Add -w option for repeated runs

README.md

@@ -1,5 +1,6 @@
 [![Build Status](https://travis-ci.org/hammady/scaltainer.svg?branch=master)](https://travis-ci.org/hammady/scaltainer)
 [![Coverage Status](https://coveralls.io/repos/github/hammady/scaltainer/badge.svg?service=github&branch=master)](https://coveralls.io/github/hammady/scaltainer?branch=master)
+[![Gem Version](https://badge.fury.io/rb/scaltainer.svg)](https://badge.fury.io/rb/scaltainer)
 
 # Scaltainer
 
@@ -41,7 +42,12 @@ Example:
 
     scaltainer -f /path/to/configuration/file.yml --state-file /path/to/different/state/file.yml
 
-Typically, the above command should be put inside a cronjob that is triggered every minute or so.
+Typically one would want to repeatedly call scaltainer every minute or so. To do this
+specify the wait time between repetitions using the `-w` parameter in seconds:
+
+    scaltainer -w 60
+
+This will repeatedly call scaltainer every 60 seconds, sleeping in between.
 
 ## Configuration
 

exe/scaltainer

@@ -3,8 +3,8 @@
 require 'scaltainer'
 
 begin
-  configfile, statefile, logger = Scaltainer::Command.parse ARGV
-  Scaltainer::Runner.new configfile, statefile, logger
+  configfile, statefile, logger, wait = Scaltainer::Command.parse ARGV
+  Scaltainer::Runner.new configfile, statefile, logger, wait
 rescue => e
   $stderr.puts e.message
   $stderr.puts e.backtrace

lib/scaltainer/command.rb

@@ -4,7 +4,7 @@
 module Scaltainer
   class Command
     def self.parse(args)
-      configfile, statefile = 'scaltainer.yml', nil
+      configfile, statefile, wait = 'scaltainer.yml', nil, 0
       OptionParser.new do |opts|
         opts.banner = "Usage: scaltainer [options]"
         opts.on("-f", "--conf-file FILE", "Specify configuration file (default: scaltainer.yml)") do |file|
@@ -13,6 +13,9 @@ def self.parse(args)
         opts.on("--state-file FILE", "Specify state file (default: <conf-file>.state)") do |file|
           statefile = file
         end
+        opts.on("-w", "--wait SECONDS", "Specify wait time between repeated calls, 0 for no repetition (default: 0)") do |w|
+          wait = w.to_i
+        end
         opts.on_tail("-h", "--help", "Show this message") do
           puts opts
           puts "\nEnvironment variables: \n"
@@ -35,7 +38,7 @@ def self.parse(args)
       logger = Logger.new(STDOUT)
       logger.level = %w(debug info warn error fatal unknown).find_index((ENV['LOG_LEVEL'] || '').downcase) || 1
 
-      return configfile, statefile, logger
+      return configfile, statefile, logger, wait
     end
 
     private

lib/scaltainer/runner.rb

@@ -2,7 +2,7 @@
 
 module Scaltainer
   class Runner
-    def initialize(configfile, statefile, logger)
+    def initialize(configfile, statefile, logger, wait)
       @logger = logger
       @default_service_config = {
         "min" => 0,
@@ -16,14 +16,24 @@ def initialize(configfile, statefile, logger)
       Docker.logger = @logger
       state = get_state(statefile) || {}
       endpoint = config["endpoint"]
-      service_prefix = config["stack_name"]
-      iterate_services config["web_services"], service_prefix, ServiceTypeWeb.new(endpoint), state
-      iterate_services config["worker_services"], service_prefix, ServiceTypeWorker.new(endpoint), state
-      save_state statefile, state
+      service_type_web = ServiceTypeWeb.new(endpoint)
+      service_type_worker = ServiceTypeWorker.new(endpoint)
+      loop do
+        run config, state, service_type_web, service_type_worker
+        save_state statefile, state
+        sleep wait
+        break if wait == 0
+      end
     end
 
     private
 
+    def run(config, state, service_type_web, service_type_worker)
+      service_prefix = config["stack_name"]
+      iterate_services config["web_services"], service_prefix, service_type_web, state
+      iterate_services config["worker_services"], service_prefix, service_type_worker, state
+    end
+
     def get_state(statefile)
       YAML.load_file statefile if File.exists? statefile
     end

lib/scaltainer/version.rb

@@ -1,3 +1,3 @@
 module Scaltainer
-  VERSION = "0.1.3"
+  VERSION = "0.1.4"
 end