Class: Lens::Rails::LogExporter

Inherits:
Logger
  • Object
show all
Defined in:
lib/lens/rails/log_exporter.rb

Overview

Logger sink that batches log records and ships them to Lens via POST /v1/logs. Wired into Rails.logger via broadcast in the Railtie.

Constant Summary collapse

SEVERITY_TEXT = 
{
  ::Logger::DEBUG => "DEBUG",
  ::Logger::INFO => "INFO",
  ::Logger::WARN => "WARN",
  ::Logger::ERROR => "ERROR",
  ::Logger::FATAL => "FATAL",
  ::Logger::UNKNOWN => "UNKNOWN"
}.freeze
DROP_WARN_INTERVAL = 
60.0

Instance Method Summary collapse

Constructor Details

#initialize(url:, token:, service_name:, max_buffer: 10_000, min_severity: ::Logger::INFO, open_timeout: 2, read_timeout: 2) ⇒ LogExporter

Returns a new instance of LogExporter.



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# File 'lib/lens/rails/log_exporter.rb', line 22

def initialize(url:, token:, service_name:,
  max_buffer: 10_000,
  min_severity: ::Logger::INFO,
  open_timeout: 2,
  read_timeout: 2)
  super(File::NULL)
  @token = token
  @service_name = service_name
  @uri = URI("#{url}/v1/logs")
  @max_buffer = max_buffer
  @open_timeout = open_timeout
  @read_timeout = read_timeout
  @min_severity = min_severity
  @buffer = []
  @dropped = 0
  @last_drop_warn_at = 0.0
  @mutex = Mutex.new
  restart_flush_thread
  Lens::Rails.register_flushable(self)
end

Instance Method Details

#add(severity, message = nil, progname = nil, &block) ⇒ Object 



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# File 'lib/lens/rails/log_exporter.rb', line 43

def add(severity, message = nil, progname = nil, &block)
  return true if Thread.current[:lens_in_export]

  severity ||= ::Logger::UNKNOWN
  return true if severity < @min_severity

  message = block ? block.call : progname if message.nil?
  return true if message.nil?

  record = {
    timestamp: Time.now.iso8601(3),
    severity: SEVERITY_TEXT[severity] || "UNKNOWN",
    body: message.to_s.gsub(/\e\[[0-9;]*m/, ""),
    controller: Thread.current[:lens_controller],
    action: Thread.current[:lens_action],
    request_id: Thread.current[:lens_request_id]
  }.compact

  dropped_now = 0
  @mutex.synchronize do
    if @buffer.size >= @max_buffer
      @buffer.shift
      @dropped += 1
      dropped_now = @dropped
    end
    @buffer << record
  end

  maybe_warn_dropped(dropped_now) if dropped_now.positive?
  true
end

#flush ⇒ Object 



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# File 'lib/lens/rails/log_exporter.rb', line 75

def flush
  records = @mutex.synchronize { @buffer.tap { @buffer = [] } }
  return if records.empty?

  body = JSON.generate(logs: records, service: @service_name, version: Lens::Rails::VERSION)

  req = Net::HTTP::Post.new(@uri)
  req["Content-Type"] = "application/octet-stream"
  req["Authorization"] = "Bearer #{@token}"
  req.body = Zlib.gzip(body)

  Thread.current[:lens_in_export] = true
  begin
    Net::HTTP.start(@uri.host, @uri.port,
      use_ssl: @uri.scheme == "https",
      open_timeout: @open_timeout,
      read_timeout: @read_timeout) { |http| http.request(req) }
  ensure
    Thread.current[:lens_in_export] = false
  end
end

#restart_flush_thread ⇒ Object 



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# File 'lib/lens/rails/log_exporter.rb', line 102

def restart_flush_thread
  BackoffLoop.new(base: 5, max: 60, name: "lens-log-flush").start { flush }
end

#shutdown(timeout:) ⇒ Object 



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# File 'lib/lens/rails/log_exporter.rb', line 97

def shutdown(timeout:)
  Thread.new { flush }.join(timeout)
rescue
end