Ruby Net::HTTP wrapper with retries in case of exceptions

safe_net_http.rb

require 'net/http'

module Utils
class Backoff
  RETR = 5
  def initialize(&blk)
    @retries = RETR
    @cmd = blk
  end
  def run!
    begin
      @cmd.call
    rescue StandardError => ex
      if @retries > 0
        puts "Caught #{ex.class}: #{ex.message} - Retrying..."
        backoff!
        @retries -= 1
        retry
      else
        puts "ERROR: Not responding after #{RETR} retries!  Giving up!"
        exit
      end
    end
  end

  private
  def backoff!
    nap = (2**@retries - 1) / 2
    puts "sleeping for #{nap} seconds"
    sleep nap
  end
end

module SafeNetHTTP
  def self.start(uri, opts, &blk)
    (Backoff.new do
      Net::HTTP.start(uri.host, uri.port, opts){ |handler| yield handler }
    end).run!
  end
end
end

test.rb

require 'net/http'
require 'uri'
require 'rufus-scheduler'

require_relative "safe_net_http"


include Utils

scheduler = Rufus::Scheduler.new

scheduler.in '3s' do
  uri = URI.parse("http://google.com/")
  resp = SafeNetHTTP.start(uri, use_ssl: false) do |http|
    http.request(Net::HTTP::Get.new(uri.path))
  end
  puts "got #{resp.code}"
  ## TODO: retry in case of resp.code 4xx, 5xx
end

scheduler.join