Move config handling into a provider class to make testing much easier

util/config/configutil.py

@@ -7,35 +7,6 @@ def generate_secret_key():
   return  str(cryptogen.getrandbits(256))
 
 
-def import_yaml(config_obj, config_file):
-  with open(config_file) as f:
-    c = yaml.safe_load(f)
-    if not c:
-      logger.debug('Empty YAML config file')
-      return
-
-    if isinstance(c, str):
-      raise Exception('Invalid YAML config file: ' + str(c))
-
-    for key in c.iterkeys():
-      if key.isupper():
-        config_obj[key] = c[key]
-
-
-def export_yaml(config_obj, config_file):
-  with open(config_file, 'w') as f:
-    f.write(yaml.safe_dump(config_obj, encoding='utf-8', allow_unicode=True))
-
-
-def set_config_value(config_file, config_key, value):
-  """ Loads the configuration from the given YAML config file, sets the given key to
-      the given value, and then writes it back out to the given YAML config file. """
-  config_obj = {}
-  import_yaml(config_obj, config_file)
-  config_obj[config_key] = value
-  export_yaml(config_obj, config_file)
-
-
 def add_enterprise_config_defaults(config_obj, current_secret_key, hostname):
   """ Adds/Sets the config defaults for enterprise registry config. """
   # These have to be false.

util/config/provider.py

@@ -0,0 +1,139 @@
+import os
+import yaml
+import logging
+import json
+
+logger = logging.getLogger(__name__)
+
+def _import_yaml(config_obj, config_file):
+  with open(config_file) as f:
+    c = yaml.safe_load(f)
+    if not c:
+      logger.debug('Empty YAML config file')
+      return
+
+    if isinstance(c, str):
+      raise Exception('Invalid YAML config file: ' + str(c))
+
+    for key in c.iterkeys():
+      if key.isupper():
+        config_obj[key] = c[key]
+
+  return config_obj
+
+
+def _export_yaml(config_obj, config_file):
+  with open(config_file, 'w') as f:
+    f.write(yaml.safe_dump(config_obj, encoding='utf-8', allow_unicode=True))
+
+
+class BaseProvider(object):
+  """ A configuration provider helps to load, save, and handle config override in the application.
+  """
+
+  def update_app_config(self, app_config):
+    """ Updates the given application config object with the loaded override config. """
+    raise NotImplementedError
+
+  def get_yaml(self):
+    """ Returns the contents of the YAML config override file, or None if none. """
+    raise NotImplementedError
+
+  def save_yaml(self, config_object):
+    """ Updates the contents of the YAML config override file to those given. """
+    raise NotImplementedError
+
+  def yaml_exists(self):
+    """ Returns true if a YAML config override file exists in the config volume. """
+    raise NotImplementedError
+
+  def volume_exists(self):
+    """ Returns whether the config override volume exists. """
+    raise NotImplementedError
+
+  def volume_file_exists(self, filename):
+    """ Returns whether the file with the given name exists under the config override volume. """
+    raise NotImplementedError
+
+  def save_volume_file(self, filename, flask_file):
+    """ Saves the given flask file to the config override volume, with the given
+        filename.
+    """
+    raise NotImplementedError
+
+
+class FileConfigProvider(BaseProvider):
+  """ Implementation of the config provider that reads the data from the file system. """
+  def __init__(self, config_volume, yaml_filename, py_filename):
+    self.config_volume = config_volume
+    self.yaml_filename = yaml_filename
+    self.py_filename = py_filename
+
+    self.yaml_path = os.path.join(config_volume, yaml_filename)
+    self.py_path = os.path.join(config_volume, py_filename)
+
+  def update_app_config(self, app_config):
+    if os.path.exists(self.py_path):
+      logger.debug('Applying config file: %s', self.py_path)
+      app_config.from_pyfile(self.py_path)
+
+    if os.path.exists(self.yaml_path):
+      logger.debug('Applying config file: %s', self.yaml_path)
+      _import_yaml(app_config, self.yaml_path)
+
+  def get_yaml(self):
+    if not os.path.exists(self.yaml_path):
+      return None
+
+    config_obj = {}
+    _import_yaml(config_obj, self.yaml_path)
+    return config_obj
+
+  def save_yaml(self, config_obj):
+    _export_yaml(config_obj, self.yaml_path)
+
+  def yaml_exists(self):
+    return self.volume_file_exists(self.yaml_filename)
+
+  def volume_exists(self):
+    return os.path.exists(self.config_volume)
+
+  def volume_file_exists(self, filename):
+    return os.path.exists(os.path.join(self.config_volume, filename))
+
+  def save_volume_file(self, filename, flask_file):
+    flask_file.save(os.path.join(self.config_volume, filename))
+
+
+class TestConfigProvider(BaseProvider):
+  """ Implementation of the config provider for testing. Everything is kept in-memory instead on
+      the real file system. """
+  def __init__(self):
+    self.files = {}
+
+  def update_app_config(self, app_config):
+    pass
+
+  def get_yaml(self):
+    if not 'config.yaml' in self.files:
+      return None
+
+    return json.loads(self.files.get('config.yaml', '{}'))
+
+  def save_yaml(self, config_obj):
+    self.files['config.yaml'] = json.dumps(config_obj)
+
+  def yaml_exists(self):
+    return 'config.yaml' in self.files
+
+  def volume_exists(self):
+    return True
+
+  def volume_file_exists(self, filename):
+    return filename in self.files
+
+  def save_volume_file(self, filename, flask_file):
+    self.files[filename] = ''
+
+  def reset_for_test(self):
+    self.files = {}

util/config/validator.py

@@ -9,7 +9,7 @@ from flask import Flask
 from flask.ext.mail import Mail, Message
 from data.database import validate_database_url, User
 from storage import get_storage_driver
-from app import app, OVERRIDE_CONFIG_DIRECTORY
+from app import app, CONFIG_PROVIDER
 from auth.auth_context import get_authenticated_user
 from util.oauth import GoogleOAuthConfig, GithubOAuthConfig
 
@@ -138,7 +138,7 @@ def _validate_ssl(config):
     return
 
   for filename in SSL_FILENAMES:
-    if not os.path.exists(os.path.join(OVERRIDE_CONFIG_DIRECTORY, filename)):
+    if not CONFIG_PROVIDER.volume_file_exists(filename):
       raise Exception('Missing required SSL file: %s' % filename)