Add comment about python runtime to Dockerfile (GoogleCloudPlatform#662)

jeffmendoza · Jon Wayne Parrott · commit 540b21abaaa7 · 2016-11-16T14:32:47.000-08:00
Need to link to source of Docker image
diff --git a/endpoints/getting-started/Dockerfile.custom b/endpoints/getting-started/Dockerfile.custom
@@ -1,3 +1,7 @@
+# The Google App Engine python runtime is Debian Jessie with Python installed
+# and various os-level packages to allow installation of popular Python
+# libraries. The source is on github at:
+#   https://github.com/GoogleCloudPlatform/python-docker
 FROM gcr.io/google_appengine/python
 
 RUN apt-get update && \
