Module: FPM::Util

Included in:
Command, Command::Validator, Package, Package::NPM
Defined in:
lib/fpm/util.rb,
lib/fpm/util/tar_writer.rb

Overview

Some utility functions

Defined Under Namespace

Classes: ExecutableNotFound, NamedPipeCannotBeCopied, ProcessFailed, TarWriter, UnsupportedSpecialFile

Instance Method Summary collapse

Instance Method Details

#ar_cmd ⇒ Object

Get an array containing the recommended ‘ar’ command for this platform and the recommended options to quickly create/append to an archive without timestamps or uids (if possible).



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# File 'lib/fpm/util.rb', line 227

def ar_cmd
  return @@ar_cmd if defined? @@ar_cmd

  @@ar_cmd_deterministic = false

  # FIXME: don't assume current directory writeable
  emptyfile = Stud::Temporary.pathname
  testarchive = Stud::Temporary.pathname
  FileUtils.touch([emptyfile])

  ["ar", "gar"].each do |ar|
    ["-qc", "-qcD"].each do |ar_create_opts|
      FileUtils.rm_f([testarchive])
      # Return this combination if it creates archives without uids or timestamps.
      # Exitstatus will be nonzero if the archive can't be created,
      # or its table of contents doesn't match the regular expression.
      # Be extra-careful about locale and timezone when matching output.
      system("#{ar} #{ar_create_opts} #{testarchive} #{emptyfile} 2>/dev/null && env TZ=UTC LANG=C LC_TIME=C #{ar} -tv #{testarchive} | grep '0/0.*1970' > /dev/null 2>&1")
      if $?.exitstatus == 0
         @@ar_cmd = [ar, ar_create_opts]
         @@ar_cmd_deterministic = true
         return @@ar_cmd
      end
    end
  end
  # If no combination of ar and options omits timestamps, fall back to default.
  @@ar_cmd = ["ar", "-qc"]
  FileUtils.rm_f([testarchive, emptyfile])
  return @@ar_cmd
end

#ar_cmd_deterministic? ⇒ Boolean

Return whether the command returned by ar_cmd can create deterministic archives

Returns:

  • (Boolean) 


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# File 'lib/fpm/util.rb', line 259

def ar_cmd_deterministic?
  ar_cmd if not defined? @@ar_cmd_deterministic
  return @@ar_cmd_deterministic
end

#copied_entries ⇒ Object

def copy_entry



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# File 'lib/fpm/util.rb', line 368

def copied_entries
  # TODO(sissel): I wonder that this entry-copy knowledge needs to be put
  # into a separate class/module. As is, calling copy_entry the same way
  # in slightly different contexts will result in weird or bad behavior.
  # What I mean is if we do:
  #   pkg = FPM::Package::Dir...
  #   pkg.output()...
  #   pkg.output()...
  # The 2nd output call will fail or behave weirdly because @copied_entries
  # is already populated. even though this is anew round of copying.
  return @copied_entries ||= {}
end

#copy_entry(src, dst, preserve = false, remove_destination = false) ⇒ Object 



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# File 'lib/fpm/util.rb', line 334

def copy_entry(src, dst, preserve=false, remove_destination=false)
  case File.ftype(src)
  when 'fifo'
    if File.respond_to?(:mkfifo)
      File.mkfifo(dst)
    elsif program_exists?("mkfifo")
      safesystem("mkfifo", dst)
    else
      raise NamedPipeCannotBeCopied("Unable to copy. Cannot find program 'mkfifo' and Ruby is missing the 'File.mkfifo' method: #{src}")
    end
  when 'socket'
    require "socket"
    # In 2019, Ruby's FileUtils added this as a way to "copy" a unix socket.
    # Reference: https://github.com/ruby/fileutils/pull/36/files
    UNIXServer.new(dst).close()
  when 'characterSpecial', 'blockSpecial'
    raise  UnsupportedSpecialFile.new("File is device which fpm doesn't know how to copy (#{File.ftype(src)}): #{src}")
  when 'directory'
    FileUtils.mkdir(dst) unless File.exist? dst
  else
    # if the file with the same dev and inode has been copied already -
    # hard link it's copy to `dst`, otherwise make an actual copy
    st = File.lstat(src)
    known_entry = copied_entries[[st.dev, st.ino]]
    if known_entry
      FileUtils.ln(known_entry, dst)
    else
      FileUtils.copy_entry(src, dst, preserve, false,
                           remove_destination)
      copied_entries[[st.dev, st.ino]] = dst
    end
  end # else...
end

