initial commit

bin/foreman

@@ -0,0 +1,7 @@
+#!/usr/bin/env ruby
+
+$:.unshift File.expand_path("../../lib", __FILE__)
+
+require "foreman/cli"
+
+Foreman::CLI.start

example/Procfile

@@ -0,0 +1,3 @@
+neverdie ./never_die
+diealot  ./die_alot
+error    ./error

example/die_alot

@@ -0,0 +1,4 @@
+#!/usr/bin/env ruby
+
+sleep 2
+exit 0

example/error

@@ -0,0 +1,4 @@
+#!/usr/bin/env ruby
+
+sleep 10
+raise "Dying"

example/never_die

@@ -0,0 +1,5 @@
+#!/usr/bin/env ruby
+
+while true
+  sleep 5
+end

lib/foreman.rb

@@ -0,0 +1,6 @@
+module Foreman
+
+  VERSION = "0.0.1"
+
+end
+

lib/foreman/cli.rb

@@ -0,0 +1,35 @@
+require "foreman"
+require "foreman/engine"
+require "foreman/export"
+require "thor"
+
+class Foreman::CLI < Thor
+
+  desc "start [PROCFILE]", "Run the app described in PROCFILE"
+
+  def start(procfile="Procfile")
+    error "#{procfile} does not exist." unless File.exist?(procfile)
+    Foreman::Engine.new(procfile).start
+  end
+
+  desc "export NAME [PROCFILE] [FORMAT]", "Export the app described in PROCFILE as NAME to another FORMAT"
+
+  def export(name, procfile="Procfile", format="upstart")
+    error "#{procfile} does not exist." unless File.exist?(procfile)
+
+    formatter = case format
+      when "upstart" then Foreman::Export::Upstart
+      else error "Unknown export format: #{format}"
+    end
+
+    formatter.new(Foreman::Engine.new(procfile)).export(name)
+  end
+
+private ######################################################################
+
+  def error(message)
+    puts "ERROR: #{message}"
+    exit 1
+  end
+
+end

lib/foreman/engine.rb

@@ -0,0 +1,87 @@
+require "foreman"
+require "foreman/process"
+
+class Foreman::Engine
+
+  attr_reader :procfile
+  attr_reader :directory
+
+  def initialize(procfile)
+    @procfile  = File.read(procfile)
+    @directory = File.expand_path(File.dirname(procfile))
+  end
+
+  def processes
+    @processes ||= begin
+      procfile.split("\n").inject({}) do |hash, line|
+        next if line.strip == ""
+        process = Foreman::Process.new(*line.split(" ", 2))
+        hash.update(process.name => process)
+      end
+    end
+  end
+
+  def start
+    proctitle "ruby: foreman master"
+
+    processes.each do |name, process|
+      fork process
+    end
+
+    trap("TERM") { kill_and_exit("TERM") }
+    trap("INT")  { kill_and_exit("INT")  }
+    trap("INFO") { print_info }
+
+    while true
+      pid, status = Process.wait2
+      process = running_processes.delete(pid)
+      info "exited with code #{status}", process
+      fork process
+    end
+  end
+
+private ######################################################################
+
+  def fork(process)
+    pid = Process.fork do
+      proctitle "ruby: foreman #{process.name}"
+
+      Dir.chdir directory do
+        system process.command
+        exit $?.exitstatus || 255
+      end
+    end
+
+    info "started with pid #{pid}", process
+    running_processes[pid] = process
+  end
+
+  def kill_and_exit(signal="TERM")
+    info "termination requested"
+    running_processes.each do |pid, process|
+      info "killing pid #{pid}", process
+      Process.kill(signal, pid)
+    end
+    exit 0
+  end
+
+  def info(message, process=nil)
+    puts "[foreman] [#{Time.now.utc}] [#{process ? process.name : "system"}] #{message}"
+  end
+
+  def print_info
+    info "currently running processes:"
+    running_processes.each do |pid, process|
+      info "pid #{pid}", process
+    end
+  end
+
+  def running_processes
+    @running_processes ||= {}
+  end
+
+  def proctitle(title)
+    $0 = title
+  end
+
+end

lib/foreman/export.rb

@@ -0,0 +1,6 @@
+require "foreman"
+
+module Foreman::Export
+end
+
+require "foreman/export/upstart"

lib/foreman/export/upstart.rb

@@ -0,0 +1,63 @@
+require "foreman/export"
+
+class Foreman::Export::Upstart
+
+  attr_reader :engine
+
+  def initialize(engine)
+    @engine = engine
+  end
+
+  def export(name)
+    FileUtils.mkdir_p "/etc/foreman"
+    FileUtils.mkdir_p "/etc/init"
+
+    write_file "/etc/foreman/#{name}.conf", <<-UPSTART_CONFIG
+#{name}_processes="#{engine.processes.keys.join(' ')}"
+#{engine.processes.keys.map { |k| "#{name}_#{k}=\"1\"" }.join("\n")}
+    UPSTART_CONFIG
+
+    write_file "/etc/init/#{name}.conf", <<-UPSTART_MASTER
+pre-start script
+
+bash << "EOF"
+  mkdir -p /var/log/#{name}
+
+  if [ -f /etc/foreman/#{name}.conf ]; then
+    source /etc/foreman/#{name}.conf
+  fi
+
+  for process in $( echo "$#{name}_processes" ); do
+    process_count_config="#{name}_$process"
+    process_count=${!process_count_config}
+
+    for ((i=1; i<=${process_count:=1}; i+=1)); do
+      start #{name}-$process NUM=$i
+    done
+  done
+EOF
+
+end script
+    UPSTART_MASTER
+
+    engine.processes.values.each do |process|
+      write_file "/etc/init/#{name}-#{process.name}.conf", <<-UPSTART_CHILD
+instance $NUM
+stop on stopping #{name}
+respawn
+
+chdir #{engine.directory}
+exec #{process.command} 2>&1 > /var/log/#{name}/#{process.name}.log
+      UPSTART_CHILD
+    end
+  end
+
+private
+
+  def write_file(filename, contents)
+    File.open(filename, "w") do |file|
+      file.puts contents
+    end
+  end
+
+end

lib/foreman/process.rb

@@ -0,0 +1,13 @@
+require "foreman"
+
+class Foreman::Process
+
+  attr_reader :name
+  attr_reader :command
+
+  def initialize(name, command)
+    @name    = name
+    @command = command
+  end
+
+end