Class: Merb::Server

Inherits:
Object show all
Defined in:
lib/merb-core/server.rb

Overview

Server encapsulates the management of Merb daemons.

Class Method Summary collapse

Class Method Details

.alive?(port) ⇒ Boolean

Parameters

port<~to_s>

The port to check for Merb instances on.

Returns

Boolean

True if Merb is running on the specified port.

Returns:

  • (Boolean) 


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# File 'lib/merb-core/server.rb', line 53

def alive?(port)
  f = "#{Merb.log_path}" / "merb.#{port}.pid"
  pid = IO.read(f).chomp.to_i
  Process.kill(0, pid)
  true
rescue
  false
end

.change_privilege(user, group = user) ⇒ Object

Change privileges of the process to the specified user and group.

Parameters

user<String>

The user who should own the server process.

group<String>

The group who should own the server process.

Alternatives

If group is left out, the user will be used as the group.



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# File 'lib/merb-core/server.rb', line 165

def change_privilege(user, group=user)
  
  puts "Changing privileges to #{user}:#{group}"
  
  uid, gid = Process.euid, Process.egid
  target_uid = Etc.getpwnam(user).uid
  target_gid = Etc.getgrnam(group).gid

  if uid != target_uid || gid != target_gid
    # Change process ownership
    Process.initgroups(user, target_gid)
    Process::GID.change_privilege(target_gid)
    Process::UID.change_privilege(target_uid)
  end
rescue Errno::EPERM => e
  puts "Couldn't change user and group to #{user}:#{group}: #{e}"
end

.daemonize(port) ⇒ Object

Parameters

port<~to_s>

The port of the Merb process to daemonize.



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# File 'lib/merb-core/server.rb', line 96

def daemonize(port)
  fork do
    Process.setsid
    exit if fork
    File.umask 0000
    STDIN.reopen "/dev/null"
    STDOUT.reopen "/dev/null", "a"
    STDERR.reopen STDOUT
    trap("TERM") { exit }
    Dir.chdir Merb::Config[:merb_root]
    at_exit { remove_pid_file(port) }
    Merb::Config[:port] = port
    if Merb::Config[:user]
      if Merb::Config[:group]
        change_privilege(Merb::Config[:user], Merb::Config[:group])
      else
        change_privilege(Merb::Config[:user])
      end    
    end  
    BootLoader.run
    Merb.adapter.start(Merb::Config.to_hash)
  end
end

.kill(port, sig = 9) ⇒ Object

Parameters

port<~to_s>

The port of the Merb process to kill.

sig<~to_s>

The signal to send to the process. Defaults to 9.

Alternatives

If you pass “all” as the port, the signal will be sent to all Merb processes.



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# File 'lib/merb-core/server.rb', line 69

def kill(port, sig=9)
  Merb::BootLoader::BuildFramework.run
  begin
    Dir[Merb.log_path/ "merb.#{port == 'all' ? '*' : port }.pid"].each do |f|
      pid = IO.read(f).chomp.to_i
      begin
        Process.kill(sig, pid)
        FileUtils.rm(f) if File.exist?(f)
        puts "killed PID #{pid} with signal #{sig}"
      rescue Errno::EINVAL
        puts "Failed to kill PID #{pid}: '#{sig}' is an invalid or unsupported signal number."
      rescue Errno::EPERM
        puts "Failed to kill PID #{pid}: Insufficient permissions."
      rescue Errno::ESRCH
        puts "Failed to kill PID #{pid}: Process is deceased or zombie."
        FileUtils.rm f
      rescue Exception => e
        puts "Failed to kill PID #{pid}: #{e.message}"
      end
    end
  ensure  
    exit
  end
end

.remove_pid_file(port) ⇒ Object

Removes a PID file from the filesystem.

Parameters

port<~to_s>

The port of the Merb process to whom the the PID file belongs to.

Alternatives

If Merb::Config has been specified, that will be used instead of the port based PID file.



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# File 'lib/merb-core/server.rb', line 129

def remove_pid_file(port)
  if Merb::Config[:pid_file]
    pidfile = Merb::Config[:pid_file]
  else
    pidfile = Merb.log_path / "merb.#{port}.pid"
  end
  FileUtils.rm(pidfile) if File.exist?(pidfile)
end

.start(port, cluster = nil) ⇒ Object

Start a Merb server, in either foreground, daemonized or cluster mode.

Parameters

port<~to_i>

The port to which the first server instance should bind to. Subsequent server instances bind to the immediately following ports.

cluster<~to_i>

Number of servers to run in a cluster.

Alternatives

If cluster is left out, then one process will be started. This process will be daemonized if Merb::Config is true.



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# File 'lib/merb-core/server.rb', line 20

def start(port, cluster=nil)
  @port = port
  @cluster = cluster
  if @cluster
    @port.to_i.upto(@port.to_i + @cluster.to_i-1) do |port|
      unless alive?(port)
        remove_pid_file(port)
        puts "Starting merb server on port: #{port}"
        daemonize(port)
      else
        raise "Merb is already running on port: #{port}"
      end
    end   
  elsif Merb::Config[:daemonize]
    unless alive?(@port)  
      remove_pid_file(@port)
      daemonize(@port)
    else
      raise "Merb is already running on port: #{port}"
    end
  else
    trap('TERM') { exit }
    BootLoader.run
    Merb.adapter.start(Merb::Config.to_hash)
  end
end

.store_pid(port) ⇒ Object

Stores a PID file on the filesystem.

Parameters

port<~to_s>

The port of the Merb process to whom the the PID file belongs to.

Alternatives

If Merb::Config has been specified, that will be used instead of the port based PID file.



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# File 'lib/merb-core/server.rb', line 147

def store_pid(port)
  FileUtils.mkdir_p(Merb.log_path) unless File.directory?(Merb.log_path)
  if Merb::Config[:pid_file]
    pidfile = Merb::Config[:pid_file]
  else
    pidfile = Merb.log_path / "merb.#{port}.pid"
  end
  File.open(pidfile, 'w'){ |f| f.write("#{Process.pid}") }
end