Class: Chef::Provisioning::Transport::SSH

Inherits:
Chef::Provisioning::Transport show all
Defined in:
lib/chef/provisioning/transport/ssh.rb

Defined Under Namespace

Classes: InitialConnectTimeout, SSHResult

Constant Summary

Constants inherited from Chef::Provisioning::Transport

DEFAULT_TIMEOUT

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(host, username, ssh_options, options, global_config) ⇒ SSH

Create a new SSH transport.

Arguments

  • host: the host to connect to, e.g. ‘145.14.51.45’

  • username: the username to connect with

  • ssh_options: a list of options to Net::SSH.start

  • options: a hash of options for the transport itself, including:

    • :prefix: a prefix to send before each command (e.g. “sudo ”)

    • :ssh_pty_enable: set to false to disable pty (some instances don’t support this, most do)

    • :ssh_gateway: the gateway to use, e.g. “[email protected]:222”. nil (the default) means no gateway. If the username is omitted, then the default username is used instead (i.e. the user running chef, or the username configured in .ssh/config).

    • :scp_temp_dir: a directory to use as the temporary location for files that are copied to the host via SCP. Only used if :prefix is set. Default is ‘/tmp’ if unspecified.

  • global_config: an options hash that looks suspiciously similar to Chef::Config, containing at least the key :log_level.

The options are used in

Net::SSH.start(host, username, ssh_options)



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# File 'lib/chef/provisioning/transport/ssh.rb', line 39

def initialize(host, username, ssh_options, options, global_config)
  @host = host
  @username = username
  @ssh_options = ssh_options
  @options = options
  @config = global_config
end

Instance Attribute Details

#config ⇒ Object (readonly)

Returns the value of attribute config.



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# File 'lib/chef/provisioning/transport/ssh.rb', line 51

def config
  @config
end

#host ⇒ Object (readonly)

Returns the value of attribute host.



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# File 'lib/chef/provisioning/transport/ssh.rb', line 47

def host
  @host
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/chef/provisioning/transport/ssh.rb', line 50

def options
  @options
end

#ssh_options ⇒ Object (readonly)

Returns the value of attribute ssh_options.



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# File 'lib/chef/provisioning/transport/ssh.rb', line 49

def ssh_options
  @ssh_options
end

#username ⇒ Object (readonly)

Returns the value of attribute username.



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# File 'lib/chef/provisioning/transport/ssh.rb', line 48

def username
  @username
end

Instance Method Details

#available? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/chef/provisioning/transport/ssh.rb', line 176

def available?
  # If you can't pwd within 10 seconds, you can't pwd
  execute('pwd', :timeout => 10)
  true
rescue Timeout::Error, Errno::EHOSTUNREACH, Errno::ENETUNREACH, Errno::EHOSTDOWN, Errno::ETIMEDOUT, Errno::ECONNREFUSED, Errno::ECONNRESET, Net::SSH::Disconnect
  Chef::Log.debug("#{username}@#{host} unavailable: network connection failed or broke: #{$!.inspect}")
  disconnect
  false
rescue Net::SSH::AuthenticationFailed, Net::SSH::HostKeyMismatch
  Chef::Log.debug("#{username}@#{host} unavailable: SSH authentication error: #{$!.inspect} ")
  disconnect
  false
end

#disconnect ⇒ Object 



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# File 'lib/chef/provisioning/transport/ssh.rb', line 164

def disconnect
  if @session
    begin
      Chef::Log.debug("Closing SSH session on #{username}@#{host}")
      @session.close
    rescue
    ensure
      @session = nil
    end
  end
end

#download_file(path, local_path) ⇒ Object 



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# File 'lib/chef/provisioning/transport/ssh.rb', line 104

def download_file(path, local_path)
  Chef::Log.debug("Downloading file #{path} from #{username}@#{host} to local #{local_path}")
  download(path, local_path)
end

