initial commit

bin/retry

@@ -0,0 +1,7 @@
+#!/usr/bin/env ruby
+
+require 'rubygems'
+
+require File.expand_path("../../lib/retryit.rb", __FILE__)
+
+RetryIt.new.run(ARGV)

lib/retryit.rb

@@ -0,0 +1,80 @@
+require 'optparse'
+
+
+class RetryIt
+
+  attr_accessor :max_retries, :min_sleep, :max_sleep, :constant_sleep
+
+  def initialize()
+    @max_tries = 10
+    @min_sleep = 0.3
+    @max_sleep = 60.0
+    @constant_sleep = nil
+  end
+
+  def load_options(args)
+    return if args.size < 1
+
+    optparser = OptionParser.new do |opts|
+      opts.banner = "Usage: retry [options] -e execute command"
+
+      opts.on("-t#", "--tries=#", Integer, "Set max retries: Default 10") do |v|
+        @max_tries = v
+      end
+
+      opts.on("-s#", "--sleep=secs", Float, "Constant sleep amount (seconds)") do |v|
+        @constant_sleep = v
+      end
+
+      opts.on("--min=secs", Float, "Exponenetial Backoff: minimum sleep amount (seconds): Default 0.3") do |v|
+        @min_sleep = v
+      end
+
+      opts.on("--max=secs", Float, "Exponenetial Backoff: maximum sleep amount (seconds): Default 60") do |v|
+        @max_sleep = v
+      end
+
+    end
+
+    optparser.parse(*args)
+  end
+
+  def sleep_amount(attempts)
+    @constant_sleep || [@min_sleep * (2 ** (attempts - 1)), @max_sleep].min
+  end
+
+  def log_out(message)
+    STDERR.puts(message)
+  end
+
+  def run(args)
+
+    idx = args.find_index("-e")
+    if !idx.nil?
+      load_options(args[0...idx])
+      args = args[(idx+1)..-1]
+    end
+
+    raise "max_tries must be greater than 0" unless @max_tries > 0
+    raise "minimum sleep cannot be greater than maximum sleep" unless @max_sleep >= @min_sleep
+    raise "unknown execute command" unless args.size > 0
+
+    process = nil
+    attempts = 0
+    success = false
+    while (success == false && attempts <= @max_tries)
+      if (attempts > 0)
+        sleep_time = sleep_amount(attempts)
+        log_out("Before retry ##{attempts}: sleeping #{sleep_time} seconds")
+        sleep sleep_time
+      end
+      success = system(args[0], *args[1..-1])
+      process = $?
+      attempts += 1
+    end
+
+    log_out("Command Failed: #{args[0]}") if success.nil?
+    exit process.exitstatus
+  end
+
+end

retryit.gemspec

@@ -0,0 +1,15 @@
+# -*- encoding: utf-8 -*-
+
+Gem::Specification.new do |s|
+  s.name        = 'retryit'
+  s.version     = '0.1.0'
+  s.summary     = "retry any command line"
+  s.description = "General purpose retry cli program for anything"
+  s.authors     = ["Neville Kadwa"]
+  s.email       = ["neville@kadwa.com"]
+  s.files       = Dir['lib/**/*.rb'] + Dir['bin/*'] + Dir['[A-Z]*']
+  s.test_files  = Dir['test/**/*']
+  s.executables = Dir['bin/**/*'].map{|f| File.basename(f)}
+  s.homepage    = 'http://github.com/kadwanev/retry'
+  s.licenses    = ['Apache-2.0']
+end