Class: Aspera::Environment

Inherits:
Object
  • Object
show all
Includes:
Singleton
Defined in:
lib/aspera/environment.rb

Overview

detect OS, architecture, and specific stuff

Constant Summary collapse

OS_WINDOWS = 
:windows
OS_MACOS = 
:osx
OS_LINUX = 
:linux
OS_AIX = 
:aix
OS_LIST = 
[OS_WINDOWS, OS_MACOS, OS_LINUX, OS_AIX].freeze
CPU_X86_64 = 
:x86_64
CPU_ARM64 = 
:arm64
CPU_PPC64 = 
:ppc64
CPU_PPC64LE = 
:ppc64le
CPU_S390 = 
:s390
CPU_LIST = 
[CPU_X86_64, CPU_ARM64, CPU_PPC64, CPU_PPC64LE, CPU_S390].freeze
BITS_PER_BYTE = 
8
MEBI = 
1024 * 1024
BYTES_PER_MEBIBIT = 
MEBI / BITS_PER_BYTE
I18N_VARS = 
%w(LC_ALL LC_CTYPE LANG).freeze
WINDOWS_FILENAME_INVALID_CHARACTERS =

“/” is invalid on both Unix and Windows, other are Windows special characters See: learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file

'<>:"/\\|?*'
REPLACE_CHARACTER = 
'_'
RB_EXT = 
'.rb'
PROCESS_MODES = 
i[execute background capture].freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Environment

Returns a new instance of Environment.



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# File 'lib/aspera/environment.rb', line 194

def initialize
  initialize_fields
end

Instance Attribute Details

#cpu ⇒ Object (readonly)

Returns the value of attribute cpu.



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# File 'lib/aspera/environment.rb', line 192

def cpu
  @cpu
end

#default_gui_mode ⇒ Object (readonly)

Returns the value of attribute default_gui_mode.



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# File 'lib/aspera/environment.rb', line 192

def default_gui_mode
  @default_gui_mode
end

#file_illegal_characters ⇒ Object

Returns the value of attribute file_illegal_characters.



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# File 'lib/aspera/environment.rb', line 191

def file_illegal_characters
  @file_illegal_characters
end

#os ⇒ Object (readonly)

Returns the value of attribute os.



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# File 'lib/aspera/environment.rb', line 192

def os
  @os
end

#url_method ⇒ Object

Returns the value of attribute url_method.



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# File 'lib/aspera/environment.rb', line 191

def url_method
  @url_method
end

Class Method Details

.build_spawn_argv(cmd, kwargs) ⇒ Object

Build argv for Process.spawn / Kernel.system (no shell)

Parameters:

  • cmd (Array) —

    Command and arguments

  • kwargs (Hash) —

    Additional arguments to secure_execute



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# File 'lib/aspera/environment.rb', line 68

def build_spawn_argv(cmd, kwargs)
  env = kwargs.delete(:env)
  argv = []
  argv << env if env
  argv << [cmd.first, cmd.first] # no shell, preserve argv[0]
  argv.concat(cmd.drop(1))
  argv
end

.empty_binding ⇒ Object

Empty variable binding for secure eval



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# File 'lib/aspera/environment.rb', line 53

def empty_binding
  return Kernel.binding
end

.force_terminal_c ⇒ Object

force locale to C so that unicode characters are not used



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# File 'lib/aspera/environment.rb', line 180

def force_terminal_c
  I18N_VARS.each{ |var| ENV[var] = 'C'}
end

.restrict_file_access(path, mode: nil) ⇒ Object

restrict access to a file or folder to user only



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# File 'lib/aspera/environment.rb', line 158

def restrict_file_access(path, mode: nil)
  if mode.nil?
    # or FileUtils ?
    if File.file?(path)
      mode = 0o600
    elsif File.directory?(path)
      mode = 0o700
    else
      Log.log.debug{"No restriction can be set for #{path}"}
    end
  end
  File.chmod(mode, path) unless mode.nil?
rescue => e
  Log.log.warn(e.message)
end

