Class: Penctl

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

Class Method Summary collapse

Class Method Details

.execute(server, cmd, tries_left = 5) ⇒ Object

Connects to pen’s control port and issues a command. It will wait a moment and 

try to contact the pen server again, when it could not be reached (raising an
exception when it gives up).

Raises:

  • (StandardError) 


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# File 'lib/penctl.rb', line 10

def self.execute( server, cmd, tries_left = 5 )
  raise StandardError.new("Error talking to pen, giving up.") unless tries_left > 0
  shell_cmd = "penctl #{server} #{cmd}"
  host, port = server.split ':'
  begin
    send_command( host, port, cmd )
  rescue Errno::ECONNRESET, Errno::EPIPE
    sleep 0.5
    return Penctl.execute( server, cmd, tries_left.pred)
  end
end

.get_set_attribute(pen, attribute, value = nil) ⇒ Object

Takes an attribute name along with a value and returns the value.



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# File 'lib/penctl.rb', line 70

def self.get_set_attribute(pen, attribute, value = nil)
  cmd   = attribute.to_s.chomp '='
  value = value.to_s.empty? ? '' : " #{value}"
  tidy_output(Penctl.execute(pen, "#{cmd}#{value}".chomp))
end

.parse_server_line(line) ⇒ Object

Takes a line of the output of penctl’s ‘servers’ command and turns it into

a hash with the keys :slot, :addr:, :port, :conn, :max, :hard, :sx, :rx



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# File 'lib/penctl.rb', line 49

def self.parse_server_line( line )
  keys = %w{ slot addr port conn max hard sx rx}
  hash = Hash[*("slot #{line}".split)]
  server = {}
  keys.each { |k| server[k.to_sym] = (k == "addr") ? hash[k] : hash[k].to_i  }
  return server
end

.send_command(host, port, cmd) ⇒ Object

Opens a socket, sends a command to pen and returns the result



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# File 'lib/penctl.rb', line 25

def self.send_command( host, port, cmd )
  socket = TCPSocket.open( host, port.to_i )
  socket.puts cmd
  result = []
  while line = socket.gets
    result << line.chomp
  end
  socket.close
  result
end

.set_boolean_attribute(pen, attribute, value) ⇒ Object

Takes an attribute name along with a boolean value and turns it into

a penctl command. Returns true on success, false on failure.



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# File 'lib/penctl.rb', line 61

def self.set_boolean_attribute(pen, attribute, value)
  cmd = attribute.to_s.chomp '='
  cmd = value ? cmd : "no " + cmd
  Penctl.execute(pen, cmd) == ["0"]
end

.update_server(server, slot, settings) ⇒ Object

Sends a penctl server command to update a server’s settings.



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# File 'lib/penctl.rb', line 39

def self.update_server( server, slot, settings )
  cmd = settings.to_a.sort_by{ |k,v| k.to_s }.flatten.join(' ')
  Penctl.execute( server, "server #{slot} #{cmd}" )
end