README.md

logstash-json

Elixir Logger backend which sends logs to logstash in JSON format via TCP.

Also comes with a console logger.

Configuration

In mix.exs, add logstash_json as a dependency and to your applications:

def application do
  [applications: [:logger, :logstash_json]]
end

defp deps do
  [{:logstash, github: "svetob/logstash-json"}]
end

Logstash TCP logger backend

In config.exs add the TCP logger as a backend and configure it:

config :logger,
  backends: [
    :console,
    {LogstashJson.TCP, :logstash}
  ]

config :logger, :logstash,
  level: :debug,
  fields: %{appid: "my-app"},
  host: {:system, "LOGSTASH_TCP_HOST", "localhost"},
  port: {:system, "LOGSTASH_TCP_PORT", "4560"},
  workers: 2,
  buffer_size: 10_000

The parameters are:

• host: (Required) Logstash host.
• port: (Required) Logstash port.
• workers: Number of TCP workers, each worker opens a new TCP connection. (Default: 2)
• buffer_size: Size of internal message buffer, used when logs are generated faster than logstash can consume them. (Default: 10_000)
• fields: Additional fields to add to the JSON payload, such as appid. (Default: none)

The TCP logger handles various failure scenarios differently:

• If the internal message buffer fills up, logging new messages blocks until more messages are sent and there is space available in the buffer again.
• If the logstash connection is lost, logged messages are dropped.

Console logger backend

You can also log JSON to console if you'd like:

config :logger,
  backends: [
    {LogstashJson.Console, :json}
  ]

config :logger, :json,
  level: :debug

TODO list

• UDP appender?