From 996a77af790f25a271a4c2760b9ca47da6503121 Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Wed, 18 Apr 2018 16:28:49 +0200
Subject: [PATCH 01/17] Send milliseconds in timestamp to Logstash. Remove
 dependency on `Timex` and `exjsx`.

---
 README.md                             |   8 +-
 lib/logger_logstash_backend.ex        | 107 +++++++++++++++-----------
 mix.exs                               |  23 +++---
 mix.lock                              |   7 +-
 test/logger_logstash_backend_test.exs |  62 ++++++++-------
 5 files changed, 122 insertions(+), 85 deletions(-)

diff --git a/README.md b/README.md
index ec55fd8..8b71913 100644
--- a/README.md
+++ b/README.md
@@ -16,6 +16,8 @@ that will send logs to the [Logstash UDP input](https://www.elastic.co/guide/en/
  be merged with the metadata sent in every log message.
  * **level**: Atom. Minimum level for this backend.
  * **type**: String.t. Type of logs. Useful to filter in logstash.
+ * **timezone**: String.t. Server timezone. Used to convert from naive timestamp. Default `"Etc/UTC"`.
+ * **json_encoder**: Atom. Module to be used for JSON encoding. Default `Jason`.
 
 ## Sample Logstash config
 ```
@@ -51,7 +53,7 @@ Add logger and tzdata as applications:
 
 ```elixir
 def application do
-  [applications: [:logger, :timex]]
+  [applications: [:logger]]
 end
 ```
 
@@ -81,5 +83,7 @@ config :logger, :error_log,
   type: "my_type_of_app_or_node",
   metadata: [
     extra_fields: "go here"
-  ]
+  ],
+  timezone: "Etc/UTC",
+  json_encoder: Jason
 ```
diff --git a/lib/logger_logstash_backend.ex b/lib/logger_logstash_backend.ex
index 905adaa..ca357f5 100644
--- a/lib/logger_logstash_backend.ex
+++ b/lib/logger_logstash_backend.ex
@@ -15,7 +15,6 @@
 ################################################################################
 defmodule LoggerLogstashBackend do
   @behaviour :gen_event
-  use Timex
 
   def init({__MODULE__, name}) do
     {:ok, configure(name, [])}
@@ -34,11 +33,13 @@ defmodule LoggerLogstashBackend do
   end
 
   def handle_event(
-    {level, _gl, {Logger, msg, ts, md}}, %{level: min_level} = state
-  ) do
+        {level, _gl, {Logger, msg, ts, md}},
+        %{level: min_level} = state
+      ) do
     if is_nil(min_level) or Logger.compare_levels(level, min_level) != :lt do
-      log_event level, msg, ts, md, state
+      log_event(level, msg, ts, md, state)
     end
+
     {:ok, state}
   end
 
@@ -50,46 +51,62 @@ defmodule LoggerLogstashBackend do
     :ok
   end
 
-  defp log_event(
-    level, msg, ts, md, %{
-      host: host,
-      port: port,
-      type: type,
-      metadata: metadata,
-      socket: socket
-    }
-  ) do
-    fields = md
-             |> Keyword.merge(metadata)
-             |> Enum.into(%{})
-             |> Map.put(:level, to_string(level))
-             |> inspect_pids
-
-    {{year, month, day}, {hour, minute, second, milliseconds}} = ts
-    {:ok, ts} = NaiveDateTime.new(
-      year, month, day, hour, minute, second, (milliseconds * 1000)
-    )
-    ts = Timex.to_datetime ts, Timezone.local
-    {:ok, json} = JSX.encode %{
-      type: type,
-      "@timestamp": Timex.format!(ts, "{ISO:Extended}"),
-      message: to_string(msg),
-      fields: fields
-    }
-    :gen_udp.send socket, host, port, to_charlist(json)
+  defp log_event(level, msg, ts, md, %{
+         host: host,
+         port: port,
+         type: type,
+         metadata: metadata,
+         socket: socket,
+         timezone: timezone,
+         json_encoder: json_encoder
+       }) do
+    fields =
+      md
+      |> Keyword.merge(metadata)
+      |> Enum.into(%{})
+      |> Map.put(:level, to_string(level))
+      |> inspect_pids
+
+    {{year, month, day}, {hour, minute, second, microseconds}} = ts
+
+    {:ok, ts} =
+      NaiveDateTime.new(
+        year,
+        month,
+        day,
+        hour,
+        minute,
+        second,
+        microseconds * 1000
+      )
+
+    {:ok, datetime} = DateTime.from_naive(ts, timezone)
+
+    {:ok, json} =
+      json_encoder.encode(%{
+        type: type,
+        "@timestamp": DateTime.to_iso8601(datetime),
+        message: to_string(msg),
+        fields: fields
+      })
+
+    :gen_udp.send(socket, host, port, to_charlist(json))
   end
 
   defp configure(name, opts) do
-    env = Application.get_env :logger, name, []
-    opts = Keyword.merge env, opts
-    Application.put_env :logger, name, opts
-
-    level = Keyword.get opts, :level, :debug
-    metadata = Keyword.get opts, :metadata, []
-    type = Keyword.get opts, :type, "elixir"
-    host = Keyword.get opts, :host
-    port = Keyword.get opts, :port
-    {:ok, socket} = :gen_udp.open 0
+    env = Application.get_env(:logger, name, [])
+    opts = Keyword.merge(env, opts)
+    Application.put_env(:logger, name, opts)
+
+    level = Keyword.get(opts, :level, :debug)
+    metadata = Keyword.get(opts, :metadata, [])
+    type = Keyword.get(opts, :type, "elixir")
+    host = Keyword.get(opts, :host)
+    port = Keyword.get(opts, :port)
+    timezone = Keyword.get(opts, :timezone, "Etc/UTC")
+    json_encoder = Keyword.get(opts, :json_encoder, Jason)
+    {:ok, socket} = :gen_udp.open(0)
+
     %{
       name: name,
       host: to_charlist(host),
@@ -97,7 +114,9 @@ defmodule LoggerLogstashBackend do
       level: level,
       socket: socket,
       type: type,
-      metadata: metadata
+      metadata: metadata,
+      timezone: timezone,
+      json_encoder: json_encoder
     }
   end
 