#copy_metadata(source, destination) ⇒ Object 



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# File 'lib/fpm/util.rb', line 311

def copy_metadata(source, destination)
  source_stat = File::lstat(source)
  dest_stat = File::lstat(destination)

  # If this is a hard-link, there's no metadata to copy.
  # If this is a symlink, what it points to hasn't been copied yet.
  return if source_stat.ino == dest_stat.ino || dest_stat.symlink?

  File.utime(source_stat.atime, source_stat.mtime, destination)
  mode = source_stat.mode
  begin
    File.lchown(source_stat.uid, source_stat.gid, destination)
  rescue Errno::EPERM
    # clear setuid/setgid
    mode &= 01777
  end

  unless source_stat.symlink?
    File.chmod(mode, destination)
  end
end

#default_shell ⇒ Object

def program_exists?



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# File 'lib/fpm/util.rb', line 37

def default_shell
  shell = ENV["SHELL"]
  return "/bin/sh" if shell.nil? || shell.empty?
  return shell
end

#erbnew(template_code) ⇒ Object

def logger



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# File 'lib/fpm/util.rb', line 417

def erbnew(template_code)
  # In Ruby 2.6(?), Ruby changed how ERB::new is invoked.
  # First, it added keyword args like `ERB.new(..., trim_mode: "-")`
  # Later, it deprecated then removed the safe_level feature.
  # As of Ruby 3.1, warnings are printed at runtime when ERB.new is called with the old syntax.
  # Ruby 2.5 and older does not support the ERB.new keyword args.
  #
  # My tests showed:
  # * Ruby 2.3.0 through 3.0 work correctly with the old syntax.
  # * Ruby 3.1.0 and newer (at time of writing, Ruby 3.2) require the new syntax
  # Therefore, in order to support the most versions of ruby, we need to do a version check
  # to invoke ERB.new correctly and without printed warnings.
  # References: https://github.com/jordansissel/fpm/issues/1894
  # Honestly, I'm not sure if Gem::Version is correct to use in this situation, but it works.

  # on older versions of Ruby, RUBY_VERSION is a frozen string, and
  # Gem::Version.new calls String#strip! which throws an exception.
  # so we have to call String#dup to get an unfrozen copy.
  if Gem::Version.new(RUBY_VERSION.dup) < Gem::Version.new("3.1.0")
    # Ruby 3.0.x and older
    return ERB.new(template_code, nil, "-")
  else
    # Ruby 3.1.0 and newer
    return ERB.new(template_code, trim_mode: "-")
  end
end

#execmd(*args) ⇒ Object

execmd( cmd [,opts])

Execute a command as a child process. The function allows to:

  • pass environment variables to child process,

  • communicate with stdin, stdout and stderr of the child process via pipes,

  • retrieve execution’s status code.

—- EXAMPLE 1 (simple execution)

if execmd([‘which’, ‘python’]) == 0

p "Python is installed"

end

—- EXAMPLE 2 (custom environment variables)

execmd(:PYTHONPATH=>‘/home/me/foo’, [ ‘python’, ‘-m’, ‘bar’])

—- EXAMPLE 3 (communicating via stdin, stdout and stderr)

script = <<PYTHON import sys sys.stdout.write(“normal outputn”) sys.stdout.write(“narning or errorn”) PYTHON status = execmd(‘python’) do |stdin,stdout,stderr|

stdin.write(script)
stdin.close
p "STDOUT: #{stdout.read}"
p "STDERR: #{stderr.read}"

end p “STATUS: #status”

