require 'chef/provisioning'
require 'chef/provisioning/fog_driver/recipe_dsl'

require 'chef/provisioning/driver'
require 'chef/provisioning/machine/windows_machine'
require 'chef/provisioning/machine/unix_machine'
require 'chef/provisioning/machine_spec'
require 'chef/provisioning/convergence_strategy/install_msi'
require 'chef/provisioning/convergence_strategy/install_sh'
require 'chef/provisioning/convergence_strategy/install_cached'
require 'chef/provisioning/convergence_strategy/no_converge'
require 'chef/provisioning/transport/ssh'
require 'chef/provisioning/transport/winrm'
require 'chef/provisioning/fog_driver/version'

require 'fog'
require 'fog/core'
require 'fog/compute'
require 'socket'
require 'etc'
require 'time'
require 'cheffish/merged_config'
require 'chef/provisioning/fog_driver/recipe_dsl'

class Chef
module Provisioning
module FogDriver
  # Provisions cloud machines with the Fog driver.
  #
  # ## Fog Driver URLs
  #
  # All Chef Provisioning drivers use URLs to uniquely identify a driver's "bucket" of machines.
  # Fog URLs are of the form fog:<provider>:<identifier:> - see individual providers
  # for sample URLs.
  #
  # Identifier is generally something uniquely identifying the account.  If multiple
  # users can access the account, the identifier should be the same for all of
  # them (do not use the username in these cases, use an account ID or auth server
  # URL).
  #
  # In particular, the identifier should be specific enough that if you create a
  # server with a driver with this URL, the server should be retrievable from
  # the same URL *no matter what else changes*. For example, an AWS account ID
  # is *not* enough for this--if you varied the region, you would no longer see
  # your server in the list.  Thus, AWS uses both the account ID and the region.
  #
  # ## Supporting a new Fog provider
  #
  # The Fog driver does not immediately support all Fog providers out of the box.
  # Some minor work needs to be done to plug them into Chef.
  #
  # To add a new supported Fog provider, pick an appropriate identifier, go to
  # from_provider and compute_options_for, and add the new provider in the case
  # statements so that URLs for your fog provider can be generated.  If your
  # cloud provider has environment variables or standard config files (like
  # ~/.aws/credentials or ~/.aws/config), you can read those and merge that information
  # in the compute_options_for function.
  #
  # ## Location format
  #
  # All machines have a location hash to find them.  These are the keys used by
  # the fog provisioner:
  #
  # - driver_url: fog:<driver>:<unique_account_info>
  # - server_id: the ID of the server so it can be found again
  # - created_at: timestamp server was created
  # - started_at: timestamp server was last started
  # - is_windows, ssh_username, sudo, use_private_ip_for_ssh: copied from machine_options
  #
  # ## Machine options
  #
  # Machine options (for allocation and readying the machine) include:
  #
  # - bootstrap_options: hash of options to pass to compute.servers.create
  # - is_windows: true if windows.  TODO detect this from ami?
  # - create_timeout: the time to wait for the instance to boot to ssh (defaults to 180)
  # - start_timeout: the time to wait for the instance to start (defaults to 180)
  # - ssh_timeout: the time to wait for ssh to be available if the instance is detected as up (defaults to 20)
  # - ssh_username: username to use for ssh
  # - sudo: true to prefix all commands with "sudo"
  # - use_private_ip_for_ssh: hint to use private floating_ip when available
  # - convergence_options: hash of options for the convergence strategy
  #   - chef_client_timeout: the time to wait for chef-client to finish
  #   - chef_server - the chef server to point convergence at
  #
  # Example bootstrap_options for ec2:
  #
  #   :bootstrap_options => {
  #     :image_id =>'ami-311f2b45',
  #     :flavor_id =>'t1.micro',
  #     :key_name => 'key-pair-name'
  #   }
  #
  class Driver < Provisioning::Driver
    @@ip_pool_lock = Mutex.new

    include Chef::Mixin::ShellOut

    DEFAULT_OPTIONS = {
      :create_timeout => 180,
      :start_timeout => 180,
      :ssh_timeout => 20
    }

    class << self
      alias :__new__ :new

      def inherited(klass)
        class << klass
          alias :new :__new__
        end
      end
    end

