Module: Vagrant::Util::IsPortOpen

Included in:
Action::Builtin::HandleForwardedPortCollisions
Defined in:
lib/vagrant/util/is_port_open.rb

Overview

Contains the method #is_port_open? to check if a port is open (listening) or closed (not in use). This method isn't completely fool-proof, but it works enough of the time to be useful.

Instance Method Summary collapse

Instance Method Details

#is_port_open?(host, port) ⇒ Boolean

Checks if a port is open (listening) on a given host and port.

Parameters:

  • host (String)

    Hostname or IP address.

  • port (Integer)

    Port to check.

Returns:

  • (Boolean)

    true if the port is open (listening), false otherwise.



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# File 'lib/vagrant/util/is_port_open.rb', line 16

def is_port_open?(host, port)
  # We wrap this in a timeout because once in awhile the TCPSocket
  # _will_ hang, but this signals that the port is closed.
  Timeout.timeout(1) do
    # Attempt to make a connection
    s = TCPSocket.new(host, port)

    # A connection was made! Properly clean up the socket, not caring
    # at all if any exception is raised, because we already know the
    # result.
    s.close rescue nil

    # The port is open if we reached this point, since we were able
    # to connect.
    return true
  end
rescue Timeout::Error, Errno::ECONNREFUSED, Errno::EHOSTUNREACH, Errno::ENETUNREACH
  # Any of the above exceptions signal that the port is closed.
  return false
end