nixos/prosody: Integrate go-sendxmpp into test

nixos/tests/xmpp/prosody.nix

@@ -3,7 +3,7 @@ let
     pkgs:
     pkgs.runCommand "selfSignedCerts" { buildInputs = [ pkgs.openssl ]; } ''
       openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -nodes -days 365 \
-        -subj '/C=GB/CN=example.com' -addext "subjectAltName = DNS:example.com,DNS:uploads.example.com,DNS:conference.example.com"
+        -subj '/C=GB/CN=example.com/CN=uploads.example.com/CN=conference.example.com' -addext "subjectAltName = DNS:example.com,DNS:uploads.example.com,DNS:conference.example.com"
       mkdir -p $out
       cp key.pem cert.pem $out
     '';
@@ -32,7 +32,18 @@ in
 import ../make-test-python.nix {
   name = "prosody";
   nodes = {
-    client =
+    client-a =
+      { nodes, pkgs, ... }:
+      {
+        security.pki.certificateFiles = [ "${cert pkgs}/cert.pem" ];
+        networking.extraHosts = ''
+          ${nodes.server.networking.primaryIPAddress} example.com
+        '';
+
+        imports = [ ./go-sendxmpp-listen.nix ];
+      };
+
+    client-b =
       {
         nodes,
         pkgs,
@@ -93,7 +104,18 @@ import ../make-test-python.nix {
     server.succeed('prosodyctl status | grep "Prosody is running"')
 
     server.succeed("create-prosody-users")
-    client.succeed("send-message")
+
+    for machine in client_a, client_b:
+      machine.systemctl("start network-online.target")
+      machine.wait_for_unit("network-online.target")
+
+    client_a.wait_for_unit("go-sendxmpp-listen")
+    client_b.succeed("send-message")
+
+    client_a.wait_until_succeeds(
+      "journalctl -o cat -u go-sendxmpp-listen.service | grep 'cthon98@example.com: Hello, this is dog.'"
+    )
+
     server.succeed("delete-prosody-users")
   '';
 }