Add license validation to the config validation check

Should prevent a customer from accidentally saving a config that violates their license

Fixes https://jira.coreos.com/browse/QS-97

util/config/validators/validate_license.py

@@ -0,0 +1,19 @@
+from app import config_provider
+from util.config.validators import BaseValidator, ConfigValidationException
+from util.license import LicenseDecodeError, EntitlementStatus
+
+class LicenseValidator(BaseValidator):
+  name = "license"
+
+  @classmethod
+  def validate(cls, config, user, user_password):
+    try:
+      decoded_license = config_provider.get_license()
+    except LicenseDecodeError as le:
+      raise ConfigValidationException('Could not decode license: %s' % le.message)
+
+    results = decoded_license.validate(config)
+    all_met = all(result.is_met() for result in results)
+    if not all_met:
+      reason = [result.description() for result in results if not result.is_met()]
+      raise ConfigValidationException('License does not match configuration: %s' % reason)