    @@registered_provider_classes = {}
    def self.register_provider_class(name, driver)
      @@registered_provider_classes[name] = driver
    end

    def self.provider_class_for(provider)
      require "chef/provisioning/fog_driver/providers/#{provider.downcase}"
      @@registered_provider_classes[provider]
    end

    def self.new(driver_url, config)
      provider = driver_url.split(':')[1]
      provider_class_for(provider).new(driver_url, config)
    end

    # Passed in a driver_url, and a config in the format of Driver.config.
    def self.from_url(driver_url, config)
      Driver.new(driver_url, config)
    end

    def self.canonicalize_url(driver_url, config)
      _, provider, id = driver_url.split(':', 3)
      config, id = provider_class_for(provider).compute_options_for(provider, id, config)
      [ "fog:#{provider}:#{id}", config ]
    end

    # Passed in a config which is *not* merged with driver_url (because we don't
    # know what it is yet) but which has the same keys
    def self.from_provider(provider, config)
      # Figure out the options and merge them into the config
      config, id = provider_class_for(provider).compute_options_for(provider, nil, config)

      driver_url = "fog:#{provider}:#{id}"

      Provisioning.driver_for_url(driver_url, config)
    end

    # Create a new fog driver.
    #
    # ## Parameters
    # driver_url - URL of driver.  "fog:<provider>:<provider_id>"
    # config - configuration.  :driver_options, :keys, :key_paths and :log_level are used.
    #   driver_options is a hash with these possible options:
    #   - compute_options: the hash of options to Fog::Compute.new.
    #   - aws_config_file: aws config file (defaults: ~/.aws/credentials, ~/.aws/config)
    #   - aws_csv_file: aws csv credentials file downloaded from EC2 interface
    #   - aws_profile: profile name to use for credentials
    #   - aws_credentials: AWSCredentials object. (will be created for you by default)
    #   - log_level: :debug, :info, :warn, :error
    def initialize(driver_url, config)
      super(driver_url, config)
      if config[:log_level] == :debug
        Fog::Logger[:debug] = ::STDERR
        Excon.defaults[:debug_request] = true
        Excon.defaults[:debug_response] = true
      end
    end

    def compute_options
      driver_options[:compute_options].to_hash || {}
    end

    def provider
      compute_options[:provider]
    end

    # Acquire a machine, generally by provisioning it.  Returns a Machine
    # object pointing at the machine, allowing useful actions like setup,
    # converge, execute, file and directory.
    def allocate_machine(action_handler, machine_spec, machine_options)
      # If the server does not exist, create it
      create_servers(action_handler, { machine_spec => machine_options }, Chef::ChefFS::Parallelizer.new(0))
      machine_spec
    end

    def allocate_machines(action_handler, specs_and_options, parallelizer)
      create_servers(action_handler, specs_and_options, parallelizer) do |machine_spec, server|
        yield machine_spec
      end
      specs_and_options.keys
    end

    def ready_machine(action_handler, machine_spec, machine_options)
      server = server_for(machine_spec)
      if server.nil?
        raise "Machine #{machine_spec.name} does not have a server associated with it, or server does not exist."
      end

      # Start the server if needed, and wait for it to start
      start_server(action_handler, machine_spec, server)
      wait_until_ready(action_handler, machine_spec, machine_options, server)

      # Attach/detach floating IPs if necessary
      converge_floating_ips(action_handler, machine_spec, machine_options, server)

      begin
        wait_for_transport(action_handler, machine_spec, machine_options, server)
      rescue Fog::Errors::TimeoutError
        # Only ever reboot once, and only if it's been less than 10 minutes since we stopped waiting
        if machine_spec.location['started_at'] || remaining_wait_time(machine_spec, machine_options) < -(10*60)
          raise
        else
          # Sometimes (on EC2) the machine comes up but gets stuck or has
          # some other problem.  If this is the case, we restart the server
          # to unstick it.  Reboot covers a multitude of sins.
          Chef::Log.warn "Machine #{machine_spec.name} (#{server.id} on #{driver_url}) was started but SSH did not come up.  Rebooting machine in an attempt to unstick it ..."
          restart_server(action_handler, machine_spec, server)
          wait_until_ready(action_handler, machine_spec, machine_options, server)
          wait_for_transport(action_handler, machine_spec, machine_options, server)
        end
      end

      machine_for(machine_spec, machine_options, server)
    end

    # Connect to machine without acquiring it
    def connect_to_machine(machine_spec, machine_options)
      machine_for(machine_spec, machine_options)
    end

