Class: Hayabusa::Fcgi

Inherits:
Object
  • Object
show all
Defined in:
lib/hayabusa_fcgi.rb

Overview

This class is used for FCGI-sessions. It normally starts a Hayabusa-host-process which this (and other) FCGI-processes will proxy requests to. The host-process will automatically kill itself when no more FCGI-sessions are connected to emulate normal FCGI behaviour.

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Fcgi

Returns a new instance of Fcgi.



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# File 'lib/hayabusa_fcgi.rb', line 5

def initialize
  #Spawn CGI-variable to emulate FCGI part.
  @cgi_tools = Hayabusa::Cgi_tools.new
  
  #We cant define the Hayabusa-server untuil we receive the first headers, so wait for the first request.
  @hayabusa = nil
  @hayabusa_fcgi_conf_path = nil
  @fcgi_proxy = nil
  @debug = false
end

Instance Method Details

#conf_path ⇒ Object 



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# File 'lib/hayabusa_fcgi.rb', line 16

def conf_path
  #Parse the configuration-header and generate Hayabusa-config-hash.
  if @cgi.env["HAYABUSA_FCGI_CONFIG"].to_s.length > 0
    return @cgi.env["HAYABUSA_FCGI_CONFIG"]
  elsif @cgi.env["HTTP_HAYABUSA_FCGI_CONFIG"].to_s.length > 0
    return @cgi.env["HTTP_HAYABUSA_FCGI_CONFIG"]
  else
    raise "No HTTP_HAYABUSA_FCGI_CONFIG-header was given or HAYABUSA_FCGI_CONFIG environment variable."
  end
end

#evaluate_mode ⇒ Object

Evaluates if a new host-process should be started or we should proxy calls to an existing one.



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# File 'lib/hayabusa_fcgi.rb', line 28

def evaluate_mode
  #If this is a FCGI-proxy-instance then the HTTP-connection should be checked if it is working.
  if @fcgi_proxy
    if !@fcgi_proxy[:http].socket_working?
      @fcgi_proxy = nil
    end
  end
  
  #Skip the actual check if Hayabusa is spawned or this is a working FCGI-proxy-instance.
  return nil if @hayabusa or @fcgi_proxy
  
  @hayabusa_fcgi_conf_path = conf_path
  require @hayabusa_fcgi_conf_path
  raise "No 'Hayabusa::FCGI_CONF'-constant was spawned by '#{@cgi.env["HTTP_HAYABUSA_FCGI_CONFIG"]}'." if !Hayabusa.const_defined?(:FCGI_CONF)
  conf = Hayabusa::FCGI_CONF
  
  hayabusa_conf = Hayabusa::FCGI_CONF[:hayabusa]
  hayabusa_conf.merge!(
    :cmdline => false,
    :mailing_timeout => 1, #Since FCGI might terminate at any time, try to send out mails almost instantly in the background.
    :port => 0 #Ruby picks random port and we get the actual port after starting the appserver.
  )
  
  #Figure out if this should be a host-FCGI-process or a proxy-FCGI-process.
  fcgi_config_fp = "#{Knj::Os.tmpdir}/hayabusa_fcgi_#{hayabusa_conf[:title]}_fcgi.conf"
  FileUtils.touch(fcgi_config_fp) if !File.exists?(fcgi_config_fp)
  
  File.open(fcgi_config_fp) do |fp|
    fp.flock(File::LOCK_EX)
    
    fcgi_config_cont = File.read(fcgi_config_fp) rescue ""
    if !fcgi_config_cont.empty?
      #Seems like an instance is already running - check PID to be sure.
      fcgi_config = Marshal.load(File.read(fcgi_config_fp))
      pid = fcgi_config[:pid]
      
      if Knj::Unix_proc.pid_running?(pid)
        #Set this instance to run in proxy-mode.
        begin
          @fcgi_proxy = fcgi_config
          Knj.gem_require(:Http2)
          
          begin
            @fcgi_proxy[:http] = Http2.new(:host => "localhost", :port => @fcgi_proxy[:port].to_i, :raise_errors => false)
          rescue Errno::ECONNREFUSED
            #The host-process has properly closed - evaluate mode again.
            raise Errno::EAGAIN
          end
          
          if hayabusa_conf[:debug]
            @fcgi_proxy[:fp_log] = File.open("/tmp/hayabusa_#{hayabusa_conf[:title]}_#{Process.pid}.log", "w")
            @fcgi_proxy[:fp_log].sync = true
          end
        rescue
          @fcgi_proxy = nil
          raise
        end
      end
    end
    