@@ -107,8 +126,8 @@ defmodule LoggerLogstashBackend do
 
   # inspects the field values only if they are pids
   defp inspect_pids(fields) when is_map(fields) do
-    Enum.into fields, %{}, fn {key, value} ->
+    Enum.into(fields, %{}, fn {key, value} ->
       {key, inspect_pid(value)}
-    end
+    end)
   end
 end
diff --git a/mix.exs b/mix.exs
index 97ebf83..a5bd852 100644
--- a/mix.exs
+++ b/mix.exs
@@ -2,26 +2,27 @@ defmodule LoggerLogstashBackend.Mixfile do
   use Mix.Project
 
   def project do
-    [app: :logger_logstash_backend,
-     name: "logger_logstash_backend",
-     source_url: "https://github.com/marcelog/logger_logstash_backend",
-     version: "5.0.0",
-     elixir: "~> 1.3",
-     description: description(),
-     package: package(),
-     deps: deps()]
+    [
+      app: :logger_logstash_backend,
+      name: "logger_logstash_backend",
+      source_url: "https://github.com/marcelog/logger_logstash_backend",
+      version: "5.0.0",
+      elixir: "~> 1.3",
+      description: description(),
+      package: package(),
+      deps: deps()
+    ]
   end
 
   def application do
-    [applications: [:logger, :timex, :exjsx]]
+    [applications: [:logger]]
   end
 
   defp deps do
     [
       {:earmark, "~> 1.0.3", only: :dev},
       {:ex_doc, "~> 0.14.5", only: :dev},
-      {:exjsx, "~> 3.2.1"},
-      {:timex, "~> 3.1.8"}
+      {:jason, "~> 1.0", only: [:dev, :test]}
     ]
   end
 
diff --git a/mix.lock b/mix.lock
index 7183b40..0794cbc 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,4 +1,5 @@
-%{"certifi": {:hex, :certifi, "0.7.0", "861a57f3808f7eb0c2d1802afeaae0fa5de813b0df0979153cbafcd853ababaf", [:rebar3], []},
+%{
+  "certifi": {:hex, :certifi, "0.7.0", "861a57f3808f7eb0c2d1802afeaae0fa5de813b0df0979153cbafcd853ababaf", [:rebar3], []},
   "combine": {:hex, :combine, "0.9.6", "8d1034a127d4cbf6924c8a5010d3534d958085575fa4d9b878f200d79ac78335", [:mix], []},
   "earmark": {:hex, :earmark, "1.0.3", "89bdbaf2aca8bbb5c97d8b3b55c5dd0cff517ecc78d417e87f1d0982e514557b", [:mix], []},
   "ex_doc": {:hex, :ex_doc, "0.14.5", "c0433c8117e948404d93ca69411dd575ec6be39b47802e81ca8d91017a0cf83c", [:mix], [{:earmark, "~> 1.0", [hex: :earmark, optional: false]}]},
@@ -6,9 +7,11 @@
   "gettext": {:hex, :gettext, "0.13.0", "daafbddc5cda12738bb93b01d84105fe75b916a302f1c50ab9fb066b95ec9db4", [:mix], []},
   "hackney": {:hex, :hackney, "1.6.5", "8c025ee397ac94a184b0743c73b33b96465e85f90a02e210e86df6cbafaa5065", [:rebar3], [{:certifi, "0.7.0", [hex: :certifi, optional: false]}, {:idna, "1.2.0", [hex: :idna, optional: false]}, {:metrics, "1.0.1", [hex: :metrics, optional: false]}, {:mimerl, "1.0.2", [hex: :mimerl, optional: false]}, {:ssl_verify_fun, "1.1.1", [hex: :ssl_verify_fun, optional: false]}]},
   "idna": {:hex, :idna, "1.2.0", "ac62ee99da068f43c50dc69acf700e03a62a348360126260e87f2b54eced86b2", [:rebar3], []},
+  "jason": {:hex, :jason, "1.0.0", "0f7cfa9bdb23fed721ec05419bcee2b2c21a77e926bce0deda029b5adc716fe2", [:mix], [{:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm"},
   "jsx": {:hex, :jsx, "2.8.1", "1453b4eb3615acb3e2cd0a105d27e6761e2ed2e501ac0b390f5bbec497669846", [:mix, :rebar3], []},
   "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [:rebar3], []},
   "mimerl": {:hex, :mimerl, "1.0.2", "993f9b0e084083405ed8252b99460c4f0563e41729ab42d9074fd5e52439be88", [:rebar3], []},
   "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.1", "28a4d65b7f59893bc2c7de786dec1e1555bd742d336043fe644ae956c3497fbe", [:make, :rebar], []},
   "timex": {:hex, :timex, "3.1.8", "a32f636c4260dd7515a3767be3d3a163dc09d15f0e9e689254b7bab152b29209", [:mix], [{:combine, "~> 0.7", [hex: :combine, optional: false]}, {:gettext, "~> 0.10", [hex: :gettext, optional: false]}, {:tzdata, "~> 0.1.8 or ~> 0.5", [hex: :tzdata, optional: false]}]},
-  "tzdata": {:hex, :tzdata, "0.5.10", "087e8dfe8c0283473115ad8ca6974b898ecb55ca5c725427a142a79593391e90", [:mix], [{:hackney, "~> 1.0", [hex: :hackney, optional: false]}]}}
+  "tzdata": {:hex, :tzdata, "0.5.10", "087e8dfe8c0283473115ad8ca6974b898ecb55ca5c725427a142a79593391e90", [:mix], [{:hackney, "~> 1.0", [hex: :hackney, optional: false]}]},
+}
diff --git a/test/logger_logstash_backend_test.exs b/test/logger_logstash_backend_test.exs
index 20ea190..d1335b1 100644
--- a/test/logger_logstash_backend_test.exs
+++ b/test/logger_logstash_backend_test.exs
@@ -16,13 +16,13 @@
 defmodule LoggerLogstashBackendTest do
   use ExUnit.Case, async: false
   require Logger
-  use Timex
 
