Initial commit of netprep role

Change-Id: I2fb7fbaa37a70d29dee35d491c166088a3fae297
diff --git a/templates/nftables.conf.j2 b/templates/nftables.conf.j2
new file mode 100644
index 0000000..d24b47f
--- /dev/null
+++ b/templates/nftables.conf.j2
@@ -0,0 +1,32 @@
+#!/usr/sbin/nft -f
+{#
+SPDX-FileCopyrightText: © 2020 Open Networking Foundation <support@opennetworking.org>
+SPDX-License-Identifier: Apache-2.0
+#}
+
+flush ruleset
+
+# Primary rules
+table inet filter {
+	chain input {
+		type filter hook input priority 0;
+	}
+	chain forward {
+		type filter hook forward priority 0;
+	}
+	chain output {
+		type filter hook output priority 0;
+	}
+}
+
+# NAT
+table ip nat {
+	chain prerouting {
+		type nat hook prerouting priority -100;
+	}
+
+	chain postrouting {
+		type nat hook postrouting priority 100;
+		oifname "{{ netprep_nat_if }}" masquerade;
+	}
+}