Unix domain socket

lib/statix.ex

@@ -331,9 +331,18 @@ defmodule Statix do
 
   @doc false
   def new_conn(module) do
-    {host, port, prefix} = load_config(module)
-    conn = Conn.new(host, port)
+    {conn, prefix} =
+      case load_config(module) do
+        {:inet, {host, port, prefix}} ->
+          conn = Conn.new(host, port)
+          {conn, prefix}
+
+        {:local, {socket_path, prefix}} ->
+          {Conn.new(:local, socket_path), prefix}
+      end
+
     header = IO.iodata_to_binary([conn.header | prefix])
+
     %{conn | header: header, sock: module}
   end
 
@@ -362,12 +371,16 @@ defmodule Statix do
 
     {prefix1, env1} = Keyword.pop_first(env1, :prefix)
     {prefix2, env2} = Keyword.pop_first(env2, :prefix)
+    prefix = build_prefix(prefix1, prefix2)
     env = Keyword.merge(env1, env2)
 
-    host = Keyword.get(env, :host, "127.0.0.1")
-    port = Keyword.get(env, :port, 8125)
-    prefix = build_prefix(prefix1, prefix2)
-    {host, port, prefix}
+    if env[:local] do
+      {:local, {env[:socket_path], prefix}}
+    else
+      host = Keyword.get(env, :host, "127.0.0.1")
+      port = Keyword.get(env, :port, 8125)
+      {:inet, {host, port, prefix}}
+    end
   end
 
   defp build_prefix(part1, part2) do

lib/statix/conn.ex

@@ -1,27 +1,37 @@
 defmodule Statix.Conn do
   @moduledoc false
 
-  defstruct [:sock, :header]
+  defstruct [:sock, :header, :type]
 
   alias Statix.Packet
 
   require Logger
 
+  def new(:local, path) do
+    header = Packet.header(:local, path)
+    %__MODULE__{header: header, type: :local}
+  end
+
   def new(host, port) when is_binary(host) do
     new(string_to_charlist(host), port)
   end
 
   def new(host, port) when is_list(host) or is_tuple(host) do
     {:ok, addr} = :inet.getaddr(host, :inet)
-    header = Packet.header(addr, port)
-    %__MODULE__{header: header}
+    header = Packet.header(:inet, addr, port)
+    %__MODULE__{header: header, type: :inet}
   end
 
-  def open(%__MODULE__{} = conn) do
+  def open(%__MODULE__{type: :inet} = conn) do
     {:ok, sock} = :gen_udp.open(0, active: false)
     %__MODULE__{conn | sock: sock}
   end
 
+  def open(%__MODULE__{type: :local} = conn) do
+    {:ok, sock} = :gen_udp.open(0, [:local, active: false])
+    %__MODULE__{conn | sock: sock}
+  end
+
   def transmit(%__MODULE__{header: header, sock: sock}, type, key, val, options)
       when is_binary(val) and is_list(options) do
     result =

lib/statix/packet.ex

@@ -5,8 +5,9 @@ defmodule Statix.Packet do
 
   otp_release = :erlang.system_info(:otp_release)
   @addr_family if(otp_release >= '19', do: [1], else: [])
+  @inet_local [5]
 
-  def header({n1, n2, n3, n4}, port) do
+  def header(:inet, {n1, n2, n3, n4}, port) do
     true = Code.ensure_loaded?(:gen_udp)
 
     anc_data_part =
@@ -27,6 +28,14 @@ defmodule Statix.Packet do
       ] ++ anc_data_part
   end
 
+  def header(:local, socket_path) do
+    @inet_local ++
+      [
+        byte_size(socket_path),
+        socket_path
+      ]
+  end
+
   def build(header, name, key, val, options) do
     [header, key, ?:, val, ?|, metric_type(name)]
     |> set_option(:sample_rate, options[:sample_rate])