_status(successes, failures, status_filename)
 
 
+def update_build_badges(builds, projects, build_tag, coverage_tag):
+  for project in projects:
+    last_build = find_last_build(builds, project, build_tag)
+    last_coverage_build = find_last_build(builds, project, coverage_tag)
+    if not last_build or not last_coverage_build:
+      continue
+
+    badge = 'building'
+    if not is_build_successful(last_coverage_build):
+      badge = 'coverage_failing'
+    if not is_build_successful(last_build):
+      badge = 'failing'
+
+    print("[badge] {}: {}".format(project, badge))
+
+    storage_client = storage.Client()
+    status_bucket = storage_client.get_bucket(STATUS_BUCKET)
+
+    # Supported image types for badges
+    image_types = {
+        'svg': 'image/svg+xml',
+        'png': 'image/png'
+    }
+    for extension, mime_type in image_types.items():
+      badge_name = '{badge}.{extension}'.format(
+          badge=badge, extension=extension)
+      # Retrieve the image relative to this script's location
+      badge_file = os.path.join(
+          SCRIPT_DIR, 'badge_images', image_directory, badge_name)
+
+      # The uploaded blob name should look like `badges/project.png`
+      blob_name = '{badge_dir}{project_name}.{extension}'.format(
+          badge_dir=BADGE_DIR, project_name=project,
+          extension=extension)
+
+      badge_blob = status_bucket.blob(blob_name)
+      badge_blob.upload_from_filename(badge_file, content_type=mime_type)
+
+
 def main():
   if len(sys.argv) != 2:
     usage()
@@ -190,6 +230,10 @@ def main():
                       build_and_run_coverage.COVERAGE_BUILD_TAG,
                       status_filename='status-coverage.json')
 
+  update_build_badges(builds, projects,
+                      build_tag=build_project.FUZZING_BUILD_TAG,
+                      coverage_tag=build_and_run_coverage.COVERAGE_BUILD_TAG)
+
 
 if __name__ == '__main__':
   main()