1 files changed, 30 insertions, 0 deletions
diff --git a/system/services/fail2ban/default.nix b/system/services/fail2ban/default.nix
new file mode 100644
index 0000000..5aee097
--- /dev/null
+++ b/system/services/fail2ban/default.nix
@@ -0,0 +1,30 @@
+# vim: ts=2
+{...}: {
+  services.fail2ban = {
+    enable = true;
+    maxretry = 2; # ban after 2 failures
+    daemonConfig = ''
+      [Definition]
+      logtarget = SYSLOG
+      socket    = /run/fail2ban/fail2ban.sock
+      pidfile   = /run/fail2ban/fail2ban.pid
+      dbfile    = /srv/fail2ban/fail2ban.sqlite3
+    '';
+    bantime-increment = {
+      enable = true;
+      rndtime = "8m";
+      overalljails = true;
+      multipliers = "2 4 16 128 256";
+      maxtime = "72h";
+    };
+    jails = {
+      dovecot = ''
+        # block IPs which failed to log-in
+        # aggressive mode add blocking for aborted connections
+        enabled = true
+        filter = dovecot[mode=aggressive]
+        maxretry = 2
+      '';
+    };
+  };
+}