    #No instance is already running - start new Hayabusa-instance in both CGI- and socket-mode and write that to the config-file so other instances will register this as the main host-instance.
    if !@fcgi_proxy
      #Spawn sub-process that actually runs the Hayabusa-server.
      require "open3"
      cmd = "#{Knj::Os.executed_executable} #{File.realpath(File.dirname(__FILE__))}/../bin/hayabusa_fcgi_server.rb --conf_path=#{Knj::Strings.unixsafe(@hayabusa_fcgi_conf_path)} --fcgi_data_path=#{Knj::Strings.unixsafe(fcgi_config_fp)}"
      
      #Only used to identify the running FCGI-server host-processes with 'ps aux'.
      cmd << " --title=#{Knj::Strings.unixsafe(hayabusa_conf[:title])}" if hayabusa_conf[:title]
      
      $stderr.puts("Executing command to start FCGI-server: #{cmd}")
      
      if RUBY_ENGINE == "jruby"
        pid, io_out, io_in, io_err = IO.popen4(cmd)
      else
        io_out, io_in, io_err, wait_thr = Open3.popen3(cmd)
        pid = wait_thr.pid
      end
      
      #Get data that should contain PID and port.
      read = io_in.gets
      
      if !read and !Knj::Unix_proc.pid_running?(pid)
        err_str = io_err.read
        raise "An error occurred while trying to start host-process: #{err_str}" if !err_str.to_s.strip.empty?
        raise "Host-process died unexpectedly with no read, PID '#{pid}' and using cmd '#{cmd}'." 
        raise "Host-process didnt return required data."
      end
      
      #Parse data from the host-process (port and PID).
      begin
        data = Marshal.load(Base64.strict_decode64(read.strip))
      rescue
        raise "Invalid data given from host-process: '#{read}'."
      end
      
      
      #Detach the process where the HTTP-server runs from this process.
      Process.detach(data[:pid])
      
      #Write the data about the new HTTP-server in the config-file and re-evaluate mode. The host-process should not write the file itself, since this process has a lock on that file, and another process might try to start another host-process while writing the file from the host-process, which is not desired.
      File.open(fcgi_config_fp, "w") do |fp|
        fp.write(Marshal.dump(
          :pid => data[:pid],
          :port => data[:port]
        ))
        
        #Started host-process - evaluate mode again and proxy request to the host-process.
        raise Errno::EAGAIN
      end
    end
  end
end

#fcgi_loop ⇒ Object

Handels the requests comming from the FCGI-object in a loop.



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# File 'lib/hayabusa_fcgi.rb', line 142

def fcgi_loop
  $stderr.puts "[hayabusa] Starting FCGI." if @debug
  
  begin
    FCGI.each do |cgi|
      begin
        #Set 'cgi'-variable for CGI-tools.
        @cgi_tools.cgi = cgi
        @cgi = cgi
        
        #Evaluate the mode of this instance.
        begin
          self.evaluate_mode
        rescue Errno::EAGAIN
          retry
        end
        
        #Ensure the same FCGI-process isnt active for more than one website.
        raise "Expected 'HTTP_HAYABUSA_FCGI_CONFIG' to be '#{@hayabusa_fcgi_conf_path}' but it wasnt: '#{conf_path}' #{@cgi.env}" if @hayabusa_fcgi_conf_path != conf_path
        
        #Proxy request to the host-FCGI-process.
        raise "No proxy spawned." unless @fcgi_proxy
        $stderr.puts "[hayabusa] Proxying request." if @debug
        @cgi_tools.proxy_request_to(:cgi => cgi, :http => @fcgi_proxy[:http], :fp_log => @fcgi_proxy[:fp_log])
      rescue Errno::ECONNABORTED, Errno::ECONNREFUSED, Errno::ECONNRESET => e
        $stderr.puts "[hayabusa] Connection to server was interrupted - trying again: <#{e.class.name}> #{e.message}"
        @fcgi_proxy = nil #Force re-evaluate if this process should be host or proxy.
        retry
      rescue Exception => e
        @cgi.out.print "Content-Type: text/html\r\n"
        @cgi.out.print "\r\n"
        @cgi.out.print Knj::Errors.error_str(e, :html => true)
        
        if @hayabusa
          @hayabusa.log_puts e.inspect
          @hayabusa.log_puts e.backtrace
        else
          STDERR.puts e.inspect
          STDERR.puts e.backtrace
        end
      ensure
        @cgi.finish
        @cgi = nil
        @cgi_tools.cgi = nil
      end
    end
  ensure
    $stderr.puts "[hayabusa] FCGI-loop stopped."
    @hayabusa.stop if @hayabusa
  end
end