ildkule/gatus/minecraft-checker: init

hosts/ildkule/services/monitoring/gatus/default.nix

@@ -3,6 +3,10 @@ let
   cfg = config.services.gatus;
 in
 {
+  imports = [
+    ./minecraft-checker.nix
+  ];
+
   services.gatus = {
     enable = true;
 
@@ -121,6 +125,12 @@ in
 
         (mkService "Gitea SSH" "ssh://git.pvv.ntnu.no:2222")
         (mkService "QoTD" "tcp://bekkalokk.pvv.ntnu.no:17")
+        (mkService "Minecraft" "http://localhost:25565" // {
+          conditions = [
+            "[STATUS] == 200"
+            "[BODY].ok == true"
+          ];
+        })
         (mkService "Email (SMTP)" "tcp://mail.pvv.ntnu.no:587")
         (mkService "Email (POP3)" "tcp://mail.pvv.ntnu.no:995")
         (mkService "Email (IMAP)" "tcp://mail.pvv.ntnu.no:993")

hosts/ildkule/services/monitoring/gatus/minecraft-checker.nix

@@ -0,0 +1,79 @@
+{ lib, pkgs, ... }:
+{
+  systemd.sockets."gatus-minecraft-checker" = {
+    wantedBy = [ "sockets.target" ];
+    listenStreams = [ "25565" ];
+    socketConfig = {
+      SocketMode = "0666";
+      Accept = false;
+    };
+  };
+
+  systemd.services."gatus-minecraft-checker" = {
+    serviceConfig = {
+      ExecStart = lib.getExe (pkgs.writers.writePython3Bin "gatus-minecraft-checker" {
+        libraries = with pkgs.python3Packages; [
+          # sdnotify
+          mcstatus
+        ];
+        flakeIgnore = [ "E501" "E704" ];
+      } ''
+        import socket
+        import json
+        from http.server import HTTPServer, BaseHTTPRequestHandler
+
+        from mcstatus import JavaServer
+
+
+        class Handler(BaseHTTPRequestHandler):
+            def do_GET(self):
+                try:
+                    mcserver = JavaServer.lookup("minecraft.pvv.ntnu.no")
+                    status = mcserver.status()
+
+                    body = {
+                        "ok": True,
+                        "players": status.players.online,
+                        "version": status.version.name,
+                        "latency": status.latency,
+                    }
+
+                    data = json.dumps(body).encode()
+
+                    self.send_response(200)
+                    self.send_header("Content-Type", "application/json")
+                    self.send_header("Content-Length", str(len(data)))
+                    self.end_headers()
+                    self.wfile.write(data)
+
+                except Exception as e:
+                    data = json.dumps({"ok": False, "error": str(e)}).encode()
+                    self.send_response(500)
+                    self.end_headers()
+                    self.wfile.write(data)
+
+
+        class NoBindHTTPServer(HTTPServer):
+            def server_bind(): pass
+            def server_activate(): pass
+
+
+        def main():
+            httpd = NoBindHTTPServer(
+                ("", 0),
+                Handler,
+                bind_and_activate=False,
+            )
+            httpd.socket = socket.fromfd(3, socket.AF_INET, socket.SOCK_STREAM)
+            httpd.serve_forever()
+
+
+        if __name__ == '__main__':
+            main()
+      '');
+
+      NoNewPrivileges = true;
+      PrivateTmp = true;
+    };
+  };
+}