Call out the need for an X-Forwarded-Proto in the upgrade notes (#9501)

1 files changed, 20 insertions, 0 deletions

diff --git a/UPGRADE.rst b/UPGRADE.rst

index 6f628a6947..e852b806c2 100644
--- a/UPGRADE.rst
+++ b/UPGRADE.rst
@@ -85,6 +85,26 @@ for example:
      wget https://packages.matrix.org/debian/pool/main/m/matrix-synapse-py3/matrix-synapse-py3_1.3.0+stretch1_amd64.deb
      dpkg -i matrix-synapse-py3_1.3.0+stretch1_amd64.deb
 
+Upgrading to v1.29.0
+====================
+
+Requirement for X-Forwarded-Proto header
+----------------------------------------
+
+When using Synapse with a reverse proxy (in particular, when using the
+`x_forwarded` option on an HTTP listener), Synapse now expects to receive an
+`X-Forwarded-Proto` header on incoming HTTP requests. If it is not set, Synapse
+will log a warning on each received request.
+
+To avoid the warning, administrators using a reverse proxy should ensure that
+the reverse proxy sets `X-Forwarded-Proto` header to `https` or `http` to
+indicate the protocol used by the client. See the [reverse proxy
+documentation](docs/reverse_proxy.md), where the example configurations have
+been updated to show how to set this header.
+
+(Users of `Caddy <https://caddyserver.com/>`_ are unaffected, since we believe it
+sets `X-Forwarded-Proto` by default.)
+
 Upgrading to v1.27.0
 ====================