From b7ce5db782c0965aae064f7040177a702ca5e930 Mon Sep 17 00:00:00 2001
From: Edgar Geier <egeier@rhrk.uni-kl.de>
Date: Tue, 23 Jul 2019 12:38:09 +0200
Subject: [PATCH] Use fallback uid and gid if os.getuid() and os.getgid() are
 unavailable

---
 pre_commit/languages/docker.py | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/pre_commit/languages/docker.py b/pre_commit/languages/docker.py
index 59a53b4f..8eaf6f4e 100644
--- a/pre_commit/languages/docker.py
+++ b/pre_commit/languages/docker.py
@@ -14,6 +14,8 @@ from pre_commit.util import cmd_output
 
 ENVIRONMENT_DIR = 'docker'
 PRE_COMMIT_LABEL = 'PRE_COMMIT'
+FALLBACK_UID = 1000
+FALLBACK_GID = 1000
 get_default_version = helpers.basic_get_default_version
 healthy = helpers.basic_healthy
 
@@ -73,11 +75,25 @@ def install_environment(
         os.mkdir(directory)
 
 
+def getuid():
+    try:
+        return os.getuid()
+    except AttributeError:
+        return FALLBACK_UID
+
+
+def getgid():
+    try:
+        return os.getgid()
+    except AttributeError:
+        return FALLBACK_GID
+
+
 def docker_cmd():  # pragma: windows no cover
     return (
         'docker', 'run',
         '--rm',
-        '-u', '{}:{}'.format(os.getuid(), os.getgid()),
+        '-u', '{}:{}'.format(getuid(), getgid()),
         # 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.