LoggerJson

JSON console back-end for Elixir Logger.

It can be used as drop-in replacement for default :console Logger back-end in cases where you use use Google Cloud Logger or other JSON-based log collectors.

Log Format

Output JSON is compatible with Google Cloud Logger format with additional properties in serviceLocation and metadata objects:

{
   "time":"2017-04-09T17:52:12.497Z",
   "severity":"DEBUG",
   "sourceLocation":{
      "moduleName":"Elixir.LoggerJSONTest",
      "line":62,
      "functionName":"test metadata can be configured to :all/1",
      "file":"/Users/andrew/Projects/logger_json/test/unit/logger_json_test.exs"
   },
   "metadata":{
      "user_id":11,
      "dynamic_metadata":5
   },
   "logMessage":"hello"
}

Installation

It's available on Hex, the package can be installed as:

1. Add logger_json to your list of dependencies in mix.exs:

def deps do
  [{:logger_json, "~> 0.1.0"}]
end

1. Ensure logger_json is started before your application:

def application do
  [extra_applications: [:logger_json]]
end

1. Set a :json_encoder in your config/config.exs:

config :logger_json,
  backend: [json_encoder: Poison]

Dynamic configuration

For dynamically configuring the endpoint, such as loading data from environment variables or configuration files, LoggerJSON provides an :on_init option that allows developers to set a module, function and list of arguments that is invoked when the endpoint starts.

config :logger_json, :backend,
  on_init: {YourApp.Logger, :load_from_system_env, []}

Encoders support

You can replace default Poison encoder with other module that supports encode!/1 function. This can be even used as custom formatter callback.

Popular Poison alternatives:

• exjsx.
• elixir-json - native Elixir encoder implementation.

If your application is performance-critical, take look at jiffy.

Documentation

The docs can be found at https://hexdocs.pm/logger_json