badvpn/ncd/examples/make_dhcp_config.ncd

process main {
    call("make_dhcp_config", {"192.168.1.1", "24", "192.168.1.100", "192.168.1.199", {"192.168.1.1"}, {"192.168.1.1", "4.4.4.4"}, "dhcpd.conf.template", "dhcpd.conf"}) config;
    exit("0");
}

template make_dhcp_config {
    alias("_arg0") addr;
    alias("_arg1") prefix;
    alias("_arg2") range_start;
    alias("_arg3") range_end;
    alias("_arg4") routers;
    alias("_arg5") dns_servers;
    alias("_arg6") template_file;
    alias("_arg7") output_file;

    ipv4_net_from_addr_and_prefix(addr, prefix) network;
    ipv4_prefix_to_mask(prefix) netmask;
    implode(", ", routers) routers_str;
    implode(", ", dns_servers) dns_servers_str;

    var({"<LOCAL_ADDRESS>", "<NETWORK>", "<NETMASK>", "<RANGE_START>", "<RANGE_END>", "<ROUTERS>", "<DNS_SERVERS>"}) regex;
    var({addr, network, netmask, range_start, range_end, routers_str, dns_servers_str}) replace;

    file_read(template_file) template_data;
    regex_replace(template_data, regex, replace) replaced_data;
    file_write(output_file, replaced_data);
}