.ruby_version ⇒ Object 



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# File 'lib/aspera/environment.rb', line 48

def ruby_version
  return RbConfig::CONFIG['RUBY_PROGRAM_VERSION']
end

.secure_eval(code, file, line, user_binding = nil) ⇒ Object

Secure execution of Ruby code

Parameters:

  • code (String) —

    Ruby code to execute

  • file (String) —

    File name for error reporting

  • line (Integer) —

    Line number for error reporting



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# File 'lib/aspera/environment.rb', line 61

def secure_eval(code, file, line, user_binding = nil)
  Kernel.send('lave'.reverse, code, user_binding || empty_binding, file, line)
end

.secure_execute(*cmd, mode: :execute, **kwargs) ⇒ nil, ...

Execute a process securely without shell.

Execution mode can be:

  • :execute -> Kernel.system, return nil

  • :background -> Process.spawn, return pid

  • :capture -> Open3.capture3, return stdout

Parameters:

  • cmd (Array<String>) —

    Executable and arguments (mapped “to_s”)

  • mode (:execute, :background, :capture) (defaults to: :execute) —

    Execution mode

  • kwargs (Hash) —

    Additional arguments to underlying method

Options Hash (**kwargs):

  • :env (Hash) —

    Environment variables

  • :exception (Boolean) —

    for :capture mode, raise error if process fails

  • :close_others (Boolean) —

    for :background mode

Returns:

  • (nil) —

    for :execute mode

  • (Integer) —

    pid for :background mode

  • (String) —

    stdout for :capture mode



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# File 'lib/aspera/environment.rb', line 103

def secure_execute(*cmd, mode: :execute, **kwargs)
  cmd = cmd.map(&:to_s)
  Aspera.assert(cmd.size.positive?, type: ArgumentError){'executable must be present'}
  Aspera.assert_values(mode, PROCESS_MODES, type: ArgumentError){'mode'}
  Log.log.debug do
    parts = [mode.to_s, 'command:']
    kwargs[:env]&.each{ |k, v| parts << "#{k}=#{shell_escape_pretty(v.to_s)}"}
    cmd.each{ |a| parts << shell_escape_pretty(a)}
    parts.join(' ')
  end
  case mode
  when :execute
    # https://docs.ruby-lang.org/en/master/Kernel.html#method-i-system
    # https://docs.ruby-lang.org/en/master/Process.html#module-Process-label-Execution+Options
    kwargs[:exception] = true unless kwargs.key?(:exception)
    Kernel.system(*build_spawn_argv(cmd, kwargs), **kwargs)
  when :background
    # https://docs.ruby-lang.org/en/master/Process.html#method-c-spawn
    # https://docs.ruby-lang.org/en/master/Process.html#module-Process-label-Execution+Options
    kwargs[:close_others] = true unless kwargs.key?(:close_others)
    pid = Process.spawn(*build_spawn_argv(cmd, kwargs), **kwargs)
    Log.dump(:pid, pid)
    pid
  when :capture
    # https://docs.ruby-lang.org/en/master/Open3.html#method-c-capture3
    # https://docs.ruby-lang.org/en/master/Process.html#module-Process-label-Execution+Options
    argv = [kwargs.delete(:env)].compact + cmd
    exception = kwargs.delete(:exception){true}
    stdout, stderr, status = Open3.capture3(*argv, **kwargs)
    Log.log.debug{"status=#{status}, stderr=#{stderr}"}
    Log.log.trace1{"stdout=#{stdout}"}
    raise "Process failed: #{status.exitstatus} (#{stderr})" if exception && !status.success?
    stdout
  else Aspera.error_unreachable_line
  end
end

.shell_escape_pretty(str) ⇒ Object

like Shellwords.shellescape, but does not escape ‘=`



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# File 'lib/aspera/environment.rb', line 78

def shell_escape_pretty(str)
  # Safe unquoted characters + '=' explicitly allowed
  return str if str.match?(%r{\A[A-Za-z0-9_.,:/@+=-]+\z})
  # return str if Shellwords.shellescape(str) == str

  # Otherwise use single quotes
  "'#{str.gsub("'", %q('\'\''))}'"
end

.terminal? ⇒ Boolean

Returns true if we are in a terminal.

