Class: RightScraper::Processes::SSHAgent

Inherits:
Object
  • Object
show all
Defined in:
lib/right_scraper/processes/ssh.rb

Overview

Manage a dedicated SSH agent.

Defined Under Namespace

Classes: SSHAgentError

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ SSHAgent

Returns a new instance of SSHAgent.



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# File 'lib/right_scraper/processes/ssh.rb', line 36

def initialize
  @display = ENV['DISPLAY']
  @askpass = ENV['SSH_ASKPASS']
  @sshauth = ENV['SSH_AUTH_SOCK']
  @agentpid = ENV['SSH_AGENT_PID']
  @home = ENV['HOME']
end

Class Method Details

.with ⇒ Object

Execute the block in a new ssh agent. Equivalent to

agent = SSHAgent.new
begin
 agent.open
 ...
ensure
 agent.close
end



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# File 'lib/right_scraper/processes/ssh.rb', line 177

def self.with
  agent = SSHAgent.new
  begin
    agent.open
    yield agent
  ensure
    agent.close
  end
end

Instance Method Details

#add_key(key) ⇒ Object

Add the given key data to the ssh agent.

Parameters

key(String)

ssh key data



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# File 'lib/right_scraper/processes/ssh.rb', line 122

def add_key(key)
  begin
    file = Tempfile.new('key')
    file.puts(key)
    file.close

    add_keyfile(file.path)
  ensure
    file.close(true) unless file.nil?
  end
end

#add_keyfile(file) ⇒ Object

Add the key data in the given file to the ssh agent.

Parameters

file(String)

file containing key data



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# File 'lib/right_scraper/processes/ssh.rb', line 138

def add_keyfile(file)
  @ssh_add_output = ::RightScale::RightPopen::SafeOutputBuffer.new
  cmd = ['ssh-add', file]
  ::RightScale::RightPopen.popen3_sync(
    cmd,
    :target          => self,
    :inherit_io      => true,  # avoid killing any rails connection
    :stderr_handler  => :output_ssh_add,
    :stdout_handler  => :output_ssh_add,
    :timeout_handler => :timeout_ssh_add,
    :exit_handler    => :exit_ssh_add,
    :timeout_seconds => 10)
end

#close ⇒ Object

Close the connection to the SSH agent, and restore ENV.



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# File 'lib/right_scraper/processes/ssh.rb', line 75

def close
  begin
    FileUtils.remove_entry_secure @dir
    lay_to_rest
  ensure
    setvar 'SSH_AGENT_PID', @agentpid
    setvar 'DISPLAY', @display
    setvar 'SSH_ASKPASS', @askpass
    setvar 'SSH_AUTH_SOCK', @sshauth
    setvar 'HOME', @home
  end
end

#exit_ssh_add(status) ⇒ Object 



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# File 'lib/right_scraper/processes/ssh.rb', line 160

def exit_ssh_add(status)
  unless status.success?
    @ssh_add_output.safe_buffer_data("Exit code = #{status.exitstatus}")
    raise SSHAgentError, "ssh-add failed: #{@ssh_add_output.display_text}"
  end
  true
end

#exit_ssh_agent(status) ⇒ Object 



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# File 'lib/right_scraper/processes/ssh.rb', line 110

def exit_ssh_agent(status)
  unless @interupted_to_close || status.success?
    @ssh_agent_output.safe_buffer_data("Exit code = #{status.exitstatus}")
    raise SSHAgentError, "ssh-agent failed: #{@ssh_agent_output.display_text}"
  end
  true
end

#open ⇒ Object

Open a connection to the SSH agent and set ENV appropriately.



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# File 'lib/right_scraper/processes/ssh.rb', line 46

def open
  ENV['SSH_ASKPASS'] = File.expand_path(File.join(File.dirname(__FILE__),
                                                  '..', '..', '..',
                                                  'scripts',
                                                  'stub_ssh_askpass'))
  ENV['HOME'] = "/dev/null"
  @dir = Dir.mktmpdir
  @socketfile = File.join(@dir, "agent")
  @process = nil
  @interupted_to_close = false
  @ssh_agent_output = ::RightScale::RightPopen::SafeOutputBuffer.new
  cmd = ['ssh-agent', '-a', @socketfile, '-d']
  ::RightScale::RightPopen.popen3_sync(
    cmd,
    :target          => self,
    :inherit_io      => true,  # avoid killing any rails connection
    :watch_handler   => :watch_ssh_agent,
    :stderr_handler  => :output_ssh_agent,
    :stdout_handler  => :output_ssh_agent,
    :timeout_handler => :timeout_ssh_agent,
    :exit_handler    => :exit_ssh_agent,
    :timeout_seconds => 10)
  if @process
    ENV['SSH_AGENT_PID'] = @process.pid.to_s
    ENV['SSH_AUTH_SOCK'] = @socketfile
  end
end

#output_ssh_add(data) ⇒ Object 



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# File 'lib/right_scraper/processes/ssh.rb', line 152

def output_ssh_add(data)
  @ssh_add_output.safe_buffer_data(data)
end

#output_ssh_agent(data) ⇒ Object 



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# File 'lib/right_scraper/processes/ssh.rb', line 88

def output_ssh_agent(data)
  @ssh_agent_output.safe_buffer_data(data)
end

#timeout_ssh_add ⇒ Object

Raises:



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# File 'lib/right_scraper/processes/ssh.rb', line 156

def timeout_ssh_add
  raise SSHAgentError, 'ssh-add timed out'
end

#timeout_ssh_agent ⇒ Object 



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# File 'lib/right_scraper/processes/ssh.rb', line 104

def timeout_ssh_agent
  unless @interupted_to_close
    raise SSHAgentError, 'Timed out waiting for ssh-agent control socket to appear'
  end
end

#watch_ssh_agent(process) ⇒ TrueClass|FalseClass

abandons watch when socket file appears

Returns:

  • (TrueClass|FalseClass) —

    true to continue watch, false to abandon



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# File 'lib/right_scraper/processes/ssh.rb', line 95

def watch_ssh_agent(process)
  if @interupted_to_close
    true
  else
    @process = process
    !::File.exists?(@socketfile)
  end
end