Switch the license validator to use config_provider and have a test license

Fixes the broken tests currently which try (and fail) to read the license file

app.py

@@ -193,7 +193,7 @@ signer = Signer(app, config_provider)
 instance_keys = InstanceKeys(app)
 label_validator = LabelValidator(app)
 
-license_validator = LicenseValidator(os.path.join(OVERRIDE_CONFIG_DIRECTORY, LICENSE_FILENAME))
+license_validator = LicenseValidator(config_provider)
 license_validator.start()
 
 start_cloudwatch_sender(metric_queue, app)

test/test_api_security.py

@@ -4173,7 +4173,7 @@ class TestSuperUserLicense(ApiTestCase):
     self._run_test('GET', 403, 'reader', None)
 
   def test_get_devtable(self):
-    self._run_test('GET', 400, 'devtable', None)
+    self._run_test('GET', 200, 'devtable', None)
 
 
   def test_put_anonymous(self):

util/config/provider/testprovider.py

@@ -5,6 +5,18 @@ from util.config.provider.baseprovider import BaseProvider
 
 REAL_FILES = ['test/data/signing-private.gpg', 'test/data/signing-public.gpg']
 
+class TestLicense(object):
+  @property
+  def subscription(self):
+    return {}
+
+  @property
+  def is_expired(self):
+    return False
+
+  def validate(self, config):
+    pass
+
 class TestConfigProvider(BaseProvider):
   """ Implementation of the config provider for testing. Everything is kept in-memory instead on
       the real file system. """
@@ -58,6 +70,9 @@ class TestConfigProvider(BaseProvider):
   def requires_restart(self, app_config):
     return False
 
+  def get_license(self):
+    return TestLicense()
+
   def reset_for_test(self):
     self._config['SUPER_USERS'] = ['devtable']
     self.files = {}

util/license.py

@@ -190,8 +190,8 @@ class LicenseValidator(Thread):
   This thread is meant to be run before registry gunicorn workers fork and uses shared memory as a
   synchronization primitive.
   """
-  def __init__(self, license_path, *args, **kwargs):
-    self._license_path = license_path
+  def __init__(self, config_provider, *args, **kwargs):
+    self._config_provider = config_provider
 
     # multiprocessing.Value does not ensure consistent write-after-reads, but we don't need that.
     self._license_is_expired = multiprocessing.Value(c_bool, True)
@@ -205,8 +205,7 @@ class LicenseValidator(Thread):
 
   def _check_expiration(self):
     try:
-      with open(self._license_path) as f:
-        current_license = decode_license(f.read())
+      current_license = self._config_provider.get_license()
       is_expired = current_license.is_expired
       logger.debug('updating license expiration to %s', is_expired)
       self._license_is_expired.value = is_expired