Class: RemoteCommandHandler

Inherits:
Object
  • Object
show all
Defined in:
lib/help/remote_command_handler.rb

Overview

Provides methods to be executed via ssh to remote instances.

Direct Known Subclasses

DmCryptHelper

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ RemoteCommandHandler

Returns a new instance of RemoteCommandHandler.



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# File 'lib/help/remote_command_handler.rb', line 9

def initialize()
  @logger = Logger.new(STDOUT)
  @use_sudo = false
end

Instance Attribute Details

#logger ⇒ Object

Returns the value of attribute logger.



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# File 'lib/help/remote_command_handler.rb', line 8

def logger
  @logger
end

#ssh_session ⇒ Object

Returns the value of attribute ssh_session.



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# File 'lib/help/remote_command_handler.rb', line 8

def ssh_session
  @ssh_session
end

#use_sudo ⇒ Object

Returns the value of attribute use_sudo.



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# File 'lib/help/remote_command_handler.rb', line 8

def use_sudo
  @use_sudo
end

Instance Method Details

#connect(ip, user, key_data, timeout = 30) ⇒ Object

Connect to the machine as root using keydata from a keyfile. Params:

  • ip: ip address of the machine to connect to

  • user: user name

  • key_data: key_data to be used for authentication



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# File 'lib/help/remote_command_handler.rb', line 28

def connect(ip, user, key_data, timeout = 30)
  @ssh_session = Net::SSH.start(ip, user, {:key_data => [key_data], :timeout => timeout})
  @use_sudo = true unless user.strip == 'root'
end

#connect_with_keyfile(ip, user_name, keyfile, timeout = 30) ⇒ Object

Connect to the machine as root using a keyfile. Params:

  • ip: ip address of the machine to connect to

  • keyfile: path of the keyfile to be used for authentication



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# File 'lib/help/remote_command_handler.rb', line 18

def connect_with_keyfile(ip, user_name, keyfile, timeout = 30)
  @ssh_session = Net::SSH.start(ip, user_name, {:keys => [keyfile], :timeout => timeout})
  @use_sudo = true unless user_name.strip == 'root'
end

#create_filesystem(fs_type, volume) ⇒ Object 



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# File 'lib/help/remote_command_handler.rb', line 69

def create_filesystem(fs_type, volume)
  e = "mkfs -t #{fs_type} #{volume}"
  remote_execute(e, "y") #TODO: quiet mode?
end

#disconnect ⇒ Object

Disconnect the current handler



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# File 'lib/help/remote_command_handler.rb', line 34

def disconnect
  @ssh_session.close
end

#drive_mounted?(path) ⇒ Boolean

Checks if the drive on path is mounted

Returns:

  • (Boolean) 


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# File 'lib/help/remote_command_handler.rb', line 85

def drive_mounted?(path)
  #check if drive mounted
  drive_found = stdout_contains?("mount", "on #{path} type")
  if drive_found
    return file_exists?(path)
  else
    @logger.debug "not mounted (since #{path} non-existing)"
    false
  end
end

#drive_mounted_as?(device, path) ⇒ Boolean

Checks if the drive on path is mounted with the specific device

Returns:

  • (Boolean) 


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# File 'lib/help/remote_command_handler.rb', line 97

def drive_mounted_as?(device, path)
  #check if drive mounted
  stdout_contains?("mount", "#{device} on #{path} type")
end

#echo(data, file) ⇒ Object 



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# File 'lib/help/remote_command_handler.rb', line 162

def echo(data, file)
  exec = "echo #{data} > #{file}"
  @logger.debug "going to execute #{exec}"
  remote_execute(exec, nil, true)
  if !file_exists?(file)
    raise Exception.new("file #{file} could not be created")
  end
end

#file_exists?(path) ⇒ Boolean

Check if the path/file specified exists

Returns:

  • (Boolean) 


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# File 'lib/help/remote_command_handler.rb', line 39

def file_exists?(path)
  remote_execute("ls #{path}")
end

#get_output(exec_string, push_data = nil, stdout = [], stderr = []) ⇒ Object

Executes the specified #exec_string on a remote session specified as #ssh_session. When #push_data is specified, the data will be used as input for the command and thus allows to respond in advance to commands that ask the user something. It returns stdout. When #stdout or #stderr is specified as arrays, the respective output is also written into those arrays.