   @backend {LoggerLogstashBackend, :test}
-  Logger.add_backend @backend
+  Logger.add_backend(@backend)
 
   setup do
-    Logger.configure_backend @backend, [
+    Logger.configure_backend(
+      @backend,
       host: "127.0.0.1",
       port: 10001,
       level: :info,
@@ -30,69 +30,79 @@ defmodule LoggerLogstashBackendTest do
       metadata: [
         some_metadata: "go here"
       ]
-    ]
-    {:ok, socket} = :gen_udp.open 10001, [:binary, {:active, true}]
-    on_exit fn ->
-      :ok = :gen_udp.close socket
-    end
+    )
+
+    {:ok, socket} = :gen_udp.open(10001, [:binary, {:active, true}])
+
+    on_exit(fn ->
+      :ok = :gen_udp.close(socket)
+    end)
+
     :ok
   end
 
   test "can log" do
-    Logger.info "hello world", [key1: "field1"]
+    Logger.info("hello world", key1: "field1")
     json = get_log()
-    {:ok, data} = JSX.decode json
+    {:ok, data} = Jason.decode(json)
     assert data["type"] === "some_app"
     assert data["message"] === "hello world"
+
     expected = %{
       "function" => "test can log/1",
       "level" => "info",
       "module" => "Elixir.LoggerLogstashBackendTest",
-      "pid" => (inspect self()),
+      "pid" => inspect(self()),
       "some_metadata" => "go here",
-      "line" => 42,
+      "line" => 45,
       "key1" => "field1"
     }
+
+    assert data["fields"]["line"] == expected["line"]
     assert contains?(data["fields"], expected)
-    {:ok, ts} = Timex.parse data["@timestamp"], "{ISO:Extended}"
-    ts = Timex.to_unix ts
+    {:ok, dt, _tz_offset} = DateTime.from_iso8601(data["@timestamp"])
+    ts = DateTime.to_unix(dt)
 
-    now = Timex.to_unix Timex.local
-    assert (now - ts) < 1000
+    now = DateTime.utc_now() |> DateTime.to_unix()
+    assert now - ts < 1000
   end
 
   test "can log pids" do
-    Logger.info "pid", [pid_key: self()]
+    Logger.info("pid", pid_key: self())
     json = get_log()
-    {:ok, data} = JSX.decode json
+    {:ok, data} = Jason.decode(json)
     assert data["type"] === "some_app"
     assert data["message"] === "pid"
+
     expected = %{
       "function" => "test can log pids/1",
       "level" => "info",
       "module" => "Elixir.LoggerLogstashBackendTest",
-      "pid" => (inspect self()),
+      "pid" => inspect(self()),
       "pid_key" => inspect(self()),
       "some_metadata" => "go here",
-      "line" => 65
+      "line" => 71
     }
+
+    assert data["fields"]["line"] == expected["line"]
     assert contains?(data["fields"], expected)
-    {:ok, ts} = Timex.parse data["@timestamp"], "{ISO:Extended}"
-    ts = Timex.to_unix ts
+    {:ok, dt, _tz_offset} = DateTime.from_iso8601(data["@timestamp"])
+    ts = DateTime.to_unix(dt)
 
-    now = Timex.to_unix Timex.local
-    assert (now - ts) < 1000
+    now = DateTime.utc_now() |> DateTime.to_unix()
+    assert now - ts < 1000
   end
 
   test "cant log when minor levels" do
-    Logger.debug "hello world", [key1: "field1"]
+    Logger.debug("hello world", key1: "field1")
     :nothing_received = get_log()
   end
 
   defp get_log do
     receive do
       {:udp, _, _, _, json} -> json
-    after 500 -> :nothing_received
+    after
+      500 -> :nothing_received
     end
   end
 

From fa2138806f7e34a79621edf8f77c61a7afd53f9b Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Thu, 19 Apr 2018 11:31:12 +0200
Subject: [PATCH 02/17] Update TravisCI build targets

---
 .travis.yml | 2 --
 mix.exs     | 2 +-
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index a8a0f95..8d14536 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,6 @@
 language: elixir
 elixir:
-  - 1.3.0
   - 1.4.0
   - 1.5.0
 otp_release:
   - 18.0
-
diff --git a/mix.exs b/mix.exs
index a5bd852..b30b221 100644
--- a/mix.exs
+++ b/mix.exs
@@ -7,7 +7,7 @@ defmodule LoggerLogstashBackend.Mixfile do
       name: "logger_logstash_backend",
       source_url: "https://github.com/marcelog/logger_logstash_backend",
       version: "5.0.0",
-      elixir: "~> 1.3",
+      elixir: "~> 1.4",
       description: description(),
       package: package(),
       deps: deps()

From 29ead759f293bddfbc4059bd949c686e0f792ed1 Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Mon, 11 Jun 2018 11:50:34 +0200
Subject: [PATCH 03/17] Clean up deps & add note to install `Jason` to use it.

---
 README.md |  2 +-
 mix.exs   |  2 +-
 mix.lock  | 12 ------------
 3 files changed, 2 insertions(+), 14 deletions(-)

diff --git a/README.md b/README.md
index 8b71913..825225c 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ that will send logs to the [Logstash UDP input](https://www.elastic.co/guide/en/
  * **level**: Atom. Minimum level for this backend.
  * **type**: String.t. Type of logs. Useful to filter in logstash.
  * **timezone**: String.t. Server timezone. Used to convert from naive timestamp. Default `"Etc/UTC"`.
- * **json_encoder**: Atom. Module to be used for JSON encoding. Default `Jason`.
+ * **json_encoder**: Atom. Module to be used for JSON encoding. The default is `Jason`, add it to your mix deps to use.
 
