Make tunnel timeout for nova_serialconsole_proxy configurable

Currently, the serial consoles as accessed through Horizon,
timeout after the haproxy_client_timeout (default: 1m) of
inactivity. This change allows you to set a larger timeout.

Change-Id: I2a9923cb69d5db976395146685aded83922c4120
Closes-Bug: #1800643

ansible/roles/nova/defaults/main.yml

@@ -183,11 +183,15 @@ nova_services:
         mode: "http"
         external: false
         port: "{{ nova_serialproxy_port }}"
+        backend_http_extra:
+          - "timeout tunnel {{ haproxy_nova_serialconsole_proxy_tunnel_timeout }}"
       nova_serialconsole_proxy_external:
         enabled: "{{ enable_nova|bool and enable_nova_serialconsole_proxy|bool }}"
         mode: "http"
         external: true
         port: "{{ nova_serialproxy_port }}"
+        backend_http_extra:
+          - "timeout tunnel {{ haproxy_nova_serialconsole_proxy_tunnel_timeout }}"
   nova-conductor:
     container_name: "nova_conductor"
     group: "nova-conductor"
@@ -342,6 +346,11 @@ nova_conductor_dimensions: "{{ default_container_dimensions }}"
 nova_compute_dimensions: "{{ default_container_dimensions }}"
 nova_compute_ironic_dimensions: "{{ default_container_dimensions }}"
 
+####################
+# HAProxy
+####################
+haproxy_nova_serialconsole_proxy_tunnel_timeout: "10m"
+
 ####################
 # OpenStack
 ####################

releasenotes/notes/add-option-to-configure-nova-serial-console-timeout-7cfc764a0c19eb01.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    Added an option, haproxy_nova_serialconsole_proxy_tunnel_timeout,
+    to configure the nova_serialconsole_proxy tunnel timeout. This default
+    is to keep the websocket connection alive for 10 minutes.