DNS library for Elixir.
Currently, the package provides:
- Elixir structs to interface with
:inet_dnsmodule DNS.Serverbehavior- DNS client
Note: the :inet_dns module is considered internal to Erlang and subject to change. If this happened this library will be updated to accommodate for that, but for now :inet_dns is simple and worked for me.
Make sure you have the Erlang/OTP source files installed, otherwise the compilation will fail with an {:error, :enoent} message. On Ubuntu, this can be done using apt-get install erlang-src.
Add :dns to your list of dependencies in mix.exs:
def deps do [ {:dns, "~> 2.4.0"} ] endiex> DNS.resolve("google.com") {:ok, [{216, 58, 221, 110}]} iex> DNS.resolve("notfound.domain") {:error, :not_found} iex> DNS.query("google.com") %DNS.Record{anlist: [%DNS.Resource{bm: [], class: :in, cnt: 0, data: {216, 58, 221, 110}, domain: 'google.com', func: false, tm: :undefined, ttl: 129, type: :a}], arlist: [], header: %DNS.Header{aa: false, id: 0, opcode: :query, pr: false, qr: true, ra: true, rcode: 0, rd: false, tc: false}, nslist: [], qdlist: [%DNS.Query{class: :in, domain: 'google.com', type: :a}]} iex> DNS.resolve("google.com", :a, {"8.8.8.8", 53}) ...defmodule ServerExample do @moduledoc """ Example implementing DNS.Server behaviour """ @behaviour DNS.Server use DNS.Server def handle(record, _cl) do Logger.info(fn -> "#{inspect(record)}" end) query = hd(record.qdlist) result = case query.type do :a -> {127, 0, 0, 1} :cname -> 'your.domain.com' :txt -> ['your txt value'] _ -> nil end resource = %DNS.Resource{ domain: query.domain, class: query.class, type: query.type, ttl: 0, data: result } %{record | anlist: [resource], header: %{record.header | qr: true}} end endTo run the example server in iex:
iex> c "example/test_server.ex" [ServerExample] iex> {:ok, server_pid} = ServerExample.start_link 8000 Server listening at 8000 {:ok, #PID<0.180.0>} iex> Process.exit(server_pid, :normal) Copyright (c) 2016-2022 Tung Dao and contributors.
This library is released under the BSD 3-Clause "New" or "Revised" License. See the LICENSE.md file for further details.
