matrix: enable synapse metrics for prometheus

matrix/entrypoint-synapse.sh

@@ -22,6 +22,7 @@ if [ ! -r "$HOMESERVER_YAML" ]; then
 #
 # added by hackerspace-zone setup scripts
 #
+enable_metrics: true
 suppress_key_server_warning: true
 web_client_location: https://${MATRIX_HOSTNAME}.${DOMAIN_NAME}
 public_baseurl: https://${MATRIX_HOSTNAME}.${DOMAIN_NAME}
@@ -38,6 +39,11 @@ oidc_providers:
         display_name_template: "{{ user.name }}"
 EOF
 
+# enable promemtheus metrics on a local-only port
+# since this is in docker, it won't be exposed to any outside connections
+	echo >&2 "**** Enabling prometheus metrics ****"
+	sed -i -e '/^listeners:/a\  - port: 9000\n    type: metrics\n' "$HOMESERVER_YAML"
+
 fi
 
 if ! grep -q '^  smtp_host:' && [ -n "$SMTP_SERVER" ]; then

prometheus/prometheus.yaml

@@ -19,3 +19,8 @@ scrape_configs:
       - targets: ['172.17.0.1:9100']
       # cadvisor system
       - targets: ['cadvisor:8080']
+  - job_name: "synapse"
+    scrape_interval: 15s
+    metrics_path: "/_synapse/metrics"
+    static_configs:
+      - targets: ["matrix-synapse:9000"]