add scale command

lib/foreman/cli.rb

@@ -1,4 +1,5 @@
 require "foreman"
+require "foreman/configuration"
 require "foreman/engine"
 require "foreman/export"
 require "thor"
@@ -12,9 +13,9 @@ class Foreman::CLI < Thor
     Foreman::Engine.new(procfile).start
   end
 
-  desc "export NAME [PROCFILE] [FORMAT]", "Export the app described in PROCFILE as NAME to another FORMAT"
+  desc "export APP [PROCFILE] [FORMAT]", "Export the app described in PROCFILE as APP to another FORMAT"
 
-  def export(name, procfile="Procfile", format="upstart")
+  def export(app, procfile="Procfile", format="upstart")
     error "#{procfile} does not exist." unless File.exist?(procfile)
 
     formatter = case format
@@ -22,7 +23,26 @@ class Foreman::CLI < Thor
       else error "Unknown export format: #{format}"
     end
 
-    formatter.new(Foreman::Engine.new(procfile)).export(name)
+    formatter.new(Foreman::Engine.new(procfile)).export(app)
+  end
+
+  desc "scale APP PROCESS AMOUNT", "Change the concurrency of a given process type"
+
+  def scale(app, process, amount)
+    config = Foreman::Configuration.new(app)
+
+    amount = amount.to_i
+    old_amount = config.processes[process]
+
+    config.scale(process, amount)
+
+    if (old_amount < amount)
+      ((old_amount+1)..amount).each { |num| system "start #{app}-#{process} NUM=#{num}" }
+    elsif (amount < old_amount)
+      ((amount+1)..old_amount).each { |num| system "stop #{app}-#{process} NUM=#{num}" }
+    end
+
+    config.write
   end
 
 private ######################################################################

lib/foreman/configuration.rb

@@ -0,0 +1,44 @@
+require "foreman"
+
+class Foreman::Configuration
+
+  attr_reader :app
+  attr_reader :processes
+
+  def initialize(app)
+    @app = app
+    @processes = {}
+    read_initial_config
+  end
+
+  def scale(process, amount)
+    processes[process] = amount.to_i
+  end
+
+  def write
+    write_file "/etc/foreman/#{app}.conf", <<-UPSTART_CONFIG
+#{app}_processes="#{processes.keys.join(' ')}"
+#{processes.keys.map { |k| "#{app}_#{k}=\"#{processes[k]}\"" }.join("\n")}
+    UPSTART_CONFIG
+  end
+
+private ######################################################################
+
+  def read_initial_config
+    config = File.read("/etc/foreman/#{app}.conf").split("\n").inject({}) do |accum, line|
+      key, value = line.match(/^(.+?)\s*=\s*"(.+?)"\s*$/).captures
+      #accum.update(parts(1) => parts(2))
+      accum.update(key => value)
+    end
+    config["#{app}_processes"].split(" ").each do |process|
+      scale(process, config["#{app}_#{process}"])
+    end
+  end
+
+  def write_file(filename, contents)
+    File.open(filename, "w") do |file|
+      file.puts contents
+    end
+  end
+
+end

lib/foreman/export/upstart.rb

@@ -1,3 +1,4 @@
+require "foreman/configuration"
 require "foreman/export"
 
 class Foreman::Export::Upstart
@@ -8,31 +9,33 @@ class Foreman::Export::Upstart
     @engine = engine
   end
 
-  def export(name)
+  def export(app)
     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
+    config = Foreman::Configuration.new(app)
 
-    write_file "/etc/init/#{name}.conf", <<-UPSTART_MASTER
+    engine.processes.each do |name, process|
+      config.scale(name, 1)
+    end
+    config.write
+
+    write_file "/etc/init/#{app}.conf", <<-UPSTART_MASTER
 pre-start script
 
 bash << "EOF"
-  mkdir -p /var/log/#{name}
+  mkdir -p /var/log/#{app}
 
-  if [ -f /etc/foreman/#{name}.conf ]; then
-    source /etc/foreman/#{name}.conf
+  if [ -f /etc/foreman/#{app}.conf ]; then
+    source /etc/foreman/#{app}.conf
   fi
 
-  for process in $( echo "$#{name}_processes" ); do
-    process_count_config="#{name}_$process"
+  for process in $( echo "$#{app}_processes" ); do
+    process_count_config="#{app}_$process"
     process_count=${!process_count_config}
 
     for ((i=1; i<=${process_count:=1}; i+=1)); do
-      start #{name}-$process NUM=$i
+      start #{app}-$process NUM=$i
     done
   done
 EOF
@@ -41,18 +44,18 @@ end script
     UPSTART_MASTER
 
     engine.processes.values.each do |process|
-      write_file "/etc/init/#{name}-#{process.name}.conf", <<-UPSTART_CHILD
+      write_file "/etc/init/#{app}-#{process.name}.conf", <<-UPSTART_CHILD
 instance $NUM
-stop on stopping #{name}
+stop on stopping #{app}
 respawn
 
 chdir #{engine.directory}
-exec #{process.command} >>/var/log/#{name}/#{process.name}.log 2>&1
+exec #{process.command} >>/var/log/#{app}/#{process.name}.log 2>&1
       UPSTART_CHILD
     end
   end
 
-private
+private ######################################################################
 
   def write_file(filename, contents)
     File.open(filename, "w") do |file|