Merge pull request 'mqtt_broker' (#9) from mqtt_broker into master

Reviewed-on: https://git.rz.ens.wtf/HackENS/hackens-org-configurations/pulls/9

hosts/hackens-org/mosquitto.nix

@@ -0,0 +1,20 @@
+{ ... }:
+let
+  port = 1883;
+in
+{
+  services.mosquitto = {
+    enable = true;
+    logType = [ "all" ];
+    listeners = [
+      {
+        address = "0.0.0.0";
+        port = port;
+        settings = {
+          allow_anonymous = true;
+        };
+      }
+    ];
+  };
+  networking.firewall.allowedTCPPorts = [ port ];
+}