Make s2i builder work on non-master refs

builder/app.py

@@ -120,7 +120,7 @@ class Builder(Application):
             bp = bp_class()
             if bp.detect(output_path):
                 self.log.info('Using %s builder', bp.name, extra=dict(phase='building'))
-                bp.build(output_path, self.output_image_spec)
+                bp.build(output_path, self.source_ref, self.output_image_spec)
                 break
         else:
             self.log.error('Could not figure out how to build this repository! Tell us?', extra=dict(phase='failed'))

builder/detectors.py

@@ -32,7 +32,7 @@ class BuildPack(LoggingConfigurable):
         """
         pass
 
-    def build(self, workdir, output_image_spec):
+    def build(self, workdir, ref, output_image_spec):
         """
         Run a command that will take workdir and produce an image ready to be pushed
         """
@@ -45,7 +45,7 @@ class DockerBuildPack(BuildPack):
     def detect(self, workdir):
         return os.path.exists(os.path.join(workdir, 'Dockerfile'))
 
-    def build(self, workdir, output_image_spec):
+    def build(self, workdir, ref, output_image_spec):
         client = docker.APIClient(base_url='unix://var/run/docker.sock', version='auto')
         for progress in client.build(
                 path=workdir,
@@ -77,11 +77,15 @@ class PythonBuildPack(BuildPack):
                 pass
             return True
 
-    def build(self, workdir, output_image_spec):
+    def build(self, workdir, ref, output_image_spec):
+        # Note: Ideally we'd just copy from workdir here, rather than clone and check out again
+        # However, setting just --copy and not specifying a ref seems to check out master for
+        # some reason. Investigate deeper FIXME
         cmd = [
             's2i',
             'build',
             '--exclude', '""',
+            '--ref', ref,
             workdir,
             self.runtime_builder_map[self.runtime],
             output_image_spec