    def destroy_machine(action_handler, machine_spec, machine_options)
      server = server_for(machine_spec)
      if server
        action_handler.perform_action "destroy machine #{machine_spec.name} (#{machine_spec.location['server_id']} at #{driver_url})" do
          server.destroy
          machine_spec.location = nil
        end
      end
      strategy = convergence_strategy_for(machine_spec, machine_options)
      strategy.cleanup_convergence(action_handler, machine_spec)
    end

    def stop_machine(action_handler, machine_spec, machine_options)
      server = server_for(machine_spec)
      if server
        action_handler.perform_action "stop machine #{machine_spec.name} (#{server.id} at #{driver_url})" do
          server.stop
        end
      end
    end

    def image_for(image_spec)
      compute.images.get(image_spec.location['image_id'])
    end

    def compute
      @compute ||= Fog::Compute.new(compute_options)
    end

    # Not meant to be part of public interface
    def transport_for(machine_spec, machine_options, server, action_handler = nil)
      if machine_spec.location['is_windows']
        action_handler.report_progress "Waiting for admin password on #{machine_spec.name} to be ready (may take up to 15 minutes)..." if action_handler
        transport = create_winrm_transport(machine_spec, machine_options, server)
        action_handler.report_progress 'Admin password available ...' if action_handler
        transport
      else
        create_ssh_transport(machine_spec, machine_options, server)
      end
    end

    protected

    def option_for(machine_options, key)
      machine_options[key] || DEFAULT_OPTIONS[key]
    end

    def creator
      raise "unsupported fog provider #{provider} (please implement #creator)"
    end

    def create_servers(action_handler, specs_and_options, parallelizer, &block)
      specs_and_servers = servers_for(specs_and_options.keys)

      # Get the list of servers which exist, segmented by their bootstrap options
      # (we will try to create a set of servers for each set of bootstrap options
      # with create_many)
      by_bootstrap_options = {}
      specs_and_options.each do |machine_spec, machine_options|
        server = specs_and_servers[machine_spec]
        if server
          if %w(terminated archive).include?(server.state) # Can't come back from that
            Chef::Log.warn "Machine #{machine_spec.name} (#{server.id} on #{driver_url}) is terminated.  Recreating ..."
          else
            yield machine_spec, server if block_given?
            next
          end
        elsif machine_spec.location
          Chef::Log.warn "Machine #{machine_spec.name} (#{machine_spec.location['server_id']} on #{driver_url}) no longer exists.  Recreating ..."
        end

        bootstrap_options = bootstrap_options_for(action_handler, machine_spec, machine_options)
        by_bootstrap_options[bootstrap_options] ||= []
        by_bootstrap_options[bootstrap_options] << machine_spec
      end

      # Create the servers in parallel
      parallelizer.parallelize(by_bootstrap_options) do |bootstrap_options, machine_specs|
        machine_description = if machine_specs.size == 1
          "machine #{machine_specs.first.name}"
        else
          "machines #{machine_specs.map { |s| s.name }.join(", ")}"
        end
        description = [ "creating #{machine_description} on #{driver_url}" ]
        bootstrap_options.each_pair { |key,value| description << "  #{key}: #{value.inspect}" }
        action_handler.report_progress description
        if action_handler.should_perform_actions
          # Actually create the servers
          create_many_servers(machine_specs.size, bootstrap_options, parallelizer) do |server|

            # Assign each one to a machine spec
            machine_spec = machine_specs.pop
            machine_options = specs_and_options[machine_spec]
            machine_spec.location = {
              'driver_url' => driver_url,
              'driver_version' => FogDriver::VERSION,
              'server_id' => server.id,
              'creator' => creator,
              'allocated_at' => Time.now.to_i
            }
            machine_spec.location['key_name'] = bootstrap_options[:key_name] if bootstrap_options[:key_name]
            %w(is_windows ssh_username sudo use_private_ip_for_ssh ssh_gateway).each do |key|
              machine_spec.location[key] = machine_options[key.to_sym] if machine_options[key.to_sym]
            end
            action_handler.performed_action "machine #{machine_spec.name} created as #{server.id} on #{driver_url}"

            yield machine_spec, server if block_given?
          end

          if machine_specs.size > 0
            raise "Not all machines were created by create_many_servers!"
          end
        end
      end.to_a
    end

