Merge pull request #1094 from geieredgar/windows-docker-fix

Fix docker based hooks failing on Windows

pre_commit/languages/docker.py

@@ -73,11 +73,18 @@ def install_environment(
         os.mkdir(directory)
 
 
+def get_docker_user():  # pragma: windows no cover
+    try:
+        return '{}:{}'.format(os.getuid(), os.getgid())
+    except AttributeError:
+        return '1000:1000'
+
+
 def docker_cmd():  # pragma: windows no cover
     return (
         'docker', 'run',
         '--rm',
-        '-u', '{}:{}'.format(os.getuid(), os.getgid()),
+        '-u', get_docker_user(),
         # https://docs.docker.com/engine/reference/commandline/run/#mount-volumes-from-container-volumes-from
         # The `Z` option tells Docker to label the content with a private
         # unshared label. Only the current container can use a private volume.

tests/languages/docker_test.py

@@ -13,3 +13,14 @@ def test_docker_is_running_process_error():
         side_effect=CalledProcessError(*(None,) * 4),
     ):
         assert docker.docker_is_running() is False
+
+
+def test_docker_fallback_user():
+    def invalid_attribute():
+        raise AttributeError
+    with mock.patch.multiple(
+        'os', create=True,
+        getuid=invalid_attribute,
+        getgid=invalid_attribute,
+    ):
+        assert docker.get_docker_user() == '1000:1000'