Pull out redis validation into validator class

util/config/validators/buildlogredis.py

@@ -0,0 +1,16 @@
+import redis
+
+from util.config.validators import BaseValidator, ConfigValidationException
+
+class RedisValidator(BaseValidator):
+  name = "redis"
+
+  @classmethod
+  def validate(cls, config, user, user_password):
+    """ Validates connecting to redis. """
+    redis_config = config.get('BUILDLOGS_REDIS', {})
+    if not 'host' in  redis_config:
+      raise ConfigValidationException('Missing redis hostname')
+
+    client = redis.StrictRedis(socket_connect_timeout=5, **redis_config)
+    client.ping()

util/config/validators/test/test_buildlogredis.py

@@ -0,0 +1,24 @@
+import pytest
+import redis
+
+from mock import patch
+
+from mockredis import mock_strict_redis_client
+
+from util.config.validators import ConfigValidationException
+from util.config.validators.buildlogredis import RedisValidator
+
+@pytest.mark.parametrize('unvalidated_config,user,user_password,use_mock,expected', [
+  ({}, None, None, False, ConfigValidationException),
+  ({'BUILDLOGS_REDIS': {}}, None, None, False, ConfigValidationException),
+  ({'BUILDLOGS_REDIS': {'host': 'somehost'}}, None, None, False, redis.ConnectionError),
+  ({'BUILDLOGS_REDIS': {'host': 'localhost'}}, None, None, True, None),
+])
+def test_validate_redis(unvalidated_config, user, user_password, use_mock, expected):
+  with patch('redis.StrictRedis' if use_mock else 'redis.None', mock_strict_redis_client):
+    validator = RedisValidator()
+    if expected is not None:
+      with pytest.raises(expected):
+        validator.validate(unvalidated_config, user, user_password)
+    else:
+      validator.validate(unvalidated_config, user, user_password)