Svadilfari

A logger backend for sending logs directly to Grafana Loki.

Installation

The package can be installed by adding svadilfari to your list of dependencies in mix.exs:

def deps do
  [
    {:svadilfari, "~> 0.1"}
  ]
end

Configure some parameters:

config :logger, :backends, [:console, Svadilfari]

config :logger, :svadilfari,
  metadata: [:user_id, :bogons],
  max_buffer: 10,
  client: [
    url: "http://localhost:3100",
    opts: [
      org_id: "tenant1"
    ]
  ],
  labels: [
    {"service", "svadilfari"},
    {"env", "dev"}
  ]

and start sending logs to Loki!

Configuration

A majority of configuration values works just like the :console logger, and more in-depth information on their function can be found here:

• level: The log level.
• format: The format message used to print logs. Defaults to "\n$time $metadata[$level] $levelpad$message\n".
• metadata: The metadata to be printed by $metadata.
• max_buffer: Maximum events to buffer while waiting for Loki to respond. Defaults to 32. Once full, the backend will block until Loki returns a success or error.

There are a few Loki-specific parameters:

• labels: A list of {String.t(), String.t()} tuples that represents Loki labels.
• client:
  • url: The Loki URL to send to. The /loki/api/v1/push path is inferred.
  • opts: Svadilfari uses the Sleipnir Loki client under the hood. Sleipnir Tesla Client args can be passed here.