 ## Sample Logstash config
 ```
diff --git a/mix.exs b/mix.exs
index b30b221..7657755 100644
--- a/mix.exs
+++ b/mix.exs
@@ -22,7 +22,7 @@ defmodule LoggerLogstashBackend.Mixfile do
     [
       {:earmark, "~> 1.0.3", only: :dev},
       {:ex_doc, "~> 0.14.5", only: :dev},
-      {:jason, "~> 1.0", only: [:dev, :test]}
+      {:jason, "~> 1.0", only: [:test]}
     ]
   end
 
diff --git a/mix.lock b/mix.lock
index 0794cbc..afe91c3 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,17 +1,5 @@
 %{
-  "certifi": {:hex, :certifi, "0.7.0", "861a57f3808f7eb0c2d1802afeaae0fa5de813b0df0979153cbafcd853ababaf", [:rebar3], []},
-  "combine": {:hex, :combine, "0.9.6", "8d1034a127d4cbf6924c8a5010d3534d958085575fa4d9b878f200d79ac78335", [:mix], []},
   "earmark": {:hex, :earmark, "1.0.3", "89bdbaf2aca8bbb5c97d8b3b55c5dd0cff517ecc78d417e87f1d0982e514557b", [:mix], []},
   "ex_doc": {:hex, :ex_doc, "0.14.5", "c0433c8117e948404d93ca69411dd575ec6be39b47802e81ca8d91017a0cf83c", [:mix], [{:earmark, "~> 1.0", [hex: :earmark, optional: false]}]},
-  "exjsx": {:hex, :exjsx, "3.2.1", "1bc5bf1e4fd249104178f0885030bcd75a4526f4d2a1e976f4b428d347614f0f", [:mix], [{:jsx, "~> 2.8.0", [hex: :jsx, optional: false]}]},
-  "gettext": {:hex, :gettext, "0.13.0", "daafbddc5cda12738bb93b01d84105fe75b916a302f1c50ab9fb066b95ec9db4", [:mix], []},
-  "hackney": {:hex, :hackney, "1.6.5", "8c025ee397ac94a184b0743c73b33b96465e85f90a02e210e86df6cbafaa5065", [:rebar3], [{:certifi, "0.7.0", [hex: :certifi, optional: false]}, {:idna, "1.2.0", [hex: :idna, optional: false]}, {:metrics, "1.0.1", [hex: :metrics, optional: false]}, {:mimerl, "1.0.2", [hex: :mimerl, optional: false]}, {:ssl_verify_fun, "1.1.1", [hex: :ssl_verify_fun, optional: false]}]},
-  "idna": {:hex, :idna, "1.2.0", "ac62ee99da068f43c50dc69acf700e03a62a348360126260e87f2b54eced86b2", [:rebar3], []},
   "jason": {:hex, :jason, "1.0.0", "0f7cfa9bdb23fed721ec05419bcee2b2c21a77e926bce0deda029b5adc716fe2", [:mix], [{:decimal, "~> 1.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm"},
-  "jsx": {:hex, :jsx, "2.8.1", "1453b4eb3615acb3e2cd0a105d27e6761e2ed2e501ac0b390f5bbec497669846", [:mix, :rebar3], []},
-  "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [:rebar3], []},
-  "mimerl": {:hex, :mimerl, "1.0.2", "993f9b0e084083405ed8252b99460c4f0563e41729ab42d9074fd5e52439be88", [:rebar3], []},
-  "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.1", "28a4d65b7f59893bc2c7de786dec1e1555bd742d336043fe644ae956c3497fbe", [:make, :rebar], []},
-  "timex": {:hex, :timex, "3.1.8", "a32f636c4260dd7515a3767be3d3a163dc09d15f0e9e689254b7bab152b29209", [:mix], [{:combine, "~> 0.7", [hex: :combine, optional: false]}, {:gettext, "~> 0.10", [hex: :gettext, optional: false]}, {:tzdata, "~> 0.1.8 or ~> 0.5", [hex: :tzdata, optional: false]}]},
-  "tzdata": {:hex, :tzdata, "0.5.10", "087e8dfe8c0283473115ad8ca6974b898ecb55ca5c725427a142a79593391e90", [:mix], [{:hackney, "~> 1.0", [hex: :hackney, optional: false]}]},
 }

From 31ba9ea1d992515bbb58dc04d1e73cb4dd8e8496 Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Wed, 27 Jun 2018 13:14:47 +0200
Subject: [PATCH 04/17] Allow configuring protocol and add :tcp as option

---
 lib/logger_logstash_backend.ex | 45 ++++++++++++++++++++++++----------
 1 file changed, 32 insertions(+), 13 deletions(-)

diff --git a/lib/logger_logstash_backend.ex b/lib/logger_logstash_backend.ex
index ca357f5..873346e 100644
--- a/lib/logger_logstash_backend.ex
+++ b/lib/logger_logstash_backend.ex
@@ -51,15 +51,13 @@ defmodule LoggerLogstashBackend do
     :ok
   end
 
-  defp log_event(level, msg, ts, md, %{
-         host: host,
-         port: port,
-         type: type,
-         metadata: metadata,
-         socket: socket,
-         timezone: timezone,
-         json_encoder: json_encoder
-       }) do
+  defp log_event(
+         level,
+         msg,
+         ts,
+         md,
+         %{type: type, metadata: metadata, timezone: timezone, json_encoder: json_encoder} = state
+       ) do
     fields =
       md
       |> Keyword.merge(metadata)
@@ -90,7 +88,15 @@ defmodule LoggerLogstashBackend do
         fields: fields
       })
 
-    :gen_udp.send(socket, host, port, to_charlist(json))
+    send_log(state, json)
+  end
+
+  defp send_log(%{protocol: :udp, socket: socket, host: host, port: port} = state, json) do
+    :gen_udp.send(socket, host, port, [json, "\n"])
+  end
+
+  defp send_log(%{protocol: :tcp, socket: socket} = state, json) do
+    :gen_tcp.send(socket, [json, "\n"])
   end
 
   defp configure(name, opts) do
@@ -105,19 +111,32 @@ defmodule LoggerLogstashBackend do
     port = Keyword.get(opts, :port)
     timezone = Keyword.get(opts, :timezone, "Etc/UTC")
     json_encoder = Keyword.get(opts, :json_encoder, Jason)
-    {:ok, socket} = :gen_udp.open(0)
+    protocol = Keyword.get(opts, :protocol, :udp)
 
     %{
       name: name,
       host: to_charlist(host),
       port: port,
       level: level,
-      socket: socket,
       type: type,
       metadata: metadata,
       timezone: timezone,
-      json_encoder: json_encoder
+      json_encoder: json_encoder,
+      protocol: protocol
     }
+    |> open_socket()
+  end
+
+  defp open_socket(%{protocol: :udp} = state) do
+    {:ok, socket} = :gen_udp.open(0)
+    Map.put(state, :socket, socket)
+  end
+
+  defp open_socket(%{protocol: :tcp} = state) do
+    {:ok, socket} =
+      :gen_tcp.connect(state.host, state.port, [{:active, true}, :binary, {:keepalive, true}])