    def create_many_servers(num_servers, bootstrap_options, parallelizer)
      parallelizer.parallelize(1.upto(num_servers)) do |i|
        clean_bootstrap_options = Marshal.load(Marshal.dump(bootstrap_options)) # Prevent destructive operations on bootstrap_options.
        server = compute.servers.create(clean_bootstrap_options)
        yield server if block_given?
        server
      end.to_a
    end

    def start_server(action_handler, machine_spec, server)
      # If it is stopping, wait for it to get out of "stopping" transition state before starting
      if server.state == 'stopping'
        action_handler.report_progress "wait for #{machine_spec.name} (#{server.id} on #{driver_url}) to finish stopping ..."
        server.wait_for { server.state != 'stopping' }
        action_handler.report_progress "#{machine_spec.name} is now stopped"
      end

      if server.state == 'stopped'
        action_handler.perform_action "start machine #{machine_spec.name} (#{server.id} on #{driver_url})" do
          server.start
          machine_spec.location['started_at'] = Time.now.to_i
        end
        machine_spec.save(action_handler)
      end
    end

    def restart_server(action_handler, machine_spec, server)
      action_handler.perform_action "restart machine #{machine_spec.name} (#{server.id} on #{driver_url})" do
        server.reboot
        machine_spec.location['started_at'] = Time.now.to_i
      end
      machine_spec.save(action_handler)
    end

    def remaining_wait_time(machine_spec, machine_options)
      if machine_spec.location['started_at']
        timeout = option_for(machine_options, :start_timeout) - (Time.now.utc - parse_time(machine_spec.location['started_at']))
      else
        timeout = option_for(machine_options, :create_timeout) - (Time.now.utc - parse_time(machine_spec.location['allocated_at']))
      end
      timeout > 0 ? timeout : 0.01
    end

    def parse_time(value)
      if value.is_a?(String)
        Time.parse(value)
      else
        Time.at(value)
      end
    end

    def wait_until_ready(action_handler, machine_spec, machine_options, server)
      if !server.ready?
        if action_handler.should_perform_actions
          action_handler.report_progress "waiting for #{machine_spec.name} (#{server.id} on #{driver_url}) to be ready ..."
          server.wait_for(remaining_wait_time(machine_spec, machine_options)) { ready? }
          action_handler.report_progress "#{machine_spec.name} is now ready"
        end
      end
    end

    def wait_for_transport(action_handler, machine_spec, machine_options, server)

      transport = transport_for(machine_spec, machine_options, server, action_handler)
      if !transport.available?
        if action_handler.should_perform_actions
          action_handler.report_progress "waiting for #{machine_spec.name} (#{server.id} on #{driver_url}) to be connectable (transport up and running) ..."

          _self = self

          server.wait_for(remaining_wait_time(machine_spec, machine_options)) do
            transport.available?
          end
          action_handler.report_progress "#{machine_spec.name} is now connectable"
        end
      end
    end

    def converge_floating_ips(action_handler, machine_spec, machine_options, server)
      pool = option_for(machine_options, :floating_ip_pool)
      floating_ip = option_for(machine_options, :floating_ip)
      attached_floating_ips = find_floating_ips(server)
      if pool

        Chef::Log.debug "Attaching IP from pool #{pool}"
        if attached_floating_ips.size > 0
          Chef::Log.info "Server already assigned attached_floating_ips `#{attached_floating_ips}`"
        elsif
          action_handler.perform_action "Attaching floating IP from pool `#{pool}`" do
            attach_ip_from_pool(server, pool)
          end
        end

      elsif floating_ip

        Chef::Log.debug "Attaching given IP #{floating_ip}"
        if attached_floating_ips.include? floating_ip
          Chef::Log.info "Address <#{floating_ip}> already allocated"
        else
          action_handler.perform_action "Attaching floating IP #{floating_ip}" do
            attach_ip(server, floating_ip)
          end
        end

      elsif !attached_floating_ips.empty?

