@spec attach(
  name :: String.t(),
  event :: [atom()],
  level ::
    Logger.level()
    | {module :: module(), function :: atom(), arguments :: [term()]}
    | false
) :: :ok | {:error, :already_exists}

Attaches the telemetry handler to the given event.

Available options

• :level - log level which is used to log requests. Defaults to :info.

Dynamic log level

In some cases you may wish to set the log level dynamically on a per-query basis. To do so, set the :level option to a tuple, {Mod, Fun, Args}. The query and map of time measures will be prepended to the provided list of arguments.

When invoked, your function must return a Logger.level() or false to disable logging for the request.

Examples

Attaching the telemetry handler to the MyApp.Repo events with the :info log level:

LoggerJSON.Ecto.attach("logger-json-queries", [:my_app, :repo, :query], :info)

For more details on event and handler naming see (Ecto.Repo documentation)[https://hexdocs.pm/ecto/Ecto.Repo.html#module-telemetry-events].

@spec telemetry_logging_handler(
  event_name :: [atom()],
  measurements :: %{
    query_time: non_neg_integer(),
    queue_time: non_neg_integer(),
    decode_time: non_neg_integer(),
    total_time: non_neg_integer()
  },
  metadata :: %{query: String.t(), repo: module()},
  level ::
    Logger.level()
    | {module :: module(), function :: atom(), arguments :: [term()]}
    | false
) :: :ok

A telemetry handler that logs Ecto query along with it's metrics in a structured format.