+
+    Map.put(state, :socket, socket)
   end
 
   # inspects the argument only if it is a pid

From dcc5cbd4ff8de12acb551538c3300f5347265578 Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Wed, 27 Jun 2018 13:38:31 +0200
Subject: [PATCH 05/17] Add support for TLS connections

---
 lib/logger_logstash_backend.ex | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/lib/logger_logstash_backend.ex b/lib/logger_logstash_backend.ex
index 873346e..5694f18 100644
--- a/lib/logger_logstash_backend.ex
+++ b/lib/logger_logstash_backend.ex
@@ -95,6 +95,10 @@ defmodule LoggerLogstashBackend do
     :gen_udp.send(socket, host, port, [json, "\n"])
   end
 
+  defp send_log(%{protocol: :tcp, ssl: true, socket: socket} = state, json) do
+    :ssl.send(socket, [json, "\n"])
+  end
+
   defp send_log(%{protocol: :tcp, socket: socket} = state, json) do
     :gen_tcp.send(socket, [json, "\n"])
   end
@@ -112,6 +116,11 @@ defmodule LoggerLogstashBackend do
     timezone = Keyword.get(opts, :timezone, "Etc/UTC")
     json_encoder = Keyword.get(opts, :json_encoder, Jason)
     protocol = Keyword.get(opts, :protocol, :udp)
+    ssl = Keyword.get(opts, :ssl, false)
+
+    if ssl && protocol == :udp do
+      raise ArgumentError, message: "cannot use SSL in combination with UDP. Use TCP instead"
+    end
 
     %{
       name: name,
@@ -122,7 +131,8 @@ defmodule LoggerLogstashBackend do
       metadata: metadata,
       timezone: timezone,
       json_encoder: json_encoder,
-      protocol: protocol
+      protocol: protocol,
+      ssl: ssl
     }
     |> open_socket()
   end
@@ -132,6 +142,14 @@ defmodule LoggerLogstashBackend do
     Map.put(state, :socket, socket)
   end
 
+  defp open_socket(%{protocol: :tcp, ssl: true} = state) do
+    {:ok, socket} =
+      :gen_tcp.connect(state.host, state.port, [{:active, true}, :binary, {:keepalive, true}])
+
+    socket = :ssl.connect(socket, fail_if_no_peer_cert: true)
+    Map.put(state, :socket, socket)
+  end
+
   defp open_socket(%{protocol: :tcp} = state) do
     {:ok, socket} =
       :gen_tcp.connect(state.host, state.port, [{:active, true}, :binary, {:keepalive, true}])

From 72495791cbf0dffd1e84536a8bdd32e5b5274cce Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Wed, 27 Jun 2018 13:40:27 +0200
Subject: [PATCH 06/17] Remove unused variables

---
 lib/logger_logstash_backend.ex | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/logger_logstash_backend.ex b/lib/logger_logstash_backend.ex
index 5694f18..cc64031 100644
--- a/lib/logger_logstash_backend.ex
+++ b/lib/logger_logstash_backend.ex
@@ -91,15 +91,15 @@ defmodule LoggerLogstashBackend do
     send_log(state, json)
   end
 
-  defp send_log(%{protocol: :udp, socket: socket, host: host, port: port} = state, json) do
+  defp send_log(%{protocol: :udp, socket: socket, host: host, port: port}, json) do
     :gen_udp.send(socket, host, port, [json, "\n"])
   end
 
-  defp send_log(%{protocol: :tcp, ssl: true, socket: socket} = state, json) do
+  defp send_log(%{protocol: :tcp, ssl: true, socket: socket}, json) do
     :ssl.send(socket, [json, "\n"])
   end
 
-  defp send_log(%{protocol: :tcp, socket: socket} = state, json) do
+  defp send_log(%{protocol: :tcp, socket: socket}, json) do
     :gen_tcp.send(socket, [json, "\n"])
   end
 

From 4ade7c557e3d1c483d7b9d09b7b57f052a34cb22 Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Wed, 27 Jun 2018 13:42:16 +0200
Subject: [PATCH 07/17] Pattern match output of :ssl.connect/2

---
 lib/logger_logstash_backend.ex | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/logger_logstash_backend.ex b/lib/logger_logstash_backend.ex
index cc64031..fc5366f 100644
--- a/lib/logger_logstash_backend.ex
+++ b/lib/logger_logstash_backend.ex
@@ -146,7 +146,7 @@ defmodule LoggerLogstashBackend do
     {:ok, socket} =
       :gen_tcp.connect(state.host, state.port, [{:active, true}, :binary, {:keepalive, true}])
 
-    socket = :ssl.connect(socket, fail_if_no_peer_cert: true)
+    {:ok, socket} = :ssl.connect(socket, fail_if_no_peer_cert: true)
     Map.put(state, :socket, socket)
   end
 

From 801101504f19c107f417e9b2598ae257d1bd7d35 Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Wed, 27 Jun 2018 13:48:17 +0200
Subject: [PATCH 08/17] Match on output of `send` functions

---
 lib/logger_logstash_backend.ex | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/logger_logstash_backend.ex b/lib/logger_logstash_backend.ex
index fc5366f..ee60b43 100644
--- a/lib/logger_logstash_backend.ex
+++ b/lib/logger_logstash_backend.ex
@@ -92,15 +92,15 @@ defmodule LoggerLogstashBackend do
   end
 
   defp send_log(%{protocol: :udp, socket: socket, host: host, port: port}, json) do
-    :gen_udp.send(socket, host, port, [json, "\n"])
+    :ok = :gen_udp.send(socket, host, port, [json, "\n"])
   end
 
   defp send_log(%{protocol: :tcp, ssl: true, socket: socket}, json) do
-    :ssl.send(socket, [json, "\n"])
+    :ok = :ssl.send(socket, [json, "\n"])
   end
 
   defp send_log(%{protocol: :tcp, socket: socket}, json) do
-    :gen_tcp.send(socket, [json, "\n"])
+    :ok = :gen_tcp.send(socket, [json, "\n"])
   end
 
   defp configure(name, opts) do

From ea1d9e454902ae538e8079d1f81c636b59a4d2d6 Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Wed, 27 Jun 2018 13:56:08 +0200
Subject: [PATCH 09/17] Add fields to top level

---