Returns:

  • (Boolean) —

    true if we are in a terminal



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# File 'lib/aspera/environment.rb', line 175

def terminal?
  $stdout.tty?
end

.terminal_supports_unicode? ⇒ Boolean

www.gnu.org/software/libc/manual/html_node/Locale-Categories.html pubs.opengroup.org/onlinepubs/7908799/xbd/envvar.html

Returns:

  • (Boolean) —

    true if we can display Unicode characters



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# File 'lib/aspera/environment.rb', line 187

def terminal_supports_unicode?
  terminal? && I18N_VARS.any?{ |var| ENV[var]&.include?('UTF-8')}
end

.write_file_restricted(path, force: false, mode: nil) ⇒ Object

Write content to a file, with restricted access

Parameters:

  • path (String) —

    the file path

  • force (Boolean) (defaults to: false) —

    if true, overwrite the file

  • mode (Integer) (defaults to: nil) —

    the file mode (permissions)



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# File 'lib/aspera/environment.rb', line 145

def write_file_restricted(path, force: false, mode: nil)
  Aspera.assert(block_given?, type: Aspera::InternalError)
  if force || !File.exist?(path)
    # Windows may give error
    File.unlink(path) rescue nil
    # content provided by block
    File.write(path, yield)
    restrict_file_access(path, mode: mode)
  end
  return path
end

Instance Method Details

#architecture ⇒ Object

Normalized architecture name See constants: OS_* and CPU_*



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# File 'lib/aspera/environment.rb', line 241

def architecture
  "#{@os}-#{@cpu}"
end

#exe_file(name = nil) ⇒ String

Add executable file extension (e.g. “.exe”) for current OS

Parameters:

  • name (String, nil) (defaults to: nil) —

    Path or file name

Returns:

  • (String) —

    Executable name with extension



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# File 'lib/aspera/environment.rb', line 248

def exe_file(name = nil)
  return name unless @executable_extension
  return "#{name}#{@executable_extension}"
end

#fix_home ⇒ Object

on Windows, the env var %USERPROFILE% provides the path to user’s home more reliably than %HOMEDRIVE%%HOMEPATH% so, tell Ruby the right way



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# File 'lib/aspera/environment.rb', line 255

def fix_home
  return unless @os.eql?(OS_WINDOWS) && ENV.key?('USERPROFILE') && Dir.exist?(ENV.fetch('USERPROFILE', nil))
  ENV['HOME'] = ENV.fetch('USERPROFILE', nil)
  Log.log.debug{"Windows: set HOME to USERPROFILE: #{Dir.home}"}
end

#graphical? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/aspera/environment.rb', line 261

def graphical?
  @default_gui_mode == :graphical
end

#initialize_fields ⇒ Object

initialize fields from environment



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# File 'lib/aspera/environment.rb', line 199

