Fix empty authconfig detection

Signed-off-by: Joffrey F <joffrey@docker.com>

docker/api/build.py

@@ -286,10 +286,10 @@ class BuildApiMixin(object):
 
         # If we don't have any auth data so far, try reloading the config
         # file one more time in case anything showed up in there.
-        if not self._auth_configs:
+        if not self._auth_configs or self._auth_configs.is_empty:
             log.debug("No auth config in memory - loading from filesystem")
             self._auth_configs = auth.load_config(
-                credsore_env=self.credsore_env
+                credstore_env=self.credstore_env
             )
 
         # Send the full auth configuration (if any exists), since the build

docker/api/daemon.py

@@ -127,7 +127,7 @@ class DaemonApiMixin(object):
             self._auth_configs = auth.load_config(
                 dockercfg_path, credstore_env=self.credstore_env
             )
-        elif not self._auth_configs:
+        elif not self._auth_configs or self._auth_configs.is_empty:
             self._auth_configs = auth.load_config(
                 credstore_env=self.credstore_env
             )

docker/auth.py

@@ -39,7 +39,7 @@ def resolve_index_name(index_name):
 
 def get_config_header(client, registry):
     log.debug('Looking for auth config')
-    if not client._auth_configs:
+    if not client._auth_configs or client._auth_configs.is_empty:
         log.debug(
             "No auth config in memory - loading from filesystem"
         )
@@ -212,6 +212,12 @@ class AuthConfig(dict):
     def cred_helpers(self):
         return self.get('credHelpers', {})
 
+    @property
+    def is_empty(self):
+        return (
+            not self.auths and not self.creds_store and not self.cred_helpers
+        )
+
     def resolve_authconfig(self, registry=None):
         """
         Returns the authentication data from the given auth configuration for a