Add fail2ban

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/common/configs/system/sshd/default.nix

@@ -1,15 +1,27 @@
 { ... }:
 {
-  services.openssh = {
+  environment = {
+    enableAllTerminfo = true;
+    persistence."/persist"."/var/lib/fail2ban" = { };
+  };
+
+  services = {
+    openssh = {
       enable = true;
-    ports = [ 22 ];
-    openFirewall = true;
       settings = {
         PasswordAuthentication = false;
-      PermitRootLogin = "no";
         PrintMotd = false;
       };
     };
 
-  environment.enableAllTerminfo = true;
+    fail2ban = {
+      enable = true;
+      bantime = "24h";
+      bantime-increment = {
+        enable = true;
+        maxtime = "720h";
+        overalljails = true;
+      };
+    };
+  };
 }