—- EXAMPLE 4 (additional options)

execmd([‘which’, ‘python’], :process=>true, :stdin=>false, :stderr=>false) do |process,stdout|

p = stdout.read.chomp
process.wait
if (x = process.exit_code) == 0
  p "PYTHON: #{p}"
else
  p "ERROR:  #{x}"
end

end

OPTIONS:

:process (default: false) -- pass process object as the first argument the to block,
:stdin   (default: true)  -- pass stdin object of the child process to the block for writting,
:stdout  (default: true)  -- pass stdout object of the child process to the block for reading,
:stderr  (default: true)  -- pass stderr object of the child process to the block for reading,



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# File 'lib/fpm/util.rb', line 97

def execmd(*args)
  i = 0
  if i < args.size
    if args[i].kind_of?(Hash)
      # args[0] may contain environment variables
      env = args[i]
      i += 1
    else
      env = Hash[]
    end
  end

  if i < args.size
    if args[i].kind_of?(Array)
      args2 = args[i]
    else
      args2 = [ args[i] ]
    end
    program = args2[0]
    i += 1
  else
    raise ArgumentError.new("missing argument: cmd")
  end

  if i < args.size
    if args[i].kind_of?(Hash)
      opts = Hash[args[i].map {|k,v| [k.to_sym, v]} ]
      i += 1
    end
  else
    opts = Hash[]
  end

  opts[:process] = false unless opts.include?(:process)
  opts[:stdin]   = true  unless opts.include?(:stdin)
  opts[:stdout]  = true  unless opts.include?(:stdout)
  opts[:stderr]  = true  unless opts.include?(:stderr)

  if !program.include?("/") and !program_in_path?(program)
    raise ExecutableNotFound.new(program)
  end

  logger.debug("Running command", :args => args2)

  stdout_r, stdout_w = IO.pipe
  stderr_r, stderr_w = IO.pipe
  stdin_r, stdin_w = IO.pipe

  pid = Process.spawn(env, *args2, :out => stdout_w, :err => stderr_w, :in => stdin_r)

  stdout_w.close; stderr_w.close
  logger.debug("Process is running", :pid => pid)
  if block_given?
    args3 = []
    args3.push(process)           if opts[:process]
    args3.push(stdin_w)           if opts[:stdin]
    args3.push(stdout_r)          if opts[:stdout]
    args3.push(stderr_r)          if opts[:stderr]

    yield(*args3)

    stdin_w.close                 if opts[:stdin] and not stdin_w.closed?
    stdout_r.close                unless stdout_r.closed?
    stderr_r.close                unless stderr_r.closed?
  else
    # If no block given (not interactive) we should close stdin_w because we
    # won't be able to give input which may cause a hang.
    stdin_w.close
    # Log both stdout and stderr as 'info' because nobody uses stderr for
    # actually reporting errors and as a result 'stderr' is a misnomer.
    logger.pipe(stdout_r => :info, stderr_r => :info)
  end

  Process.waitpid(pid)
  status = $?

  return status.exitstatus
end

#expand_pessimistic_constraints(constraint) ⇒ Object

def copied_entries



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# File 'lib/fpm/util.rb', line 381

def expand_pessimistic_constraints(constraint)
  name, op, version = constraint.split(/\s+/)

  if op == '~>'

    new_lower_constraint = "#{name} >= #{version}"

    version_components = version.split('.').collect { |v| v.to_i }

    version_prefix = version_components[0..-3].join('.')
    portion_to_work_with = version_components.last(2)

    prefix = ''
    unless version_prefix.empty?
      prefix = version_prefix + '.'
    end

    one_to_increment = portion_to_work_with[0].to_i
    incremented = one_to_increment + 1

    new_version = ''+ incremented.to_s + '.0'

    upper_version = prefix + new_version

    new_upper_constraint = "#{name} < #{upper_version}"

    return [new_lower_constraint,new_upper_constraint]
  else
    return [constraint]
  end
end

#logger ⇒ Object

def expand_pesimistic_constraints



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# File 'lib/fpm/util.rb', line 413

def logger
  @logger ||= Cabin::Channel.get
end

#program_exists?(program) ⇒ Boolean

def program_in_path

Returns:

  • (Boolean) 


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# File 'lib/fpm/util.rb', line 30

def program_exists?(program)
  # Scan path to find the executable
  # Do this to help the user get a better error message.
  return program_in_path?(program) if !program.include?("/")
  return File.executable?(program)
end

#program_in_path?(program) ⇒ Boolean

Is the given program in the system’s PATH?

