Class: RobotArmy::Connection

Inherits:
Object
  • Object
show all
Defined in:
lib/robot-army/connection.rb

Direct Known Subclasses

OfficerConnection

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(host, user = nil, password = nil) ⇒ Connection

Returns a new instance of Connection.



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# File 'lib/robot-army/connection.rb', line 4

def initialize(host, user=nil, password=nil)
  @host = host
  @user = user
  @password = password
  @closed = true
end

Instance Attribute Details

#host ⇒ Object (readonly)

Returns the value of attribute host.



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# File 'lib/robot-army/connection.rb', line 2

def host
  @host
end

#messenger ⇒ Object (readonly)

Returns the value of attribute messenger.



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# File 'lib/robot-army/connection.rb', line 2

def messenger
  @messenger
end

#password ⇒ Object (readonly)

Returns the value of attribute password.



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# File 'lib/robot-army/connection.rb', line 2

def password
  @password
end

#user ⇒ Object (readonly)

Returns the value of attribute user.



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# File 'lib/robot-army/connection.rb', line 2

def user
  @user
end

Class Method Details

.handle_response(response) ⇒ Object 



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# File 'lib/robot-army/connection.rb', line 156

def self.handle_response(response)
  debug "handling response=#{response.inspect}"
  case response[:status]
  when 'ok'
    return response[:data]
  when 'error'
    raise response[:data]
  when 'warning'
    raise RobotArmy::Warning, response[:data]
  else
    raise RuntimeError, "Unknown response status from remote process: #{response[:status].inspect}"
  end
end

.localhost(user = nil, password = nil, &block) ⇒ Object 



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# File 'lib/robot-army/connection.rb', line 170

def self.localhost(user=nil, password=nil, &block)
  conn = new(:localhost, user, password)
  block ? conn.open(&block) : conn
end

Instance Method Details

#answer_sudo_prompt(stdin, stderr) ⇒ Object 



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# File 'lib/robot-army/connection.rb', line 41

def answer_sudo_prompt(stdin, stderr)
  tries = password.is_a?(Proc) ? 3 : 1
  
  tries.times do
    if asking_for_password?(stderr)
      # ask, and you shall receive
      stdin.puts(password.is_a?(Proc) ?
        password.call : password.to_s)
    end
  end
  
  if asking_for_password?(stderr)
    # ack, that didn't work, bail
    stdin.puts
    stderr.readpartial(1024)
    raise RobotArmy::InvalidPassword
  end
end

#asking_for_password?(stream) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/robot-army/connection.rb', line 33

def asking_for_password?(stream)
  if RobotArmy::IO.has_data?(stream)
    data = RobotArmy::IO.read_data(stream)
    debug "read #{data.inspect}"
    return data && data =~ /#{password_prompt}\n*$/
  end
end

#close ⇒ Object

Raises:



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# File 'lib/robot-army/connection.rb', line 146

def close
  raise RobotArmy::ConnectionNotOpen if closed?
  messenger.post(:command => :exit)
  @closed = true
end

#closed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/robot-army/connection.rb', line 142

def closed?
  @closed
end

#get ⇒ Object 



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# File 'lib/robot-army/connection.rb', line 134

def get
  messenger.get
end

#handle_response(response) ⇒ Object 



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# File 'lib/robot-army/connection.rb', line 152

def handle_response(response)
  self.class.handle_response(response)
end

#info ⇒ Object 



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# File 'lib/robot-army/connection.rb', line 129

def info
  post(:command => :info)
  handle_response(get)
end

#loader ⇒ Object 



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# File 'lib/robot-army/connection.rb', line 11

def loader
  @loader ||= RobotArmy::Loader.new
end

#open(&block) ⇒ Object 



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# File 'lib/robot-army/connection.rb', line 15

def open(&block)
  start_child if closed?
  @closed = false
  unless block_given?
    return self
  else
    begin
      return yield(self)
    ensure
      close unless closed?
    end
  end
end

#password_prompt ⇒ Object 



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# File 'lib/robot-army/connection.rb', line 29

def password_prompt
  @password_prompt ||= RobotArmy.random_string
end

#post(*args) ⇒ Object 



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# File 'lib/robot-army/connection.rb', line 138

def post(*args)
  messenger.post(*args)
end

#start_child ⇒ Object 



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# File 'lib/robot-army/connection.rb', line 60

def start_child
  begin
    ##
    ## bootstrap the child process
    ##
    
    # small hack to retain control of stdin
    cmd = %{ruby -rbase64 -e "eval(Base64.decode64(STDIN.gets(%(|))))"}
    if user
      # use sudo with user's home dir, custom prompt, reading password from stdin
      cmd = %{sudo -H -u #{user} -p #{password_prompt} -S #{cmd}}
    end
    cmd = "ssh #{host} '#{cmd}'" unless host == :localhost
    debug "running #{cmd}"
    
    loader.libraries.replace $TESTING ? 
      [File.join(File.dirname(__FILE__), '..', 'robot-army')] : %w[rubygems robot-army]
    
    stdin, stdout, stderr = Open3.popen3 cmd
    stdin.sync = stdout.sync = stderr.sync = true
    
    # look for the prompt
    answer_sudo_prompt(stdin, stderr) if user && password
    
    ruby = loader.render
    code = Base64.encode64(ruby)
    stdin << code << '|'
    
    
    ##
    ## make sure it was loaded okay
    ##
    
    @messenger = RobotArmy::Messenger.new(stdout, stdin)
    response = messenger.get
    
    if response
      case response[:status]
      when 'error'
        $stderr.puts "Error trying to execute: #{ruby.gsub(/^/, '  ')}\n"
        raise response[:data]
      when 'ok'
        # yay! established connection
      end
    else
      # try to get stderr
      begin
        require 'timeout'
        err = timeout(1){ "process stderr: #{stderr.read}" }
      rescue Timeout::Error
        err = 'additionally, failed to get stderr'
      end
    
      raise "Failed to start remote ruby process. #{err}"
    end
  
    ##
    ## finish up
    ##
  
    @closed = false
  rescue Object => e
    $stderr.puts "Failed to establish connection to #{host}: #{e.message}"
    raise e
  ensure
    @closed = true
  end
end