Adds troubleshooting note for Kubernetes about needing to set the port again

diff --git a/docs/troubleshooting.rst b/docs/troubleshooting.rst
index 6d94d710099b0bf7d75e36ae390fe41e1fdac4a8..8ab9b322402a015f621aa953235b884005890fd7 100644 (file)
--- a/docs/troubleshooting.rst
+++ b/docs/troubleshooting.rst
@@ -317,3 +317,12 @@ Uploading or consuming multiple files at once results in many workers attempting
 Consider changing to the PostgreSQL database if you will be processing many documents at once often.  Otherwise,
 try tweaking the ``PAPERLESS_DB_TIMEOUT`` setting to allow more time for the database to unlock.  This may have
 minor performance implications.
+
+
+gunicorn fails to start with "is not a valid port number"
+#########################################################
+
+You are likely running using Kubernetes, which automatically creates an environment variable named `${serviceName}_PORT`.
+This is the same environment variable which is used by Paperless to optionally change the port gunicorn listens on.
+
+To fix this, set `PAPERLESS_PORT` again to your desired port, or the default of 8000.