Rails の Ruby 構造化イベント分析

# config/initializers/telemetry_requests.rb
require "json"
require "net/http"
require "uri"

module TelemetryRailsRequests
  def self.delivery_failed
    warn "Telemetry request event delivery failed."
  rescue StandardError
    # Diagnostics must not change the application result either.
  end

  def self.log(fields)
    key = ENV["TELEMETRY_API_KEY"]
    return if key.nil? || key.empty?

    uri = URI("https://api.telemetry.sh/log")
    request = Net::HTTP::Post.new(uri)
    request["Authorization"] = key
    request["Content-Type"] = "application/json"
    request.body = { table: "api_request_completed", data: fields }.to_json

    http = Net::HTTP.new(uri.host, uri.port)
    http.use_ssl = true
    http.open_timeout = 1
    http.read_timeout = 1
    http.write_timeout = 1
    http.max_retries = 0
    response = http.start { |client| client.request(request) }
    delivery_failed unless response.is_a?(Net::HTTPSuccess)
  rescue StandardError
    delivery_failed
  end
end

ActiveSupport::Notifications.monotonic_subscribe(
  "process_action.action_controller"
) do |_name, started, finished, _id, payload|
  status = payload[:status]
  status = nil unless status.is_a?(Integer) && (100..599).cover?(status)

  TelemetryRailsRequests.log({
    controller_action: "#{payload[:controller]}##{payload[:action]}",
    method: payload[:method],
    status_code: status,
    status: status ? "http_#{status / 100}xx" : "unknown",
    exception_observed: !!payload[:exception],
    latency_ms: ((finished - started) * 1000).round(2)
  })
rescue StandardError
  TelemetryRailsRequests.delivery_failed
end