Class: KnifeBastion::ClientProxy

Inherits:
BasicObject
Defined in:
lib/knife-bastion/client_proxy.rb

Overview

Simple class, that delegates all the calls to the base client object. The latter is overwritten to first configure SOCKS proxy, and if connection fails - show warning about the bastion setup.

Constant Summary collapse

NETWORK_ERRORS = 
[
  ::SocketError,
  ::Errno::ETIMEDOUT,
  ::Errno::ECONNRESET,
  ::Errno::ECONNREFUSED,
  ::Timeout::Error,
  ::OpenSSL::SSL::SSLError,
  defined?(::Berkshelf::ChefConnectionError) ? ::Berkshelf::ChefConnectionError : nil,
].compact.freeze

Instance Method Summary collapse

Constructor Details

#initialize(client, options = {}) ⇒ ClientProxy

Initializes an instance of the generic client proxy which sends all the

network traffic through the SOCKS proxy.

Parameters:

  • client (Object) —

    the client object which communicates with the server over the network.

  • options (Hash) (defaults to: {}) —

    the configuration of the client proxy.

Options Hash (options):

  • :local_port (Integer) — default: 4443 —

    The local port of the SOCKS proxy.

  • :error_handler (Proc) —

    network errors handler. By default it prints out a message which explains that the error may occur becase the bastion proxy has not been started.



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# File 'lib/knife-bastion/client_proxy.rb', line 31

def initialize(client, options = {})
  @client = client

  @local_port = options[:local_port] || 4443

  server_type = ::HighLine.color("#{options[:server_type]} ", [:bold, :cyan]) if options[:server_type]
  @network_errors_handler = options[:error_handler] || -> (_) {
    ::Kernel.puts
    ::Kernel.puts '-' * 80
    ::Kernel.puts ::HighLine.color("WARNING:", [:bold, :red]) + " Failed to contact #{server_type}server!"
    ::Kernel.puts "You might need to start bastion connection with #{::HighLine.color("knife bastion start", [:bold, :magenta])} to access server."
    ::Kernel.puts '-' * 80
    ::Kernel.puts
    ::Kernel.raise
  }
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method, *args, &block) ⇒ Object

Wraps all original client calls into a with_socks_proxy method.



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# File 'lib/knife-bastion/client_proxy.rb', line 49

def method_missing(method, *args, &block)
  with_socks_proxy do
    @client.send(method, *args, &block)
  end
end

Instance Method Details

#with_socks_proxy ⇒ Object

Routes all network connections through the bastion proxy.



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# File 'lib/knife-bastion/client_proxy.rb', line 56

def with_socks_proxy
  old_socks_server, old_socks_port = ::TCPSocket::socks_server, ::TCPSocket::socks_port
  ::TCPSocket::socks_server, ::TCPSocket::socks_port = '127.0.0.1', @local_port
  yield
rescue *NETWORK_ERRORS => e
  @network_errors_handler.call(e)
ensure
  ::TCPSocket::socks_server, ::TCPSocket::socks_port = old_socks_server, old_socks_port
end