Returns:

  • (Boolean) 


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# File 'lib/fpm/util.rb', line 21

def program_in_path?(program)
  # return false if path is not set
  return false unless ENV['PATH']
  # Scan path to find the executable
  # Do this to help the user get a better error message.
  envpath = ENV["PATH"].split(":")
  return envpath.select { |p| File.executable?(File.join(p, program)) }.any?
end

#safesystem(*args) ⇒ Object

Run a command safely in a way that gets reports useful errors.



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# File 'lib/fpm/util.rb', line 177

def safesystem(*args)
  # ChildProcess isn't smart enough to run a $SHELL if there's
  # spaces in the first arg and there's only 1 arg.
  if args.size == 1
    args = [ default_shell, "-c", args[0] ]
  end

  if args[0].kind_of?(Hash)
    env = args.shift()
    exit_code = execmd(env, args)
  else
    exit_code = execmd(args)
  end
  program = args[0]
  success = (exit_code == 0)

  if !success
    raise ProcessFailed.new("#{program} failed (exit code #{exit_code})" \
                            ". Full command was:#{args.inspect}")
  end
  return success
end

#safesystemout(*args) ⇒ Object

Run a command safely in a way that captures output and status.



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# File 'lib/fpm/util.rb', line 201

def safesystemout(*args)
  if args.size == 1
    args = [ ENV["SHELL"], "-c", args[0] ]
  end
  program = args[0]

  if !program.include?("/") and !program_in_path?(program)
    raise ExecutableNotFound.new(program)
  end

  stdout_r_str = nil
  exit_code = execmd(args, :stdin=>false, :stderr=>false) do |stdout|
    stdout_r_str = stdout.read
  end
  success = (exit_code == 0)

  if !success
    raise ProcessFailed.new("#{program} failed (exit code #{exit_code})" \
                            ". Full command was:#{args.inspect}")
  end
  return stdout_r_str
end

#tar_cmd ⇒ Object

Get the recommended ‘tar’ command for this platform.



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# File 'lib/fpm/util.rb', line 265

def tar_cmd
  return @@tar_cmd if defined? @@tar_cmd

  # FIXME: don't assume current directory writeable
  emptyfile = Stud::Temporary.pathname
  testarchive = Stud::Temporary.pathname

  FileUtils.touch([emptyfile])

  # Prefer tar that supports more of the features we want, stop if we find tar of our dreams
  best="tar"
  bestscore=0
  @@tar_cmd_deterministic = false
  # GNU Tar, if not the default, is usually on the path as gtar, but
  # Mac OS X 10.8 and earlier shipped it as /usr/bin/gnutar
  ["tar", "gtar", "gnutar"].each do |tar|
    opts=[]
    score=0
    ["--sort=name", "--mtime=@0"].each do |opt|
      system("#{tar} #{opt} -cf #{testarchive} #{emptyfile} > /dev/null 2>&1")
      if $?.exitstatus == 0
        opts << opt
        score += 1
      end
    end
    if score > bestscore
      best=tar
      bestscore=score
      if score == 2
        @@tar_cmd_deterministic = true
        break
      end
    end
  end
  @@tar_cmd = best
  FileUtils.rm_f([testarchive, emptyfile])

  return @@tar_cmd
end

#tar_cmd_supports_sort_names_and_set_mtime? ⇒ Boolean

Return whether the command returned by tar_cmd can create deterministic archives

Returns:

  • (Boolean) 


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# File 'lib/fpm/util.rb', line 306

def tar_cmd_supports_sort_names_and_set_mtime?
  tar_cmd if not defined? @@tar_cmd_deterministic
  return @@tar_cmd_deterministic
end