Support all schemas in the custom trigger

Fixes #266

buildtrigger/customhandler.py

@@ -1,7 +1,7 @@
 import logging
 import json
 
-from jsonschema import validate
+from jsonschema import validate, ValidationError
 from buildtrigger.triggerutil import (RepositoryReadException, TriggerActivationException,
                                       TriggerStartException, ValidationRequestException,
                                       InvalidPayloadException,
@@ -10,11 +10,60 @@ from buildtrigger.triggerutil import (RepositoryReadException, TriggerActivation
 
 from buildtrigger.basehandler import BuildTriggerHandler
 
+from buildtrigger.bitbuckethandler import (BITBUCKET_WEBHOOK_PAYLOAD_SCHEMA as bb_schema,
+                                           get_transformed_webhook_payload as bb_payload)
+
+from buildtrigger.githubhandler import (GITHUB_WEBHOOK_PAYLOAD_SCHEMA as gh_schema,
+                                        get_transformed_webhook_payload as gh_payload)
+
+from buildtrigger.bitbuckethandler import (BITBUCKET_WEBHOOK_PAYLOAD_SCHEMA as bb_schema,
+                                           get_transformed_webhook_payload as bb_payload)
+
+from buildtrigger.gitlabhandler import (GITLAB_WEBHOOK_PAYLOAD_SCHEMA as gl_schema,
+                                        get_transformed_webhook_payload as gl_payload)
+
 from util.security.ssh import generate_ssh_keypair
 
 
 logger = logging.getLogger(__name__)
 
+# Defines an ordered set of tuples of the schemas and associated transformation functions
+# for incoming webhook payloads.
+SCHEMA_AND_HANDLERS = [
+  (gh_schema, gh_payload),
+  (bb_schema, bb_payload),
+  (gl_schema, gl_payload),
+]
+
+
+def custom_trigger_payload(metadata, git_url):
+  # First try the customhandler schema. If it matches, nothing more to do.
+  custom_handler_validation_error = None
+  try:
+    validate(metadata, CustomBuildTrigger.payload_schema)
+  except ValidationError as vex:
+    custom_handler_validation_error = vex
+
+  # Otherwise, try the defined schemas, in order, until we find a match.
+  for schema, handler in SCHEMA_AND_HANDLERS:
+    try:
+      validate(metadata, schema)
+    except ValidationError:
+      continue
+
+    result = handler(metadata)
+    result['git_url'] = git_url
+    return result
+
+  # If we have reached this point and no other schemas validated, then raise the error for the
+  # custom schema.
+  if custom_handler_validation_error is not None:
+    raise InvalidPayloadException(custom_handler_validation_error.message)
+
+  metadata['git_url'] = git_url
+  return metadata
+
+
 class CustomBuildTrigger(BuildTriggerHandler):
   payload_schema = {
     'type': 'object',
@@ -101,13 +150,14 @@ class CustomBuildTrigger(BuildTriggerHandler):
   def is_active(self):
     return self.config.has_key('credentials')
 
-  def _metadata_from_payload(self, payload):
+  def _metadata_from_payload(self, payload, git_url):
+   # Parse the JSON payload.
     try:
       metadata = json.loads(payload)
-      validate(metadata, self.payload_schema)
-    except Exception as e:
-      raise InvalidPayloadException(e.message)
-    return metadata
+    except ValueError as vex:
+      raise InvalidPayloadException(vex.message)
+
+    return custom_trigger_payload(metadata, git_url)
 
   def handle_trigger_request(self, request):
     payload = request.data
@@ -116,9 +166,7 @@ class CustomBuildTrigger(BuildTriggerHandler):
 
     logger.debug('Payload %s', payload)
 
-    metadata = self._metadata_from_payload(payload)
-    metadata['git_url'] = self.config['build_source']
-
+    metadata = self._metadata_from_payload(payload, self.config['build_source'])
     prepared = self.prepare_build(metadata)
 
     # Check if we should skip this build.