add contrib

contrib/dhcpd.conf.erb

@@ -0,0 +1,35 @@
+option domain-name-servers <%= ', '.join(@dns_resolvers_ipv4) %>;
+option ntp-servers <%= ', '.join(@ntp_servers_ipv4) %>;
+
+# specify API server URL (RFC8910)
+option default-url "https://<%= @service_name %>/api/captive-portal";
+
+default-lease-time 600;
+max-lease-time 3600;
+
+authoritative;
+
+<% if @instances.length == 2 -%>
+failover peer "dhcp-peer" {
+    <% if @instance_index == 0 %>primary<% else %>secondary<% end %>;
+    address <%= @instances[@instance_index]['external_ipv4'] %>;
+    peer address <%= @instances[1-@instance_index]['external_ipv4'] %>;
+    max-response-delay 60;
+    max-unacked-updates 10;
+    load balance max seconds 3;
+<% if @instance_index == 0 -%>
+    split 128;
+    mclt 180;
+<%- end %>
+}
+<%- end %>
+
+subnet <%= @client_ipv4_net %> netmask <%= @client_netmask %> {
+    option routers <%= @client_ipv4_gateway %>;
+    pool {
+        range <%= @client_ipv4_dhcp_from %> <%= @client_ipv4_dhcp_to %>;
+<% if @instances.length == 2 -%>
+        failover peer "dhcp-peer";
+<%- end %>
+    }
+}