 lib/logger_logstash_backend.ex | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/lib/logger_logstash_backend.ex b/lib/logger_logstash_backend.ex
index ee60b43..62f9863 100644
--- a/lib/logger_logstash_backend.ex
+++ b/lib/logger_logstash_backend.ex
@@ -80,13 +80,17 @@ defmodule LoggerLogstashBackend do
 
     {:ok, datetime} = DateTime.from_naive(ts, timezone)
 
-    {:ok, json} =
-      json_encoder.encode(%{
-        type: type,
-        "@timestamp": DateTime.to_iso8601(datetime),
-        message: to_string(msg),
-        fields: fields
-      })
+    message =
+      Map.merge(
+        %{
+          type: type,
+          "@timestamp": DateTime.to_iso8601(datetime),
+          message: to_string(msg)
+        },
+        fields
+      )
+
+    {:ok, json} = json_encoder.encode(message)
 
     send_log(state, json)
   end

From 54bec9563407c1ca77f19b0647402527228d2c02 Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Wed, 27 Jun 2018 15:28:29 +0200
Subject: [PATCH 10/17] Update tests to reflect fields being merged directly
 into json

---
 test/logger_logstash_backend_test.exs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/test/logger_logstash_backend_test.exs b/test/logger_logstash_backend_test.exs
index d1335b1..6dcac91 100644
--- a/test/logger_logstash_backend_test.exs
+++ b/test/logger_logstash_backend_test.exs
@@ -58,8 +58,8 @@ defmodule LoggerLogstashBackendTest do
       "key1" => "field1"
     }
 
-    assert data["fields"]["line"] == expected["line"]
-    assert contains?(data["fields"], expected)
+    assert data["line"] == expected["line"]
+    assert contains?(data, expected)
     {:ok, dt, _tz_offset} = DateTime.from_iso8601(data["@timestamp"])
     ts = DateTime.to_unix(dt)
 
@@ -84,8 +84,8 @@ defmodule LoggerLogstashBackendTest do
       "line" => 71
     }
 
-    assert data["fields"]["line"] == expected["line"]
-    assert contains?(data["fields"], expected)
+    assert data["line"] == expected["line"]
+    assert contains?(data, expected)
     {:ok, dt, _tz_offset} = DateTime.from_iso8601(data["@timestamp"])
     ts = DateTime.to_unix(dt)
 

From 4f9f1b720ba6dcfd21b9d4c85d798cd7a9847b5f Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Fri, 20 Jul 2018 09:18:23 +0200
Subject: [PATCH 11/17] Handle unavailable connections by attempting reconnect
 on every log

---
 lib/logger_logstash_backend.ex | 70 +++++++++++++++++++++++++---------
 1 file changed, 53 insertions(+), 17 deletions(-)

diff --git a/lib/logger_logstash_backend.ex b/lib/logger_logstash_backend.ex
index 62f9863..1ab7786 100644
--- a/lib/logger_logstash_backend.ex
+++ b/lib/logger_logstash_backend.ex
@@ -16,11 +16,14 @@
 defmodule LoggerLogstashBackend do
   @behaviour :gen_event
 
+  require Logger
+
   def init({__MODULE__, name}) do
     {:ok, configure(name, [])}
   end
 
-  def handle_call({:configure, opts}, %{name: name}) do
+  def handle_call({:configure, opts}, %{name: name} = state) do
+    close_socket(state)
     {:ok, :ok, configure(name, opts)}
   end
 
@@ -36,11 +39,13 @@ defmodule LoggerLogstashBackend do
         {level, _gl, {Logger, msg, ts, md}},
         %{level: min_level} = state
       ) do
+    new_state = open_socket(state)
+
     if is_nil(min_level) or Logger.compare_levels(level, min_level) != :lt do
-      log_event(level, msg, ts, md, state)
+      log_event(level, msg, ts, md, new_state)
     end
 
-    {:ok, state}
+    {:ok, new_state}
   end
 
   def code_change(_old_vsn, state, _extra) do
@@ -95,6 +100,8 @@ defmodule LoggerLogstashBackend do
     send_log(state, json)
   end
 
+  defp send_log(%{socket: nil}, _json), do: nil
+
   defp send_log(%{protocol: :udp, socket: socket, host: host, port: port}, json) do
     :ok = :gen_udp.send(socket, host, port, [json, "\n"])
   end
@@ -136,31 +143,60 @@ defmodule LoggerLogstashBackend do
       timezone: timezone,
       json_encoder: json_encoder,
       protocol: protocol,
-      ssl: ssl
+      ssl: ssl,
+      socket: nil
     }
-    |> open_socket()
   end
 
-  defp open_socket(%{protocol: :udp} = state) do
-    {:ok, socket} = :gen_udp.open(0)
-    Map.put(state, :socket, socket)
+  defp close_socket(%{socket: nil} = state), do: state
+
+  defp close_socket(%{protocol: :udp} = state) do
+    :ok = :gen_udp.close(state.socket)
+    %{state | socket: nil}
+  end
+
+  defp close_socket(%{protocol: :tcp} = state) do
+    :gen_tcp.shutdown(state.socket, :write)
+    %{state | socket: nil}
   end
 
-  defp open_socket(%{protocol: :tcp, ssl: true} = state) do
-    {:ok, socket} =
-      :gen_tcp.connect(state.host, state.port, [{:active, true}, :binary, {:keepalive, true}])
+  defp open_socket(%{protocol: :udp, socket: nil} = state) do
+    case :gen_udp.open(0) do
+      {:ok, socket} ->
+        Map.put(state, :socket, socket)
 
-    {:ok, socket} = :ssl.connect(socket, fail_if_no_peer_cert: true)
-    Map.put(state, :socket, socket)
+      {:error, reason} ->
+        Logger.info("could not connect to logstash via udp, reason: #{inspect(reason)}")
+        state
+    end
+  end
+
+  defp open_socket(%{protocol: :tcp, ssl: true, socket: nil} = state) do
+    with {:ok, socket} <-
+           :gen_tcp.connect(state.host, state.port, [{:active, true}, :binary, {:keepalive, true}]),
+         {:ok, socket} <- :ssl.connect(socket, fail_if_no_peer_cert: true) do
+      Map.put(state, :socket, socket)
+    else
+      {:error, reason} ->
+        Logger.info("could not connect via tcp (with ssl), reason: #{inspect(reason)}")
