Module: FPM::Util

Extended by:
FFI::Library
Included in:
Command, Command::Validator, Package, Package::NPM
Defined in:
lib/fpm/util.rb

Overview

Some utility functions

Defined Under Namespace

Classes: ExecutableNotFound, ProcessFailed

Instance Method Summary collapse

Instance Method Details

#copied_entries ⇒ Object

def copy_entry



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# File 'lib/fpm/util.rb', line 182

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) ⇒ Object 



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# File 'lib/fpm/util.rb', line 160

def copy_entry(src, dst)
  case File.ftype(src)
  when 'fifo', 'characterSpecial', 'blockSpecial', 'socket'
    st = File.stat(src)
    rc = mknod_w(dst, st.mode, st.dev)
    raise SystemCallError.new("mknod error", FFI.errno) if rc == -1
  when 'directory'
    FileUtils.mkdir(dst) unless File.exists? 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)
      copied_entries[[st.dev, st.ino]] = dst
    end
  end # else...
end

#default_shell ⇒ Object

def program_exists?



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# File 'lib/fpm/util.rb', line 40

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

#expand_pessimistic_constraints(constraint) ⇒ Object

def copied_entries



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# File 'lib/fpm/util.rb', line 195

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 227

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

#mknod_w(path, mode, dev) ⇒ Object

wrapper around mknod ffi calls



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# File 'lib/fpm/util.rb', line 148

def mknod_w(path, mode, dev)
  rc = -1
  case %x{uname -s}.chomp
  when 'Linux'
    # bits/stat.h #define _MKNOD_VER_LINUX  0
    rc = xmknod(0, path, mode, FFI::MemoryPointer.new(dev))
  else
    rc = mknod(path, mode, dev)
  end
  rc
end

#program_exists?(program) ⇒ Boolean

def program_in_path

Returns:

  • (Boolean) 


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# File 'lib/fpm/util.rb', line 33

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 26

def program_in_path?(program)
  # 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 47

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
  program = args[0]

  if !program_exists?(program)
    raise ExecutableNotFound.new(program)
  end

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

  # Create a pair of pipes to connect the
  # invoked process to the cabin logger
  stdout_r, stdout_w = IO.pipe
  stderr_r, stderr_w = IO.pipe

  process           = ChildProcess.build(*args)
  process.io.stdout = stdout_w
  process.io.stderr = stderr_w

  process.start
  stdout_w.close; stderr_w.close
  logger.debug('Process is running', :pid => process.pid)
  # 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)

  process.wait
  success = (process.exit_code == 0)

  if !success
    raise ProcessFailed.new("#{program} failed (exit code #{process.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 88

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

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

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

  process           = ChildProcess.build(*args)
  process.io.stdout = stdout_w
  process.io.stderr = stderr_w

  process.start
  stdout_w.close; stderr_w.close
  stdout_r_str = stdout_r.read
  stdout_r.close; stderr_r.close
  logger.debug("Process is running", :pid => process.pid)

  process.wait
  success = (process.exit_code == 0)

  if !success
    raise ProcessFailed.new("#{program} failed (exit code #{process.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 125

def tar_cmd
  # Rely on gnu tar for solaris and OSX.
  case %x{uname -s}.chomp
  when "SunOS"
    return "gtar"
  when "Darwin"
    # Try running gnutar, it was renamed(??) in homebrew to 'gtar' at some point, I guess? I don't know.
    ["gnutar", "gtar"].each do |tar|
      system("#{tar} > /dev/null 2> /dev/null")
      return tar unless $?.exitstatus == 127
    end
  else
    return "tar"
  end
end

#with(value, &block) ⇒ Object

Run a block with a value. Useful in lieu of assigning variables



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# File 'lib/fpm/util.rb', line 143

def with(value, &block)
  block.call(value)
end