        # If nothing is assigned, lets remove any floating IPs
        Chef::Log.debug 'Missing :floating_ip_pool or :floating_ip, removing attached floating IPs'
        action_handler.perform_action "Removing floating IPs #{attached_floating_ips}" do
          attached_floating_ips.each do |ip|
            server.disassociate_address(ip)
          end
          server.reload
        end

      end
    end

    # Find all attached floating IPs from all networks
    def find_floating_ips(server)
      floating_ips = []
      server.addresses.each do |network, addrs|
        addrs.each do | full_addr |
          if full_addr['OS-EXT-IPS:type'] == 'floating'
            floating_ips << full_addr['addr']
          end
        end
      end
      floating_ips
    end

    # Attach IP to machine from IP pool
    # Code taken from kitchen-openstack driver
    #    https://github.com/test-kitchen/kitchen-openstack/blob/master/lib/kitchen/driver/openstack.rb
    def attach_ip_from_pool(server, pool)
      @@ip_pool_lock.synchronize do
        Chef::Log.info "Attaching floating IP from <#{pool}> pool"
        free_addrs = compute.addresses.map do |i|
          i.ip if i.fixed_ip.nil? && i.instance_id.nil? && i.pool == pool
        end.compact
        if free_addrs.empty?
          raise RuntimeError, "No available IPs in pool <#{pool}>"
        end
        attach_ip(server, free_addrs[0])
      end
    end

    # Attach given IP to machine, assign it as public
    # Code taken from kitchen-openstack driver
    #    https://github.com/test-kitchen/kitchen-openstack/blob/master/lib/kitchen/driver/openstack.rb
    def attach_ip(server, ip)
      Chef::Log.info "Attaching floating IP <#{ip}>"
      server.associate_address ip
      server.reload
    end

    def symbolize_keys(options)
      options.inject({}) do |result,(key,value)|
        result[key.to_sym] = value
        result
      end
    end

    def server_for(machine_spec)
      if machine_spec.location
        compute.servers.get(machine_spec.location['server_id'])
      else
        nil
      end
    end

    def servers_for(machine_specs)
      result = {}
      machine_specs.each do |machine_spec|
        if machine_spec.location
          if machine_spec.location['driver_url'] != driver_url
            raise "Switching a machine's driver from #{machine_spec.location['driver_url']} to #{driver_url} for is not currently supported!  Use machine :destroy and then re-create the machine on the new driver."
          end
          result[machine_spec] = compute.servers.get(machine_spec.location['server_id'])
        else
          result[machine_spec] = nil
        end
      end
      result
    end

    @@chef_default_lock = Mutex.new

    def overwrite_default_key_willy_nilly(action_handler, machine_spec)
      if machine_spec.location &&
         Gem::Version.new(machine_spec.location['driver_version']) < Gem::Version.new('0.10')
        return 'metal_default'
      end

      driver = self
      updated = @@chef_default_lock.synchronize do
        Provisioning.inline_resource(action_handler) do
          fog_key_pair 'chef_default' do
            driver driver
            allow_overwrite true
          end
        end
      end
      if updated
        # Only warn the first time
        Chef::Log.warn("Using chef_default key, which is not shared between machines!  It is recommended to create an AWS key pair with the fog_key_pair resource, and set :bootstrap_options => { :key_name => <key name> }")
      end
      'chef_default'
    end

    def bootstrap_options_for(action_handler, machine_spec, machine_options)
      bootstrap_options = symbolize_keys(machine_options[:bootstrap_options] || {})

      bootstrap_options[:tags]  = default_tags(machine_spec, bootstrap_options[:tags] || {})

      bootstrap_options[:name] ||= machine_spec.name

      bootstrap_options
    end

    def default_tags(machine_spec, bootstrap_tags = {})
      tags = {
          'Name' => machine_spec.name,
          'BootstrapId' => machine_spec.id,
          'BootstrapHost' => Socket.gethostname,
          'BootstrapUser' => Etc.getlogin
      }
      # User-defined tags override the ones we set
      tags.merge(bootstrap_tags)
    end

    def machine_for(machine_spec, machine_options, server = nil)
      server ||= server_for(machine_spec)
      if !server
        raise "Server for node #{machine_spec.name} has not been created!"
      end

      if machine_spec.location['is_windows']
        Machine::WindowsMachine.new(machine_spec, transport_for(machine_spec, machine_options, server), convergence_strategy_for(machine_spec, machine_options))
      else
        Machine::UnixMachine.new(machine_spec, transport_for(machine_spec, machine_options, server), convergence_strategy_for(machine_spec, machine_options))
      end
    end

    def convergence_strategy_for(machine_spec, machine_options)
      # Defaults
      if !machine_spec.location
        return ConvergenceStrategy::NoConverge.new(machine_options[:convergence_options], config)
      end

      if machine_spec.location['is_windows']
        ConvergenceStrategy::InstallMsi.new(machine_options[:convergence_options], config)
      elsif machine_options[:cached_installer] == true
        ConvergenceStrategy::InstallCached.new(machine_options[:convergence_options], config)
      else
        ConvergenceStrategy::InstallSh.new(machine_options[:convergence_options], config)
      end
    end

