#!/usr/bin/env ruby
# Reachability worker for datacenterbingo's status page (Bingo::Monitor).
# Runs as its own container from the asxpio image; the web container owns
# migrations, so this waits until the monitor tables exist.
require 'logger'
require 'fileutils'

$root   = File.expand_path('..', __dir__)
$logger = Logger.new($stdout)
$env    = ENV.fetch('RACK_ENV', 'development')
$stdout.sync = true

require_relative '../lib/db'
DB.connect!
until DB.connection.table_exists?(:bingo_monitor_buckets)
  $logger.info('monitor: waiting for migrations')
  sleep 10
end
require_relative '../lib/bingo'
require_relative '../lib/bingo_monitor'

HEARTBEAT = ENV.fetch('MONITOR_HEARTBEAT', '/tmp/monitor.heartbeat')
pruned_at = nil

loop do
  started = Time.now.utc
  begin
    targets = Bingo::Monitor::Target.where(active: true).all
    results = Bingo::Monitor.round(targets)
    Bingo::Monitor.record!(results, at: started)
    if pruned_at.nil? || started - pruned_at > 3600
      Bingo::Monitor.prune!(started)
      pruned_at = started
    end
    FileUtils.touch(HEARTBEAT)
    up = results.count { |_, ms| ms }
    $logger.info("monitor: #{up}/#{results.size} answered in #{(Time.now.utc - started).round(1)}s")
  rescue StandardError => e # a DB blip must not end the worker
    $logger.error("monitor: #{e.class}: #{e.message}")
  end
  sleep [Bingo::Monitor::INTERVAL - (Time.now.utc - started), 1].max
end