README.md

Hummingbird

A plug to correlate events between services in a ✋ful lines of Elixir.

Given appropriate trace headers, ships an event for router and response calls.

Use Case

For reasons, you may not have access to configure structured logging and log shipping. If you can control your controller, this might help. It's dangerous out there, take this.

To Use

defmodule YourAppWeb.YourController do
  use YourAppWeb, :controller

  plug Hummingbird, service_name: "your_service_name"
end

and add the Hummingbird.Telemetry child to your supervision tree:

defmodule YouApp.Application do
  # ..

  def start(_type, _args) do
    children = [
      Hummingbird.Telemetry,
      # ..
    ]

    Supervisor.start_link(children, strategy: :one_for_one, name: YourApp.Supervisor)
  end

  # ..
end

Configuration

Configure OpenCensus

In your config.exs:

# configure opencensus
config :opencensus,
  reporters: [{Opencensus.Honeycomb.Reporter, []}],
  send_interval_ms: 1000

Set the dataset per environment

In your dev, prod, exs files:

# configure write key per dataset/environment
# we use environment variables to protect the secret. It doesn't matter how you
# set the value.  Choose your own adventure.

config :opencensus_honeycomb,
  dataset: "your_dataset_name_goes_here",
  write_key: "${HONEYCOMB_WRITE_KEY}"

Assumptions

Currently, it looks for x-b3-spanid and x-b3-traceid headers on incoming request to create the trace.

Current Example

Thanks

Wraps around https://github.com/open-telemetry/opentelemetry-erlang