Better organize the source file structure of the build manager and change it to choose a lifecycle manager based on the config

buildman/jobutil/buildjob.py

@@ -0,0 +1,60 @@
+from data import model
+
+import json
+
+class BuildJobLoadException(Exception):
+  """ Exception raised if a build job could not be instantiated for some reason. """
+  pass
+
+class BuildJob(object):
+  """ Represents a single in-progress build job. """
+  def __init__(self, job_item):
+    self._job_item = job_item
+
+    try:
+      self._job_details = json.loads(job_item.body)
+    except ValueError:
+      raise BuildJobLoadException(
+          'Could not parse build queue item config with ID %s' % self._job_details['build_uuid']
+      )
+
+    try:
+      self._repo_build = model.get_repository_build(self._job_details['namespace'],
+                                                    self._job_details['repository'],
+                                                    self._job_details['build_uuid'])
+    except model.InvalidRepositoryBuildException:
+      raise BuildJobLoadException(
+          'Could not load repository build with ID %s' % self._job_details['build_uuid'])
+
+    try:
+      self._build_config = json.loads(self._repo_build.job_config)
+    except ValueError:
+      raise BuildJobLoadException(
+          'Could not parse repository build job config with ID %s' % self._job_details['build_uuid']
+      )
+
+  def determine_cached_tag(self):
+    """ Returns the tag to pull to prime the cache or None if none. """
+    # TODO(jschorr): Change this to use the more complicated caching rules, once we have caching
+    # be a pull of things besides the constructed tags.
+    tags = self._build_config.get('docker_tags', ['latest'])
+    existing_tags = model.list_repository_tags(self._job_details['namespace'],
+                                               self._job_details['repository'])
+
+    cached_tags = set(tags) & set([tag.name for tag in existing_tags])
+    if cached_tags:
+      return list(cached_tags)[0]
+
+    return None
+
+  def job_item(self):
+    """ Returns the job's queue item. """
+    return self._job_item
+
+  def repo_build(self):
+    """ Returns the repository build DB row for the job. """
+    return self._repo_build
+
+  def build_config(self):
+    """ Returns the parsed repository build config for the job. """
+    return self._build_config