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 46

def connect(ip, user, key_data, timeout = 30)
  @use_sudo = false
  @ssh_session = Net::SSH.start(ip, user, :key_data => [key_data], :timeout => timeout, :verbose => :warn)
  @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 35

def connect_with_keyfile(ip, user_name, keyfile, timeout = 30)
  @use_sudo = false
  @ssh_session = Net::SSH.start(ip, user_name, :keys => [keyfile], :timeout => timeout, :verbose => :warn)
  @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 140

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

#disable_sudoers_requiretty ⇒ Object

Disable ‘Defaults requiretty’ option in sudoers file



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# File 'lib/help/remote_command_handler.rb', line 215

def disable_sudoers_requiretty()
  e = "sed -r -e \'s/^(Defaults[[:blank:]]+requiretty)$/# \\1/\' -i /etc/sudoers"
  @logger.debug "going to execute '#{e}'"
  status = remote_exec_helper(e, nil, nil, true)
  if status != true
    raise Exception.new("disabling 'requiretty' from sudoers failed with status: #{status}")
  end
end

#disconnect ⇒ Object

Disconnect the current handler



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# File 'lib/help/remote_command_handler.rb', line 53

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 157

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 169

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 278

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

#enable_sudoers_requiretty ⇒ Object

Enable ‘Defaults requiretty’ option in sudoers file



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# File 'lib/help/remote_command_handler.rb', line 225

def enable_sudoers_requiretty()
  e = "sed -r -e \'s/^#[[:blank:]]*(Defaults[[:blank:]]+requiretty)$/\\1/\' -i /etc/sudoers"
  @logger.debug "going to execute '#{e}'"
  status = remote_exec_helper(e, nil, nil, true)
  if status != true
    raise Exception.new("enabling 'requiretty' from sudoers failed with status: #{status}")
  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 58

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

#get_device_label(device) ⇒ Object

Get device label



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# File 'lib/help/remote_command_handler.rb', line 80

def get_device_label(device)
  get_output("e2label #{device}").strip
end

#get_device_label_ext(device, fs_type) ⇒ Object

Get device label



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

def get_device_label_ext(device, fs_type)
  if fs_type.eql?("xfs")
    cmd = "xfs_admin -l #{device} | sed -r -e 's/^label[[:blank:]]*=[[:blank:]]*\"(.*)\"$/\\1/'"
  else
    cmd = "e2label #{device}"
  end
  get_output(cmd).strip
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 330

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, true)
  stdout.join()
end

#get_partition_device(part) ⇒ Object

Get partition label



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

def get_partition_device(part)
  #get_output("cat /etc/mtab | grep -E '[[:blank:]]+" + "#{part}" + "[[:blank:]]+' | cut -d ' ' -f 1").strip
  get_output("mount | grep -E '[[:blank:]]+" + "#{part}" + "[[:blank:]]+' | cut -d ' ' -f 1").strip
end

#get_partition_fs_type(part) ⇒ Object

Get filesystem type



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# File 'lib/help/remote_command_handler.rb', line 115

def get_partition_fs_type(part)
  get_output("cat /etc/mtab | grep -E '[[:blank:]]+" + "#{part}" + "[[:blank:]]+' | cut -d ' ' -f 3").strip
end

#get_root_device ⇒ Object

Get root partition label



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# File 'lib/help/remote_command_handler.rb', line 68

def get_root_device()
  #get_output("cat /etc/mtab | grep -E '[[:blank:]]+\/[[:blank:]]+' | cut -d ' ' -f 1").strip
  get_output("mount | grep -E '[[:blank:]]+\/[[:blank:]]+' | cut -d ' ' -f 1").strip
end

#get_root_fs_type ⇒ Object

Get filesystem type



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# File 'lib/help/remote_command_handler.rb', line 110

def get_root_fs_type()
  get_output("cat /etc/mtab | grep -E '[[:blank:]]+\/[[:blank:]]+' | cut -d ' ' -f 3").strip
end

#install(software_package) ⇒ Object

Installs the software package specified.



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# File 'lib/help/remote_command_handler.rb', line 120

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

#is_port_open?(ip, port) ⇒ Boolean

Checks for a given IP/port if there’s a response on that port.

Returns:

  • (Boolean) 


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# File 'lib/help/remote_command_handler.rb', line 15

def is_port_open?(ip, port)
  begin
    Timeout::timeout(5) do
      begin
        s = TCPSocket.new(ip, port)
        s.close
        return true
      rescue Errno::ECONNREFUSED, Errno::EHOSTUNREACH
        return false
      end
    end
  rescue Timeout::Error
    return false
  end
end

#local_decompress_and_dump(source_filename, target_device) ⇒ Object

idecompress and a file to a device locally



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# File 'lib/help/remote_command_handler.rb', line 259

def local_decompress_and_dump(source_filename, target_device)
  e = "sh -c 'gunzip -c #{source_filename} | dd of=#{target_device}'"
  @logger.debug "going to execute #{e}" 
  status = remote_exec_helper(e, nil, nil, true)
end

#local_dump_and_compress(source_device, target_filename) ⇒ Object

dump and compress a device in a file locally



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# File 'lib/help/remote_command_handler.rb', line 252

def local_dump_and_compress(source_device, target_filename)
  e = "sh -c 'dd if=#{source_device} | gzip > #{target_filename}'"
  @logger.debug "going to execute #{e}" 
  status = remote_exec_helper(e, nil, nil, true)
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 183

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 197

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, true) #TODO: handle output in stderr?
end

#mkdir(path) ⇒ Object 



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# File 'lib/help/remote_command_handler.rb', line 146

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 151

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 294

def remote_execute(exec_string, push_data = nil, raise_exception = false)
  exec_string = "sh -c '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, true)
  #dump stdout in case of error
  if result == false
    em = "RemoteCommandHandler: #{exec_string} lead to stdout message: #{stdout.join().strip}"
    @logger.info(em) unless stdout.size == 0
  end
  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_user, dest_path) ⇒ Object 



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# File 'lib/help/remote_command_handler.rb', line 234

def remote_rsync(keyfile, source_path, dest_ip, dest_user, dest_path)
  e = "rsync -rlpgoDzq --rsh 'ssh -o stricthostkeychecking=no -i #{keyfile}' --rsync-path='sudo rsync'"+
        " #{source_path} #{dest_user}@#{dest_ip}:#{dest_path}"
  @logger.debug "going to execute #{e}"
  status = remote_exec_helper(e, nil, nil, true) #TODO: handle output in stderr?
  if status != true
    raise Exception.new("rsync bewteen source and target servers failed with status: #{status}")
  end
end

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

Rsync directory via an ssh-tunnel.



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# File 'lib/help/remote_command_handler.rb', line 208

def remote_rsync_old(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 63

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

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

Copy directory via an ssh-tunnel.



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# File 'lib/help/remote_command_handler.rb', line 245

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

#set_device_label(device, label) ⇒ Object

Set device label



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# File 'lib/help/remote_command_handler.rb', line 95

def set_device_label(device, label)
  remote_execute("e2label #{device} #{label}", nil, false)
end

#set_device_label_ext(device, label, fs_type) ⇒ Object

Set device label



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# File 'lib/help/remote_command_handler.rb', line 100

def set_device_label_ext(device, label, fs_type)
  if fs_type.eql?("xfs")
    cmd = "xfs_admin -L #{label} #{device}"
  else
    cmd = "e2label #{device} #{label}"
  end
  remote_execute(cmd, nil, false)
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 316

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 132

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 175

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 338

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 267

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