+        state
+    end
   end
 
-  defp open_socket(%{protocol: :tcp} = state) do
-    {:ok, socket} =
-      :gen_tcp.connect(state.host, state.port, [{:active, true}, :binary, {:keepalive, true}])
+  defp open_socket(%{protocol: :tcp, socket: nil} = state) do
+    :gen_tcp.connect(state.host, state.port, [{:active, true}, :binary, {:keepalive, true}])
+    |> case do
+      {:ok, socket} ->
+        Map.put(state, :socket, socket)
 
-    Map.put(state, :socket, socket)
+      {:error, reason} ->
+        Logger.info("could not connect via tcp, reason: #{inspect(reason)}")
+        state
+    end
   end
 
+  defp open_socket(state), do: state
+
   # inspects the argument only if it is a pid
   defp inspect_pid(pid) when is_pid(pid), do: inspect(pid)
   defp inspect_pid(other), do: other

From 42fa0022ba84e0b6224060d4fbfc1393abee42e6 Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Fri, 20 Jul 2018 09:34:00 +0200
Subject: [PATCH 12/17] Only log error once

---
 lib/logger_logstash_backend.ex | 33 +++++++++++++++++----------------
 1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/lib/logger_logstash_backend.ex b/lib/logger_logstash_backend.ex
index 1ab7786..280c34a 100644
--- a/lib/logger_logstash_backend.ex
+++ b/lib/logger_logstash_backend.ex
@@ -144,7 +144,8 @@ defmodule LoggerLogstashBackend do
       json_encoder: json_encoder,
       protocol: protocol,
       ssl: ssl,
-      socket: nil
+      socket: nil,
+      recorded_error: false
     }
   end
 
@@ -160,14 +161,20 @@ defmodule LoggerLogstashBackend do
     %{state | socket: nil}
   end
 
+  defp log_error(error, %{recorded_error: false} = state) do
+    Logger.info(
+      "could not connect to logstash via #{inspect(state.protocol)}, reason: #{inspect(error)}"
+    )
+
+    %{state | recorded_error: true}
+  end
+
+  defp log_error(_error, state), do: state
+
   defp open_socket(%{protocol: :udp, socket: nil} = state) do
     case :gen_udp.open(0) do
-      {:ok, socket} ->
-        Map.put(state, :socket, socket)
-
-      {:error, reason} ->
-        Logger.info("could not connect to logstash via udp, reason: #{inspect(reason)}")
-        state
+      {:ok, socket} -> Map.put(state, :socket, socket)
+      {:error, reason} -> log_error(reason, state)
     end
   end
 
@@ -177,21 +184,15 @@ defmodule LoggerLogstashBackend do
          {:ok, socket} <- :ssl.connect(socket, fail_if_no_peer_cert: true) do
       Map.put(state, :socket, socket)
     else
-      {:error, reason} ->
-        Logger.info("could not connect via tcp (with ssl), reason: #{inspect(reason)}")
-        state
+      {:error, reason} -> log_error(reason, state)
     end
   end
 
   defp open_socket(%{protocol: :tcp, socket: nil} = state) do
     :gen_tcp.connect(state.host, state.port, [{:active, true}, :binary, {:keepalive, true}])
     |> case do
-      {:ok, socket} ->
-        Map.put(state, :socket, socket)
-
-      {:error, reason} ->
-        Logger.info("could not connect via tcp, reason: #{inspect(reason)}")
-        state
+      {:ok, socket} -> Map.put(state, :socket, socket)
+      {:error, reason} -> log_error(reason, state)
     end
   end
 

From bde392e0994bb39098ac328ad58049db3eb45e2f Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Fri, 20 Jul 2018 09:36:43 +0200
Subject: [PATCH 13/17] Log as error

---
 lib/logger_logstash_backend.ex | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/logger_logstash_backend.ex b/lib/logger_logstash_backend.ex
index 280c34a..7861c85 100644
--- a/lib/logger_logstash_backend.ex
+++ b/lib/logger_logstash_backend.ex
@@ -162,7 +162,7 @@ defmodule LoggerLogstashBackend do
   end
 
   defp log_error(error, %{recorded_error: false} = state) do
-    Logger.info(
+    Logger.error(
       "could not connect to logstash via #{inspect(state.protocol)}, reason: #{inspect(error)}"
     )
 

From 8f87e86fd917ce382472406e4b0ad62a2692bbbf Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Fri, 20 Jul 2018 10:03:28 +0200
Subject: [PATCH 14/17] Reset recorded_error when connection has been made

---
 lib/logger_logstash_backend.ex | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/logger_logstash_backend.ex b/lib/logger_logstash_backend.ex
index 7861c85..0619266 100644
--- a/lib/logger_logstash_backend.ex
+++ b/lib/logger_logstash_backend.ex
@@ -173,7 +173,7 @@ defmodule LoggerLogstashBackend do
 
   defp open_socket(%{protocol: :udp, socket: nil} = state) do
     case :gen_udp.open(0) do
-      {:ok, socket} -> Map.put(state, :socket, socket)
+      {:ok, socket} -> Map.merge(state, %{socket: socket, recorded_error: false})
       {:error, reason} -> log_error(reason, state)
     end
   end
@@ -182,7 +182,7 @@ defmodule LoggerLogstashBackend do
     with {:ok, socket} <-
            :gen_tcp.connect(state.host, state.port, [{:active, true}, :binary, {:keepalive, true}]),
          {:ok, socket} <- :ssl.connect(socket, fail_if_no_peer_cert: true) do
-      Map.put(state, :socket, socket)
+      Map.merge(state, %{socket: socket, recorded_error: false})
     else
       {:error, reason} -> log_error(reason, state)
     end
@@ -191,7 +191,7 @@ defmodule LoggerLogstashBackend do
   defp open_socket(%{protocol: :tcp, socket: nil} = state) do
     :gen_tcp.connect(state.host, state.port, [{:active, true}, :binary, {:keepalive, true}])
     |> case do
-      {:ok, socket} -> Map.put(state, :socket, socket)
+      {:ok, socket} -> Map.merge(state, %{socket: socket, recorded_error: false})