    # Get the private key for a machine - prioritize the server data, fall back to the
    # the machine spec data, and if that doesn't work, raise an exception.
    # @param [Hash] machine_spec Machine spec data
    # @param [Hash] machine_options Machine options
    # @param [Chef::Provisioning::Machine] server a Machine representing the server
    # @return [String] PEM-encoded private key
    def private_key_for(machine_spec, machine_options, server)
      if server.respond_to?(:private_key) && server.private_key
         server.private_key
      elsif server.respond_to?(:key_name) && server.key_name
        key = get_private_key(server.key_name)
        if !key
          raise "Server has key name '#{server.key_name}', but the corresponding private key was not found locally.  Check if the key is in Chef::Config.private_key_paths: #{Chef::Config.private_key_paths.join(', ')}"
        end
        key
      elsif machine_spec.location['key_name']
        key = get_private_key(machine_spec.location['key_name'])
        if !key
          raise "Server was created with key name '#{machine_spec.location['key_name']}', but the corresponding private key was not found locally.  Check if the key is in Chef::Config.private_key_paths: #{Chef::Config.private_key_paths.join(', ')}"
        end
        key
      elsif machine_options[:bootstrap_options][:key_path]
        IO.read(machine_options[:bootstrap_options][:key_path])
      elsif machine_options[:bootstrap_options][:key_name]
        get_private_key(machine_options[:bootstrap_options][:key_name])
      else
        # TODO make a way to suggest other keys to try ...
        raise "No key found to connect to #{machine_spec.name} (#{machine_spec.location.inspect})!"
      end
    end

    def ssh_options_for(machine_spec, machine_options, server)
      result = {
        :auth_methods => [ 'publickey' ],
        :host_key_alias => "#{server.id}.#{provider}"
      }.merge(machine_options[:ssh_options] || {})
      # Grab key_data from the user's config if not specified
      unless result.has_key?(:key_data)
        result[:keys_only] = true
        result[:key_data] = [ private_key_for(machine_spec, machine_options, server) ]
      end
      result
    end

    def default_ssh_username
      'root'
    end

    def create_winrm_transport(machine_spec, machine_options, server)
      fail "This provider doesn't know how to do that."
    end

    def create_ssh_transport(machine_spec, machine_options, server)
      ssh_options = ssh_options_for(machine_spec, machine_options, server)
      username = machine_spec.location['ssh_username'] || default_ssh_username
      if machine_options.has_key?(:ssh_username) && machine_options[:ssh_username] != machine_spec.location['ssh_username']
        Chef::Log.warn("Server #{machine_spec.name} was created with SSH username #{machine_spec.location['ssh_username']} and machine_options specifies username #{machine_options[:ssh_username]}.  Using #{machine_spec.location['ssh_username']}.  Please edit the node and change the chef_provisioning.location.ssh_username attribute if you want to change it.")
      end
      options = {}
      if machine_spec.location[:sudo] || (!machine_spec.location.has_key?(:sudo) && username != 'root')
        options[:prefix] = 'sudo '
      end

      remote_host = nil
      if machine_spec.location['use_private_ip_for_ssh']
        remote_host = server.private_ip_address
      elsif !server.public_ip_address
        Chef::Log.warn("Server #{machine_spec.name} has no public floating_ip address.  Using private floating_ip '#{server.private_ip_address}'.  Set driver option 'use_private_ip_for_ssh' => true if this will always be the case ...")
        remote_host = server.private_ip_address
      elsif server.public_ip_address
        remote_host = server.public_ip_address
      else
        raise "Server #{server.id} has no private or public IP address!"
      end

      #Enable pty by default
      options[:ssh_pty_enable] = true
      options[:ssh_gateway] = machine_spec.location['ssh_gateway'] if machine_spec.location.has_key?('ssh_gateway')

      Transport::SSH.new(remote_host, username, ssh_options, options, config)
    end

    def self.compute_options_for(provider, id, config)
      raise "unsupported fog provider #{provider}"
    end
  end
end
end
end