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# File 'lib/help/remote_command_handler.rb', line 210

def get_output(exec_string, push_data = nil, stdout = [], stderr = [])
  exec_string = "echo #{push_data} >tmp.txt; #{exec_string} <tmp.txt; rm -f tmp.txt" unless push_data == nil
  stdout = []
  stderr = []
  remote_exec_helper(exec_string, stdout, stderr)
  stdout.join()
end

#install(software_package) ⇒ Object

Installs the software package specified.



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# File 'lib/help/remote_command_handler.rb', line 49

def install(software_package)
  e = "yum -yq install #{software_package}"
  yum = remote_execute(e)
  if !yum
    @logger.info("yum installation failed; try apt-get")
    e = "apt-get -yq install #{software_package}"
    apt = remote_execute(e)
    @logger.info("apt=get installation? #{apt}")
  end
end

#local_rcopy(source_path, dest_path, exclude_path = nil) ⇒ Object

Copy directory using basic cp exclude_path: a space separated list of directory



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# File 'lib/help/remote_command_handler.rb', line 111

def local_rcopy(source_path, dest_path, exclude_path = nil)
  e = ""
  if exclude_path.nil? || exclude_path.empty? 
    e = "cp -Rpv #{source_path} #{dest_path}"
  else
    # only one level of exclusion
    exclusion_regexp = exclude_path.gsub(' ', '|')
    e = "for dir in $(ls -d #{source_path}* | grep -E -v '#{exclusion_regexp}'); do cp -Rpv $dir #{dest_path}; done;"
  end
  @logger.debug "going to execute #{e}"
  remote_exec_helper(e, nil, nil, false)
end

#local_rsync(source_path, dest_path, exclude_path = nil) ⇒ Object

Copy directory using options -avHx



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# File 'lib/help/remote_command_handler.rb', line 125

def local_rsync(source_path, dest_path, exclude_path = nil)
  exclude = ""
  if exclude_path != nil
    exclude = "--exclude #{exclude_path}"
  end
  e = "rsync -avHx #{exclude} #{source_path} #{dest_path}"
  @logger.debug "going to execute #{e}"
  remote_exec_helper(e, nil, nil, false) #TODO: handle output in stderr?
end

#mkdir(path) ⇒ Object 



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# File 'lib/help/remote_command_handler.rb', line 74

def mkdir(path)
  e = "mkdir #{path}"
  remote_execute(e, nil, true)
end

#mount(device, path) ⇒ Object 



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# File 'lib/help/remote_command_handler.rb', line 79

def mount(device, path)
  e = "mount #{device} #{path}"
  remote_execute(e, nil, true)
end

#remote_execute(exec_string, push_data = nil, raise_exception = false) ⇒ Object

Executes the specified #exec_string on a remote session specified. When #push_data is specified, the data will be used as input for the command and thus allow to respond in advance to commands that ask the user something. The method will return true if nothing was written into stderr, otherwise false. When #raise_exception is set, an exception will be raised instead of returning false.

Raises:

  • (Exception) 


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# File 'lib/help/remote_command_handler.rb', line 178

def remote_execute(exec_string, push_data = nil, raise_exception = false)
  #XXX: command line: echo -e 'y' | mkfs -t ext3 /dev/sdf
  exec_string = "echo #{push_data} >tmp.txt; #{exec_string} <tmp.txt; rm -f tmp.txt" unless push_data == nil
  stdout = []
  stderr = []
  result = remote_exec_helper(exec_string, stdout, stderr)
  em = "RemoteCommandHandler: #{exec_string} lead to stderr message: #{stderr.join().strip}"
  @logger.info(em) unless stderr.size == 0
  raise Exception.new(em) unless result == true || raise_exception == false
  result
end

#remote_rsync(keyfile, source_path, dest_ip, dest_path) ⇒ Object

Copy directory via an ssh-tunnel.



