Add support for reverse-proxying /_synapse/oidc

This broke in 63a49bb2dc7780e023b28.

Proxying the OpenID Connect endpoints is now possible,
but needs to be enabled explicitly now.

Supersedes #702 (Github Pull Request).

This patch builds up on the idea from that Pull Request,
but does things in a cleaner way.

docs/configuring-playbook-nginx.md

@@ -23,3 +23,12 @@ matrix_nginx_proxy_proxy_matrix_nginx_status_allowed_addresses:
 - 8.8.8.8
 - 1.1.1.1
 ```
+
+
+## Synapse + OpenID Connect for Single-Sign-On
+
+If you want to use OpenID Connect as an SSO provider (as per the [Synapse OpenID docs](https://github.com/matrix-org/synapse/blob/develop/docs/openid.md)), you need to use the following configuration (in your `vars.yml` file) to instruct nginx to forward `/_synapse/oidc` to Synapse:
+
+```yaml
+matrix_nginx_proxy_proxy_matrix_client_api_forwarded_location_synapse_oidc_api_enabled: true
+```

docs/configuring-playbook-synapse.md

@@ -21,3 +21,8 @@ Alternatively, **if there is no pre-defined variable** for a Synapse setting you
 ## Synapse Admin
 
 Certain Synapse administration tasks (managing users and rooms, etc.) can be performed via a web user-interace, if you install [Synapse Admin](configuring-playbook-synapse-admin.md).
+
+
+## Synapse + OpenID Connect for Single-Sign-On
+
+If you'd like to use OpenID Connect authentication with Synapse, you'll need some additional reverse-proxy configuration (see [our nginx reverse-proxy doc page](configuring-playbook-nginx.md#synapse-openid-connect-for-single-sign-on)).

roles/matrix-nginx-proxy/defaults/main.yml

@@ -150,10 +150,13 @@ matrix_nginx_proxy_proxy_matrix_client_api_addr_sans_container: "127.0.0.1:8008"
 matrix_nginx_proxy_proxy_matrix_client_api_client_max_body_size_mb: 50
 
 
-# Tells wheter `/_synapse/client` is forwarded to the Matrix Client API server.
+# Tells whether `/_synapse/client` is forwarded to the Matrix Client API server.
 matrix_nginx_proxy_proxy_matrix_client_api_forwarded_location_synapse_client_api_enabled: true
 
-# Tells wheter `/_synapse/admin` is forwarded to the Matrix Client API server.
+# Tells whether `/_synapse/oidc` is forwarded to the Matrix Client API server.
+matrix_nginx_proxy_proxy_matrix_client_api_forwarded_location_synapse_oidc_api_enabled: false
+
+# Tells whether `/_synapse/admin` is forwarded to the Matrix Client API server.
 # Following these recommendations (https://github.com/matrix-org/synapse/blob/master/docs/reverse_proxy.md), by default, we don't.
 matrix_nginx_proxy_proxy_matrix_client_api_forwarded_location_synapse_admin_api_enabled: false
 
@@ -166,6 +169,8 @@ matrix_nginx_proxy_proxy_matrix_client_api_forwarded_location_prefix_regexes: |
     +
     (['/_synapse/client'] if matrix_nginx_proxy_proxy_matrix_client_api_forwarded_location_synapse_client_api_enabled else [])
     +
+    (['/_synapse/oidc'] if matrix_nginx_proxy_proxy_matrix_client_api_forwarded_location_synapse_oidc_api_enabled else [])
+    +
     (['/_synapse/admin'] if matrix_nginx_proxy_proxy_matrix_client_api_forwarded_location_synapse_admin_api_enabled else [])
   }}