def initialize_fields
  @os =
    case RbConfig::CONFIG['host_os']
    when /mswin/, /msys/, /mingw/, /cygwin/, /bccwin/, /wince/, /emc/
      OS_WINDOWS
    when /darwin/, /mac os/
      OS_MACOS
    when /linux/
      OS_LINUX
    when /aix/
      OS_AIX
    else Aspera.error_unexpected_value(RbConfig::CONFIG['host_os']){'host_os'}
    end
  @cpu =
    case RbConfig::CONFIG['host_cpu']
    when /x86_64/, /x64/
      CPU_X86_64
    when /powerpc/, /ppc64/
      @os.eql?(OS_LINUX) ? CPU_PPC64LE : CPU_PPC64
    when /s390/
      CPU_S390
    when /arm/, /aarch64/
      CPU_ARM64
    else Aspera.error_unexpected_value(RbConfig::CONFIG['host_cpu']){'host_cpu'}
    end
  @executable_extension = @os.eql?(OS_WINDOWS) ? '.exe' : nil
  # :text or :graphical depending on the environment
  @default_gui_mode =
    if [Environment::OS_WINDOWS, Environment::OS_MACOS].include?(os) ||
        (ENV.key?('DISPLAY') && !ENV['DISPLAY'].empty?)
      # assume not remotely connected on macos and windows or unix family
      :graphical
    else
      :text
    end
  @url_method = @default_gui_mode
  @file_illegal_characters = REPLACE_CHARACTER + WINDOWS_FILENAME_INVALID_CHARACTERS
  nil
end

#open_editor(file_path) ⇒ Object

open a file in an editor



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# File 'lib/aspera/environment.rb', line 278

def open_editor(file_path)
  if ENV.key?('EDITOR')
    self.class.secure_execute(ENV['EDITOR'], file_path.to_s)
  elsif @os.eql?(Environment::OS_WINDOWS)
    self.class.secure_execute('notepad.exe', %Q{"#{file_path}"})
  else
    open_uri_graphical(file_path.to_s)
  end
end

#open_uri(the_url) ⇒ Object

Allows a user to open a URL if method is :text, then URL is displayed on terminal if method is :graphical, then the URL will be opened with the default browser. this is non blocking



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# File 'lib/aspera/environment.rb', line 292

def open_uri(the_url)
  case @url_method
  when :graphical
    open_uri_graphical(the_url)
  when :text
    case the_url.to_s
    when /^http/
      puts "USER ACTION: please enter this URL in a browser:\n#{the_url.to_s.red}\n"
    else
      puts "USER ACTION: open this:\n#{the_url.to_s.red}\n"
    end
  else Aspera.error_unexpected_value(@url_method){'URL open method'}
  end
end

#open_uri_graphical(uri) ⇒ Object

Open a URI in a graphical browser Command must be non blocking

Parameters:

  • uri (String) —

    the URI to open



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# File 'lib/aspera/environment.rb', line 268

def open_uri_graphical(uri)
  case @os
  when Environment::OS_MACOS then return self.class.secure_execute('open', uri.to_s)
  when Environment::OS_WINDOWS then return self.class.secure_execute('start', 'explorer', %Q{"#{uri}"})
  when Environment::OS_LINUX   then return self.class.secure_execute('xdg-open', uri.to_s)
  else Assert.error_unexpected_value(os){'no graphical open method'}
  end
end

#safe_filename_character ⇒ Object

Replacement character for illegal filename characters Can also be used as safe “join” character



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# File 'lib/aspera/environment.rb', line 309

def safe_filename_character
  return REPLACE_CHARACTER if @file_illegal_characters.nil? || @file_illegal_characters.empty?
  @file_illegal_characters[0]
end

#sanitized_filename(filename) ⇒ String

Sanitize a filename by replacing illegal characters

Parameters:

  • filename (String) —

    the original filename

Returns:

  • (String) —

    A file name safe to use on file system



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# File 'lib/aspera/environment.rb', line 317

def sanitized_filename(filename)
  safe_char = safe_filename_character
  # Windows does not allow file name:
  # - with control characters anywhere
  # - ending with space or dot
  filename = filename.gsub(/[\x00-\x1F\x7F]/, safe_char)
  filename = filename.chop while filename.end_with?(' ', '.')
  if @file_illegal_characters&.size.to_i >= 2
    # replace all illegal characters with safe_char
    filename = filename.tr(@file_illegal_characters[1..-1], safe_char)
  end
  # ensure only one safe_char is used at a time
  return filename.gsub(/#{Regexp.escape(safe_char)}+/, safe_char).chomp(safe_char)
end