OpenTelemetryLogExporter

Sometimes you just wanna look at your spans 🤷🏻‍♂️

Inspired by shamelessly stolen from otel_exporter_stdout and circleci/ex. Span definition was pulled from here.

Example output:

[info] [span] 22ms "/teams/log_in" http.client_ip=127.0.0.1 http.flavor=:"1.1" http.method=GET http.scheme=http http.target=/teams/log_in net.host.name=localhost net.host.port=4000 net.peer.port=56526 net.sock.host.addr=127.0.0.1 net.sock.peer.addr=127.0.0.1 net.transport=:"IP.TCP" http.status_code=200 http.route=/teams/log_in phoenix.action=:new phoenix.plug=Phoenix.LiveView.Plug
[info] [span] 0ms "PearsWeb.TeamLoginLive.mount" name=nil
[info] [span] 0ms "pears.repo.query" source=nil db.instance=pears_dev db.statement=CREATE TABLE IF NOT EXISTS "schema_migrations" ("version" bigint, "inserted_at" timestamp(0), PRIMARY KEY ("version")) db.type=:sql db.url=ecto://localhost total_time_microseconds=597 decode_time_microseconds=1 idle_time_microseconds=997829 query_time_microseconds=201 queue_time_microseconds=394

Installation

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

def deps do
  [
    {:opentelemetry_log_exporter, "~> 0.5.0"}
  ]
end

and as a trace exporter in config/dev.exs.

config :opentelemetry, traces_exporter: {Elixir.OpenTelemetryLogExporter, [level: :info]}

You will need to change the scheduled delay in config/test.exs because by default the test process will exit before the spans are exported.

config :opentelemetry,
  processors: [
    {:otel_batch_processor, %{scheduled_delay_ms: 1, exporter: {Elixir.OpenTelemetryLogExporter, [level: :warning]}}}
  ]

You can change the level at which spans are logged by passing the :level keyword