       {:error, reason} -> log_error(reason, state)
     end
   end

From 2c0d0faa7b88fa39d4def3cbca75ba7dd6c04994 Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Wed, 29 Aug 2018 13:20:42 +0200
Subject: [PATCH 15/17] Set a connection timeout of 10s and a send timeout of
 10s.

The default value for connection timeout is infinity, in my case it was
waiting for an hour before giving up, which is an awfully long time.
---
 lib/logger_logstash_backend.ex | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/logger_logstash_backend.ex b/lib/logger_logstash_backend.ex
index 0619266..c45702d 100644
--- a/lib/logger_logstash_backend.ex
+++ b/lib/logger_logstash_backend.ex
@@ -189,7 +189,12 @@ defmodule LoggerLogstashBackend do
   end
 
   defp open_socket(%{protocol: :tcp, socket: nil} = state) do
-    :gen_tcp.connect(state.host, state.port, [{:active, true}, :binary, {:keepalive, true}])
+    :gen_tcp.connect(
+      state.host,
+      state.port,
+      [{:active, true}, :binary, {:keepalive, true}, {:send_timeout, 10_000}],
+      10_000
+    )
     |> case do
       {:ok, socket} -> Map.merge(state, %{socket: socket, recorded_error: false})
       {:error, reason} -> log_error(reason, state)

From 0ef890dd84907b3e34a59fa235e74b416fef9fc4 Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Tue, 16 Oct 2018 15:22:08 +0200
Subject: [PATCH 16/17] Handle closed connections (log error and mark socket as
 closed)

---
 lib/logger_logstash_backend.ex | 44 ++++++++++++++++++++++++++--------
 1 file changed, 34 insertions(+), 10 deletions(-)

diff --git a/lib/logger_logstash_backend.ex b/lib/logger_logstash_backend.ex
index c45702d..bc49df0 100644
--- a/lib/logger_logstash_backend.ex
+++ b/lib/logger_logstash_backend.ex
@@ -41,9 +41,12 @@ defmodule LoggerLogstashBackend do
       ) do
     new_state = open_socket(state)
 
-    if is_nil(min_level) or Logger.compare_levels(level, min_level) != :lt do
-      log_event(level, msg, ts, md, new_state)
-    end
+    new_state =
+      if is_nil(min_level) or Logger.compare_levels(level, min_level) != :lt do
+        log_event(level, msg, ts, md, new_state)
+      else
+        new_state
+      end
 
     {:ok, new_state}
   end
@@ -100,18 +103,39 @@ defmodule LoggerLogstashBackend do
     send_log(state, json)
   end
 
-  defp send_log(%{socket: nil}, _json), do: nil
+  defp send_log(%{socket: nil} = state, _json), do: state
+
+  defp send_log(%{protocol: :udp, socket: socket, host: host, port: port} = state, json) do
+    case :gen_udp.send(socket, host, port, [json, "\n"]) do
+      :ok ->
+        state
 
-  defp send_log(%{protocol: :udp, socket: socket, host: host, port: port}, json) do
-    :ok = :gen_udp.send(socket, host, port, [json, "\n"])
+      {:error, :closed} ->
+        log_error(:closed, state)
+        %{state | socket: nil}
+    end
   end
 
-  defp send_log(%{protocol: :tcp, ssl: true, socket: socket}, json) do
-    :ok = :ssl.send(socket, [json, "\n"])
+  defp send_log(%{protocol: :tcp, ssl: true, socket: socket} = state, json) do
+    case :ssl.send(socket, [json, "\n"]) do
+      :ok ->
+        state
+
+      {:error, :closed} ->
+        log_error(:closed, state)
+        %{state | socket: nil}
+    end
   end
 
-  defp send_log(%{protocol: :tcp, socket: socket}, json) do
-    :ok = :gen_tcp.send(socket, [json, "\n"])
+  defp send_log(%{protocol: :tcp, socket: socket} = state, json) do
+    case :gen_tcp.send(socket, [json, "\n"]) do
+      :ok ->
+        state
+
+      {:error, :closed} ->
+        log_error(:closed, state)
+        %{state | socket: nil}
+    end
   end
 
   defp configure(name, opts) do

From 1fbe5796de8f9d9d3aaef87c0fe0d98daea46b76 Mon Sep 17 00:00:00 2001
From: Derek Kraan <derek.kraan@gmail.com>
Date: Fri, 23 Nov 2018 13:21:05 +0100
Subject: [PATCH 17/17] Specify timeout for :ssl.connect (and reduce other
 timeouts)

---
 lib/logger_logstash_backend.ex | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/lib/logger_logstash_backend.ex b/lib/logger_logstash_backend.ex
index bc49df0..9fe8d0b 100644
--- a/lib/logger_logstash_backend.ex
+++ b/lib/logger_logstash_backend.ex
@@ -204,8 +204,14 @@ defmodule LoggerLogstashBackend do
 
   defp open_socket(%{protocol: :tcp, ssl: true, socket: nil} = state) do
     with {:ok, socket} <-
-           :gen_tcp.connect(state.host, state.port, [{:active, true}, :binary, {:keepalive, true}]),
-         {:ok, socket} <- :ssl.connect(socket, fail_if_no_peer_cert: true) do
+           :gen_tcp.connect(state.host, state.port, [
+             {:active, true},
+             :binary,
+             {:keepalive, true},
+             {:send_timeout, 5000},
+             {:send_timeout_close, true}
+           ]),
+         {:ok, socket} <- :ssl.connect(socket, [fail_if_no_peer_cert: true], 5000) do
       Map.merge(state, %{socket: socket, recorded_error: false})
     else
       {:error, reason} -> log_error(reason, state)
@@ -216,8 +222,14 @@ defmodule LoggerLogstashBackend do
     :gen_tcp.connect(
       state.host,
       state.port,
-      [{:active, true}, :binary, {:keepalive, true}, {:send_timeout, 10_000}],
-      10_000
+      [
+        {:active, true},
+        :binary,
+        {:keepalive, true},
+        {:send_timeout, 5000},
+        {:send_timeout_close, true}
+      ],
+      5000
     )
     |> case do
       {:ok, socket} -> Map.merge(state, %{socket: socket, recorded_error: false})