WIP: chore(coturn): Switch to letsencrypt certificate

Fixes #107

configuration/services/conduit/default.nix

@@ -59,11 +59,8 @@ in
     relay-ips = [ "116.202.158.55" ];
 
     # SSL config
-    #
-    # TODO(tlater): Switch to letsencrypt once google fix:
-    #  https://github.com/vector-im/element-android/issues/1533
-    pkey = config.sops.secrets."turn/ssl-key".path;
-    cert = config.sops.secrets."turn/ssl-cert".path;
+    pkey = "${config.security.acme.certs."tlater.net".directory}/key.pem";
+    cert = "${config.security.acme.certs."tlater.net".directory}/fullchain.pem";
 
     # Based on suggestions from
     # https://github.com/matrix-org/synapse/blob/develop/docs/turn-howto.md

configuration/services/metrics/exporters.nix

@@ -20,6 +20,16 @@ in
               timeout = "5s";
               http.preferred_ip_protocol = "ip4";
             };
+
+            turn_server = {
+              prober = "tcp";
+              timeout = "5s";
+              tcp = {
+                preferred_ip_protocol = "ip4";
+                source_ip_address = "116.202.158.55";
+                tls = true;
+              };
+            };
           };
         };
       };

configuration/services/metrics/victoriametrics.nix

@@ -40,6 +40,30 @@ in
         };
       };
 
+      blackbox_turn = {
+        targets = [ "turn.tlater.net:${toString config.services.coturn.tls-listening-port}" ];
+
+        extraSettings = {
+          metrics_path = "/probe";
+          params.module = [ "turn_server" ];
+
+          relabel_configs = [
+            {
+              source_labels = [ "__address__" ];
+              target_label = "__param_target";
+            }
+            {
+              source_labels = [ "__param_target" ];
+              target_label = "instance";
+            }
+            {
+              target_label = "__address__";
+              replacement = "${blackbox_host}:${toString blackbox_port}";
+            }
+          ];
+        };
+      };
+
       blackbox_exporter.targets = [ "${blackbox_host}:${toString blackbox_port}" ];
 
       coturn.targets = [ "127.0.0.1:9641" ];