Redo the UI for the trigger setup dialog and add the ability for github triggers to be filtered using a regex on their branch name.

endpoints/trigger.py

@@ -3,6 +3,7 @@ import io
 import os.path
 import tarfile
 import base64
+import re
 
 from github import Github, UnknownObjectException, GithubException
 from tempfile import SpooledTemporaryFile
@@ -229,13 +230,35 @@ class GithubBuildTrigger(BuildTrigger):
 
     return repos_by_org
 
+  def matches_branch(self, branch_name, regex):
+    if not regex:
+      return False
+
+    m = regex.match(branch_name)
+    if not m:
+      return False
+
+    return len(m.group(0)) == len(branch_name)
+
   def list_build_subdirs(self, auth_token, config):
     gh_client = self._get_client(auth_token)
     source = config['build_source']
 
-    try:
+    try:      
       repo = gh_client.get_repo(source)
-      default_commit = repo.get_branch(repo.default_branch or 'master').commit
+
+      # Find the first matching branch.
+      branches = None
+      if 'branch_regex' in config:
+        try:
+          regex = re.compile(config['branch_regex'])
+          branches = [branch.name for branch in repo.get_branches()
+                                  if self.matches_branch(branch.name, regex)]
+        except:
+          pass
+
+      branches = branches or [repo.default_branch or 'master']
+      default_commit = repo.get_branch(branches[0]).commit
       commit_tree = repo.get_git_tree(default_commit.sha, recursive=True)
 
       return [os.path.dirname(elem.path) for elem in commit_tree.tree
@@ -330,7 +353,7 @@ class GithubBuildTrigger(BuildTrigger):
     payload = request.get_json()
     if not payload or payload.get('head_commit') is None:
       raise SkipRequestException()
-    
+
     if 'zen' in payload:
       raise ValidationRequestException()
 
@@ -339,6 +362,16 @@ class GithubBuildTrigger(BuildTrigger):
     commit_sha = payload['head_commit']['id']
     commit_message = payload['head_commit'].get('message', '')
 
+    if 'branch_regex' in config:
+      try:
+        regex = re.compile(config['branch_regex'])
+      except:
+        regex = re.compile('.*')
+
+      branch = ref.split('/')[-1]
+      if not self.matches_branch(branch, regex):
+        raise SkipRequestException()
+
     if should_skip_commit(commit_message):
       raise SkipRequestException()