class Proxy::RemoteExecution::Ssh::Runners::ScriptRunner

rubocop:disable Metrics/ClassLength

Constants

DEFAULT_REFRESH_INTERVAL
EXPECTED_POWER_ACTION_MESSAGES

Attributes

execution_timeout_interval[R]

Public Class Methods

build(options, suspended_action:) click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 119
def self.build(options, suspended_action:)
  effective_user = options.fetch(:effective_user, nil)
  ssh_user = options.fetch(:ssh_user, 'root')
  effective_user_method = options.fetch(:effective_user_method, 'sudo')

  user_method = if effective_user.nil? || effective_user == ssh_user
                  NoopUserMethod.new
                elsif effective_user_method == 'sudo'
                  SudoUserMethod.new(effective_user, ssh_user,
                                     options.fetch(:secrets, {}).fetch(:effective_user_password, nil))
                elsif effective_user_method == 'dzdo'
                  DzdoUserMethod.new(effective_user, ssh_user,
                                     options.fetch(:secrets, {}).fetch(:effective_user_password, nil))
                elsif effective_user_method == 'su'
                  SuUserMethod.new(effective_user, ssh_user,
                                   options.fetch(:secrets, {}).fetch(:effective_user_password, nil))
                else
                  raise "effective_user_method '#{effective_user_method}' not supported"
                end

  new(options, user_method, suspended_action: suspended_action)
end
new(options, user_method, suspended_action: nil) click to toggle source
Calls superclass method
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 99
def initialize(options, user_method, suspended_action: nil)
  super suspended_action: suspended_action
  @host = options.fetch(:hostname)
  @script = options.fetch(:script)
  @ssh_user = options.fetch(:ssh_user, 'root')
  @ssh_port = options.fetch(:ssh_port, 22)
  @ssh_password = options.fetch(:secrets, {}).fetch(:ssh_password, nil)
  @key_passphrase = options.fetch(:secrets, {}).fetch(:key_passphrase, nil)
  @host_public_key = options.fetch(:host_public_key, nil)
  @verify_host = options.fetch(:verify_host, nil)
  @execution_timeout_interval = options.fetch(:execution_timeout_interval, nil)

  @client_private_key_file = settings.ssh_identity_key_file
  @local_working_dir = options.fetch(:local_working_dir, settings.local_working_dir)
  @remote_working_dir = options.fetch(:remote_working_dir, settings.remote_working_dir)
  @cleanup_working_dirs = options.fetch(:cleanup_working_dirs, settings.cleanup_working_dirs)
  @first_execution = options.fetch(:first_execution, false)
  @user_method = user_method
end

Public Instance Methods

close() click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 208
def close
  run_sync("rm -rf \"#{remote_command_dir}\"") if should_cleanup?
rescue StandardError => e
  publish_exception('Error when removing remote working dir', e, false)
ensure
  close_session if @session
  FileUtils.rm_rf(local_command_dir) if Dir.exist?(local_command_dir) && @cleanup_working_dirs
end
close_session() click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 199
def close_session
  @session = nil
  raise 'Control socket file does not exist' unless File.exist?(local_command_file("socket"))
  @logger.debug("Sending exit request for session #{@ssh_user}@#{@host}")
  args = ['/usr/bin/ssh', @host, "-o", "User=#{@ssh_user}", "-o", "ControlPath=#{local_command_file("socket")}", "-O", "exit"].flatten
  *, err = session(args, in_stream: false, out_stream: false)
  read_output_debug(err)
end
initialization_script() click to toggle source

