Simple ruby lib for Google Cloud Trace

cloud_trace.rb

require 'securerandom'
require 'date'

require 'googleauth'
require 'google/apis/cloudtrace_v1'


class CloudTrace
  def initialize(project_id)
    @project_id = project_id
  end

  def start(span_name)
    @recorder = SpanRecorder.new(span_name)
  end

  def with_span(span_name)
    @recorder.with_span(span_name) { yield }
  end

  def publish
    spans = @recorder.spans
    spans.each { |s| puts s.inspect }
    trace = Google::Apis::CloudtraceV1::Trace.new(trace_id: new_trace_id, project_id: @project_id, spans: spans)
    traces = Google::Apis::CloudtraceV1::Traces.new(traces: [trace])
    service.patch_project_traces(@project_id, traces)
  end

  private

  def new_trace_id
    SecureRandom.uuid.split('-').join
  end

  def service
    service = Google::Apis::CloudtraceV1::CloudTraceService.new
    service.authorization = Google::Auth.get_application_default(['https://www.googleapis.com/auth/trace.append'])
    service
  end
end


class SpanRecorder
  def initialize(trace_name)
    @trace_name = trace_name

    @next_span_id = 0
    @mutex = Mutex.new

    @master_span = Google::Apis::CloudtraceV1::TraceSpan.new(
      name: @trace_name,
      span_id: next_span_id,
      start_time: now,
      end_time: nil,
      labels: {},
      kind: 'RPC_SERVER',
    )
    @spans = []
  end

  def with_span(span_name)
    start_time = now
    yield
    @spans << Google::Apis::CloudtraceV1::TraceSpan.new(
      name: span_name,
      span_id: next_span_id,
      parent_span_id: @master_span.span_id,
      start_time:  start_time,
      end_time: now,
      labels: {},
      kind: 'RPC_CLIENT',
    )
  end

  def spans
    @master_span.end_time = now
    [@master_span, *@spans]
  end

  private

  def next_span_id
    @mutex.synchronize { @next_span_id += 1 }
    @next_span_id.to_s
  end

  def now
    Time.now.utc.round(10).iso8601(6)
  end
end