#execute(command, execute_options = {}) ⇒ Object 



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# File 'lib/chef/provisioning/transport/ssh.rb', line 53

def execute(command, execute_options = {})
  Chef::Log.info("Executing #{options[:prefix]}#{command} on #{username}@#{host}")
  stdout = ''
  stderr = ''
  exitstatus = nil
  session # grab session outside timeout, it has its own timeout
  with_execute_timeout(execute_options) do
    channel = session.open_channel do |channel|
      # Enable PTY unless otherwise specified, some instances require this
      unless options[:ssh_pty_enable] == false
        channel.request_pty do |chan, success|
           raise "could not get pty" if !success && options[:ssh_pty_enable]
        end
      end

      channel.exec("#{options[:prefix]}#{command}") do |ch, success|
        raise "could not execute command: #{command.inspect}" unless success

        channel.on_data do |ch2, data|
          stdout << data
          stream_chunk(execute_options, data, nil)
        end

        channel.on_extended_data do |ch2, type, data|
          stderr << data
          stream_chunk(execute_options, nil, data)
        end

        channel.on_request "exit-status" do |ch, data|
          exitstatus = data.read_long
        end
      end
    end

    channel.wait
  end

  Chef::Log.info("Completed #{command} on #{username}@#{host}: exit status #{exitstatus}")
  Chef::Log.debug("Stdout was:\n#{stdout}") if stdout != '' && !options[:stream] && !options[:stream_stdout] && config[:log_level] != :debug
  Chef::Log.info("Stderr was:\n#{stderr}") if stderr != '' && !options[:stream] && !options[:stream_stderr] && config[:log_level] != :debug
  SSHResult.new(command, execute_options, stdout, stderr, exitstatus)
end

#make_url_available_to_remote(local_url) ⇒ Object 



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# File 'lib/chef/provisioning/transport/ssh.rb', line 146

def make_url_available_to_remote(local_url)
  uri = URI(local_url)
  if is_local_machine(uri.host)
    port, host = forward_port(uri.port, uri.host, uri.port, 'localhost')
    if !port
      # Try harder if the port is already taken
      port, host = forward_port(uri.port, uri.host, 0, 'localhost')
      if !port
        raise "Error forwarding port: could not forward #{uri.port} or 0"
      end
    end
    uri.host = host
    uri.port = port
  end
  Chef::Log.info("Port forwarded: local URL #{local_url} is available to #{self.host} as #{uri.to_s} for the duration of this SSH connection.")
  uri.to_s
end

#read_file(path) ⇒ Object

TODO why does #read_file download it to the target host?



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# File 'lib/chef/provisioning/transport/ssh.rb', line 97

def read_file(path)
  Chef::Log.debug("Reading file #{path} from #{username}@#{host}")
  result = StringIO.new
  download(path, result)
  result.string
end

#remote_tempfile(path) ⇒ Object 



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# File 'lib/chef/provisioning/transport/ssh.rb', line 109

def remote_tempfile(path)
  File.join(scp_temp_dir, "#{File.basename(path)}.#{Random.rand(2**32)}")
end

#upload_file(local_path, path) ⇒ Object 



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# File 'lib/chef/provisioning/transport/ssh.rb', line 127

def upload_file(local_path, path)
  execute("mkdir -p #{File.dirname(path)}").error!
  if options[:prefix]
    # Make a tempfile on the other side, upload to that, and sudo mv / chown / etc.
    tempfile = remote_tempfile(path)
    Chef::Log.debug("Uploading #{local_path} to #{tempfile} on #{username}@#{host}")
    Net::SCP.new(session).upload!(local_path, tempfile)
    begin
      execute("mv #{tempfile} #{path}").error!
    rescue
      # Clean up if we were unable to move
      execute("rm #{tempfile}").error!
    end
  else
    Chef::Log.debug("Uploading #{local_path} to #{path} on #{username}@#{host}")
    Net::SCP.new(session).upload!(local_path, path)
  end
end

#write_file(path, content) ⇒ Object 



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# File 'lib/chef/provisioning/transport/ssh.rb', line 113

def write_file(path, content)
  execute("mkdir -p #{File.dirname(path)}").error!
  if options[:prefix]
    # Make a tempfile on the other side, upload to that, and sudo mv / chown / etc.
    tempfile = remote_tempfile(path)
    Chef::Log.debug("Writing #{content.length} bytes to #{tempfile} on #{username}@#{host}")
    Net::SCP.new(session).upload!(StringIO.new(content), tempfile)
    execute("mv #{tempfile} #{path}").error!
  else
    Chef::Log.debug("Writing #{content.length} bytes to #{path} on #{username}@#{host}")
    Net::SCP.new(session).upload!(StringIO.new(content), path)
  end
end