Add support for configuring CloudFront storage engine

Fixes https://jira.coreos.com/browse/QS-116

util/config/test/test_validator.py

@@ -0,0 +1,32 @@
+import pytest
+
+from util.config.validator import is_valid_config_upload_filename
+from util.config.validator import CONFIG_FILENAMES, CONFIG_FILE_SUFFIXES
+
+def test_valid_config_upload_filenames():
+  for filename in CONFIG_FILENAMES:
+    assert is_valid_config_upload_filename(filename)
+
+  for suffix in CONFIG_FILE_SUFFIXES:
+    assert is_valid_config_upload_filename('foo' + suffix)
+    assert not is_valid_config_upload_filename(suffix + 'foo')
+
+
+@pytest.mark.parametrize('filename, expect_valid', [
+  ('', False),
+  ('foo', False),
+  ('config.yaml', False),
+
+  ('ssl.cert', True),
+  ('ssl.key', True),
+
+  ('ssl.crt', False),
+
+  ('foobar-cloudfront-signing-key.pem', True),
+  ('foobaz-cloudfront-signing-key.pem', True),
+  ('barbaz-cloudfront-signing-key.pem', True),
+
+  ('barbaz-cloudfront-signing-key.pem.bak', False),
+])
+def test_is_valid_config_upload_filename(filename, expect_valid):
+  assert is_valid_config_upload_filename(filename) == expect_valid

util/config/validator.py

@@ -38,6 +38,7 @@ ACI_CERT_FILENAMES = ['signing-public.gpg', 'signing-private.gpg']
 LDAP_FILENAMES = [LDAP_CERT_FILENAME]
 CONFIG_FILENAMES = (SSL_FILENAMES + DB_SSL_FILENAMES + JWT_FILENAMES + ACI_CERT_FILENAMES +
                     LDAP_FILENAMES)
+CONFIG_FILE_SUFFIXES = ['-cloudfront-signing-key.pem']
 EXTRA_CA_DIRECTORY = 'extra_ca_certs'
 
 VALIDATORS = {
@@ -83,3 +84,13 @@ def validate_service_for_config(service, config, password=None):
       'status': False,
       'reason': str(ex)
     }
+
+
+def is_valid_config_upload_filename(filename):
+  """ Returns true if and only if the given filename is one which is supported for upload
+      from the configuration UI tool.
+  """
+  if filename in CONFIG_FILENAMES:
+    return True
+
+  return any([filename.endswith(suffix) for suffix in CONFIG_FILE_SUFFIXES])