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# File 'lib/help/remote_command_handler.rb', line 136

def remote_rsync(keyfile, source_path, dest_ip, dest_path)
  e = "rsync -rlpgoDzq -e "+'"'+"ssh -o stricthostkeychecking=no -i #{keyfile}"+'"'+" #{source_path} root@#{dest_ip}:#{dest_path}"
  @logger.debug "going to execute #{e}"
  remote_exec_helper(e, nil, nil, false) #TODO: handle output in stderr?
end

#retrieve_os ⇒ Object

Returns the result of uname -a (Linux)



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# File 'lib/help/remote_command_handler.rb', line 44

def retrieve_os()
  get_output("uname -r").strip
end

#scp(keyfile, source_path, dest_ip, dest_path) ⇒ Object

Copy directory via an ssh-tunnel.



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# File 'lib/help/remote_command_handler.rb', line 143

def scp(keyfile, source_path, dest_ip, dest_path)
  e = "scp -Cpqr -o stricthostkeychecking=no -i #{keyfile} #{source_path} root@#{dest_ip}:#{dest_path}"
  @logger.debug "going to execute #{e}"
  remote_exec_helper(e, nil, nil, false) #TODO: handle output in stderr?
end

#stdout_contains?(exec_string, search_string = "", push_data = nil) ⇒ Boolean

Executes the specified #exec_string on a remote session specified as #ssh_session and logs the command-output into the specified #logger. When #push_data is specified, the data will be used as input for the command and thus allows to respond in advance to commands that ask the user something. If the output in stdout contains the specified #search_string, the method returns true otherwise false. Output to stderr will be logged.

Returns:

  • (Boolean) 


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# File 'lib/help/remote_command_handler.rb', line 196

def stdout_contains?(exec_string, search_string = "", push_data = nil)
  exec_string = "echo #{push_data} >tmp.txt; #{exec_string} <tmp.txt; rm -f tmp.txt" unless push_data == nil
  stdout = []
  stderr = []
  remote_exec_helper(exec_string, stdout, stderr)
  @logger.info("RemoteCommandHandler: #{exec_string} lead to stderr message: #{stderr.join().strip}") unless stderr.size == 0
  stdout.join().include?(search_string)
end

#tools_installed?(software_package) ⇒ Boolean

Checks if the software package specified is installed.

Returns:

  • (Boolean) 


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# File 'lib/help/remote_command_handler.rb', line 61

def tools_installed?(software_package)
  exec_string = "which #{software_package}"
  stdout = []
  stderr = []
  result = remote_exec_helper(exec_string, stdout, stderr)
  return result == true && stdout.size > 0
end

#umount(path) ⇒ Object

Unmount the specified path.



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# File 'lib/help/remote_command_handler.rb', line 103

def umount(path)
  exec_string = "umount #{path}"
  remote_execute(exec_string)
  !drive_mounted?(path)
end

#upload(ip, user, key_data, local_file, destination_file, timeout = 60) ⇒ Object 



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# File 'lib/help/remote_command_handler.rb', line 218

def upload(ip, user, key_data, local_file, destination_file, timeout = 60)
  Timeout::timeout(timeout) {
    Net::SCP.start(ip, user, {:key_data => [key_data], :timeout => timeout}) do |scp|
      scp.upload!(local_file, destination_file)
    end
  }
end

#zip(source_path, destination_file) ⇒ Object

Zip the complete contents of the source path into the destination file. Returns the an array with stderr output messages.



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# File 'lib/help/remote_command_handler.rb', line 151

def zip(source_path, destination_file)
  begin
    exec = "cd #{source_path}; zip -ryq #{destination_file} *"
    stderr = []
    get_output(exec, nil, nil, stderr)
    return stderr
  rescue Exception => e
    raise Exception.new("zip failed due to #{e.message}")
  end
end