the script that initiates the execution

# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 164
    def initialization_script
      su_method = @user_method.instance_of?(SuUserMethod)
      # pipe the output to tee while capturing the exit code in a file
      <<-SCRIPT.gsub(/^\s+\| /, '')
      | sh -c "(#{@user_method.cli_command_prefix}#{su_method ? "'#{@remote_script} < /dev/null '" : "#{@remote_script} < /dev/null"}; echo \\$?>#{@exit_code_path}) | /usr/bin/tee #{@output_path}
      | exit \\$(cat #{@exit_code_path})"
      SCRIPT
    end
kill() click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 180
def kill
  if @session
    run_sync("pkill -f #{remote_command_file('script')}")
  else
    logger.debug('connection closed')
  end
rescue StandardError => e
  publish_exception('Unexpected error', e, false)
end
prepare_start() click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 157
def prepare_start
  @remote_script = cp_script_to_remote
  @output_path = File.join(File.dirname(@remote_script), 'output')
  @exit_code_path = File.join(File.dirname(@remote_script), 'exit_code')
end
publish_data(data, type) click to toggle source
Calls superclass method
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 217
def publish_data(data, type)
  super(data.force_encoding('UTF-8'), type) unless @user_method.filter_password?(data)
  @user_method.on_data(data, @command_in)
end
refresh() click to toggle source
Calls superclass method
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 173
def refresh
  return if @session.nil?
  super
ensure
  check_expecting_disconnect
end
start() click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 142
def start
  Proxy::RemoteExecution::Utils.prune_known_hosts!(@host, @ssh_port, logger) if @first_execution
  prepare_start
  script = initialization_script
  logger.debug("executing script:\n#{indent_multiline(script)}")
  trigger(script)
rescue StandardError, NotImplementedError => e
  logger.error("error while initializing command #{e.class} #{e.message}:\n #{e.backtrace.join("\n")}")
  publish_exception('Error initializing command', e)
end
timeout() click to toggle source
Calls superclass method
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 190
def timeout
  @logger.debug('job timed out')
  super
end
timeout_interval() click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 195
def timeout_interval
  execution_timeout_interval
end
trigger(*args) click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 153
def trigger(*args)
  run_async(*args)
end

Private Instance Methods

available_authentication_methods() click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 412
def available_authentication_methods
  methods = %w[publickey] # Always use pubkey auth as fallback
  methods << 'gssapi-with-mic' if settings[:kerberos_auth]
  methods.unshift('password') if @ssh_password
  methods
end
check_expecting_disconnect() click to toggle source

when a remote server disconnects, it's hard to tell if it was on purpose (when calling reboot) or it's an error. When it's expected, we expect the script to produce 'restart host' as its last command output

# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 403
def check_expecting_disconnect
  last_output = @continuous_output.raw_outputs.find { |d| d['output_type'] == 'stdout' }
  return unless last_output

  if EXPECTED_POWER_ACTION_MESSAGES.any? { |message| last_output['output'] =~ /^#{message}/ }
    @expecting_disconnect = true
  end
end
cp_script_to_remote(script = @script, name = 'script') click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 352
def cp_script_to_remote(script = @script, name = 'script')
  path = remote_command_file(name)
  @logger.debug("copying script to #{path}:\n#{indent_multiline(script)}")
  upload_data(sanitize_script(script), path, 555)
end
ensure_local_directory(path) click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 343
def ensure_local_directory(path)
  if File.exist?(path)
    raise "#{path} expected to be a directory" unless File.directory?(path)
  else
    FileUtils.mkdir_p(path)
  end
  return path
end
ensure_remote_directory(path) click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 382
def ensure_remote_directory(path)
  exit_code, _output, err = run_sync("mkdir -p #{path}")
  if exit_code != 0
    raise "Unable to create directory on remote system #{path}: exit code: #{exit_code}\n #{err}"
  end
end
get_args(command, with_pty = false) click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 270
def get_args(command, with_pty = false)
  args = []
  args = [{'SSHPASS' => @key_passphrase}, '/usr/bin/sshpass', '-P', 'passphrase', '-e'] if @key_passphrase
  args = [{'SSHPASS' => @ssh_password}, '/usr/bin/sshpass', '-e'] if @ssh_password
  args += ['/usr/bin/ssh', @host, ssh_options(with_pty), command].flatten
end
indent_multiline(string) click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 224
def indent_multiline(string)
  string.lines.map { |line| "  | #{line}" }.join
end
local_command_dir() click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 327
def local_command_dir
  File.join(@local_working_dir, 'foreman-proxy', "foreman-ssh-cmd-#{@id}")
end
local_command_file(filename) click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 331
def local_command_file(filename)
  File.join(ensure_local_directory(local_command_dir), filename)
end
prepare_known_hosts() click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 319
def prepare_known_hosts
  path = local_command_file('known_hosts')
  if @host_public_key
    write_command_file_locally('known_hosts', "#{@host} #{@host_public_key}")
  end
  return path
end
read_output_debug(err_io, out_io = nil) click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 295
def read_output_debug(err_io, out_io = nil)
  stdout = ''
  debug_str = ''

  if out_io
    stdout += out_io.read until out_io.eof? rescue
    out_io.close
  end
  debug_str += err_io.read until err_io.eof? rescue
  err_io.close
  debug_str.lines.each { |line| @logger.debug(line.strip) }

  return stdout, debug_str
end
remote_command_dir() click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 335
def remote_command_dir
  File.join(@remote_working_dir, "foreman-ssh-cmd-#{id}")
end
remote_command_file(filename) click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 339
def remote_command_file(filename)
  File.join(remote_command_dir, filename)
end
run_async(command) click to toggle source

Initiates run of the remote command and yields the data when available. The yielding doesn't happen automatically, but as part of calling the `refresh` method.

# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 280
def run_async(command)
  raise 'Async command already in progress' if @started

  @started = false
  @user_method.reset
  @command_pid, @command_in, @command_out = session(get_args(command, with_pty: true), err_stream: false)
  @started = true

  return true
end
run_started?() click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 291
def run_started?
  @started && @user_method.sent_all_data?
end
run_sync(command, stdin = nil) click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 310
def run_sync(command, stdin = nil)
  pid, tx, rx, err = session(get_args(command))
  tx.puts(stdin) unless stdin.nil?
  tx.close
  stdout, stderr = read_output_debug(err, rx)
  exit_status = Process.wait2(pid)[1].exitstatus
  return exit_status, stdout, stderr
end
sanitize_script(script) click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 389
def sanitize_script(script)
  script.tr("\r", '')
end
session(args, in_stream: true, out_stream: true, err_stream: true) click to toggle source

Creates session with three pipes - one for reading and two for writing. Similar to `Open3.popen3` method but without creating a separate thread to monitor it.

# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 235
def session(args, in_stream: true, out_stream: true, err_stream: true)
  @session = true

  in_read, in_write = in_stream ? IO.pipe : '/dev/null'
  out_read, out_write = out_stream ? IO.pipe : [nil, '/dev/null']
  err_read, err_write = err_stream ? IO.pipe : [nil, '/dev/null']
  command_pid = spawn(*args, :in => in_read, :out => out_write, :err => err_write)
  in_read.close if in_stream
  out_write.close if out_stream
  err_write.close if err_stream

  return command_pid, in_write, out_read, err_read
end
settings() click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 266
def settings
  Proxy::RemoteExecution::Ssh::Plugin.settings
end
should_cleanup?() click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 228
def should_cleanup?
  @session && @cleanup_working_dirs
end
ssh_options(with_pty = false) click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 249
def ssh_options(with_pty = false)
  ssh_options = []
  ssh_options << "-tt" if with_pty
  ssh_options << "-o User=#{@ssh_user}"
  ssh_options << "-o Port=#{@ssh_port}" if @ssh_port
  ssh_options << "-o IdentityFile=#{@client_private_key_file}" if @client_private_key_file
  ssh_options << "-o IdentitiesOnly=yes"
  ssh_options << "-o StrictHostKeyChecking=no"
  ssh_options << "-o PreferredAuthentications=#{available_authentication_methods.join(',')}"
  ssh_options << "-o UserKnownHostsFile=#{prepare_known_hosts}" if @host_public_key
  ssh_options << "-o NumberOfPasswordPrompts=1"
  ssh_options << "-o LogLevel=#{settings[:ssh_log_level]}"
  ssh_options << "-o ControlMaster=auto"
  ssh_options << "-o ControlPath=#{local_command_file("socket")}"
  ssh_options << "-o ControlPersist=yes"
end
upload_data(data, path, permissions = 555) click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 358
def upload_data(data, path, permissions = 555)
  ensure_remote_directory File.dirname(path)
  # We use tee here to pipe stdin coming from ssh to a file at $path, while silencing its output
  # This is used to write to $path with elevated permissions, solutions using cat and output redirection
  # would not work, because the redirection would happen in the non-elevated shell.
  command = "tee '#{path}' >/dev/null && chmod '#{permissions}' '#{path}'"

  @logger.debug("Sending data to #{path} on remote host:\n#{data}")
  status, _out, err = run_sync(command, data)

  @logger.warn("Output on stderr while uploading #{path}:\n#{err}") unless err.empty?
  if status != 0
    raise "Unable to upload file to #{path} on remote system: exit code: #{status}"
  end

  path
end
upload_file(local_path, remote_path) click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 376
def upload_file(local_path, remote_path)
  mode = File.stat(local_path).mode.to_s(8)[-3..-1]
  @logger.debug("Uploading local file: #{local_path} as #{remote_path} with #{mode} permissions")
  upload_data(File.read(local_path), remote_path, mode)
end
write_command_file_locally(filename, content) click to toggle source
# File lib/smart_proxy_remote_execution_ssh/runners/script_runner.rb, line 393
def write_command_file_locally(filename, content)
  path = local_command_file(filename)
  ensure_local_directory(File.dirname(path))
  File.write(path, content)
  return path
end