https://twitter.com/jhawthorn/status/982119046937174018

log_uptime.rb

# A stable ping target
# pretty much anything is more reliable than shaw
target_ip = "1.1.1.1"

# Maximum wait time in seconds.
wait = 1

interval = 10

require 'fileutils'

class BufferedLogByTime
  def initialize(dir, format="%F.log")
    FileUtils.mkdir_p dir
    @dir = dir
    @format = format

    @filename = nil
    @file = nil
    maybe_update_filename
  end

  def maybe_update_filename
    new_filename = Time.now.utc.strftime(@format)
    if new_filename != @filename
      @filename = new_filename

      @file.close if @file
      @file = File.open(File.join(@dir, @filename), 'w')
    end
  end

  def log(data)
    maybe_update_filename
    @file.puts data
    @file.flush
  end
end

logger = BufferedLogByTime.new("logs/")

loop do
  time_str = Time.now.utc.to_i

  result = `ping #{target_ip} -W #{wait} -c 1 -q`
  last_line = result.lines.last.strip
  if last_line.empty?
    logger.log "#{time_str},"
    puts "#{time_str}\tSHAW DOWN!"
  else
    time = last_line.split(' = ').last.split('/').first
    logger.log "#{time_str},#{time}"
    puts "#{time_str}\t#{time}ms"
  end

  sleep interval
end