Add irs_process_scripts plugin to replace process control scripts used

[rails.git] / vendor / plugins / irs_process_scripts / lib / commands / process / reaper.rb

diff --git a/vendor/plugins/irs_process_scripts/lib/commands/process/reaper.rb b/vendor/plugins/irs_process_scripts/lib/commands/process/reaper.rb
new file mode 100644 (file)
index 0000000..95175d4
--- /dev/null
+++ b/vendor/plugins/irs_process_scripts/lib/commands/process/reaper.rb
@@ -0,0 +1,149 @@
+require 'optparse'
+require 'net/http'
+require 'uri'
+
+if RUBY_PLATFORM =~ /(:?mswin|mingw)/ then abort("Reaper is only for Unix") end
+
+class Killer
+  class << self
+    # Searches for all processes matching the given keywords, and then invokes
+    # a specific action on each of them. This is useful for (e.g.) reloading a
+    # set of processes:
+    #
+    #   Killer.process(:reload, "/tmp/pids", "dispatcher.*.pid")
+    def process(action, pid_path, pattern, keyword)
+      new(pid_path, pattern, keyword).process(action)
+    end
+
+    # Forces the (rails) application to reload by sending a +HUP+ signal to the
+    # process.
+    def reload(pid)
+      `kill -s HUP #{pid}`
+    end
+
+    # Force the (rails) application to restart by sending a +USR2+ signal to the
+    # process.
+    def restart(pid)
+      `kill -s USR2 #{pid}`
+    end
+
+    # Forces the (rails) application to gracefully terminate by sending a
+    # +TERM+ signal to the process.
+    def graceful(pid)
+      `kill -s TERM #{pid}`
+    end
+
+    # Forces the (rails) application to terminate immediately by sending a -9
+    # signal to the process.
+    def kill(pid)
+      `kill -9 #{pid}`
+    end
+
+    # Send a +USR1+ signal to the process.
+    def usr1(pid)
+      `kill -s USR1 #{pid}`
+    end
+  end
+
+  def initialize(pid_path, pattern, keyword=nil)
+    @pid_path, @pattern, @keyword = pid_path, pattern, keyword
+  end
+
+  def process(action)
+    pids = find_processes
+
+    if pids.empty?
+      warn "Couldn't find any pid file in '#{@pid_path}' matching '#{@pattern}'"
+      warn "(also looked for processes matching #{@keyword.inspect})" if @keyword
+    else
+      pids.each do |pid|
+        puts "#{action.capitalize}ing #{pid}"
+        self.class.send(action, pid)
+      end
+      
+      delete_pid_files if terminating?(action)
+    end      
+  end
+  
+  private
+    def terminating?(action)
+      [ "kill", "graceful" ].include?(action)
+    end
+  
+    def find_processes
+      files = pid_files
+      if files.empty?
+        find_processes_via_grep
+      else
+        files.collect { |pid_file| File.read(pid_file).to_i }
+      end
+    end
+
+    def find_processes_via_grep
+      lines = `ps axww -o 'pid command' | grep #{@keyword}`.split(/\n/).
+        reject { |line| line =~ /inq|ps axww|grep|spawn-fcgi|spawner|reaper/ }
+      lines.map { |line| line[/^\s*(\d+)/, 1].to_i }
+    end
+    
+    def delete_pid_files
+      pid_files.each { |pid_file| File.delete(pid_file) }
+    end
+    
+    def pid_files
+      Dir.glob(@pid_path + "/" + @pattern)
+    end
+end
+
+
+OPTIONS = {
+  :action     => "restart",
+  :pid_path   => File.expand_path(RAILS_ROOT + '/tmp/pids'),
+  :pattern    => "dispatch.[0-9]*.pid",
+  :dispatcher => File.expand_path("#{RAILS_ROOT}/public/dispatch.fcgi")
+}
+
+ARGV.options do |opts|
+  opts.banner = "Usage: reaper [options]"
+
+  opts.separator ""
+
+  opts.on <<-EOF
+  Description:
+    The reaper is used to restart, reload, gracefully exit, and forcefully exit processes
+    running a Rails Dispatcher (or any other process responding to the same signals). This
+    is commonly done when a new version of the application is available, so the existing
+    processes can be updated to use the latest code.
+
+    It uses pid files to work on the processes and by default assume them to be located
+    in RAILS_ROOT/tmp/pids. 
+
+    The reaper actions are:
+
+    * restart : Restarts the application by reloading both application and framework code
+    * reload  : Only reloads the application, but not the framework (like the development environment)
+    * graceful: Marks all of the processes for exit after the next request
+    * kill    : Forcefully exists all processes regardless of whether they're currently serving a request
+
+    Restart is the most common and default action.
+
+  Examples:
+    reaper                  # restarts the default dispatchers
+    reaper -a reload        # reload the default dispatchers
+    reaper -a kill -r *.pid # kill all processes that keep pids in tmp/pids
+  EOF
+
+  opts.on("  Options:")
+
+  opts.on("-a", "--action=name", "reload|graceful|kill (default: #{OPTIONS[:action]})", String)  { |v| OPTIONS[:action] = v }
+  opts.on("-p", "--pidpath=path", "default: #{OPTIONS[:pid_path]}", String)                      { |v| OPTIONS[:pid_path] = v }
+  opts.on("-r", "--pattern=pattern", "default: #{OPTIONS[:pattern]}", String)                    { |v| OPTIONS[:pattern] = v }
+  opts.on("-d", "--dispatcher=path", "DEPRECATED. default: #{OPTIONS[:dispatcher]}", String)     { |v| OPTIONS[:dispatcher] = v }
+
+  opts.separator ""
+
+  opts.on("-h", "--help", "Show this help message.") { puts opts; exit }
+
+  opts.parse!
+end
+
+Killer.process(OPTIONS[:action], OPTIONS[:pid_path], OPTIONS[:pattern], OPTIONS[:dispatcher])