Class: ChefConfig::PathHelper

Inherits:
Object
  • Object
show all
Defined in:
lib/chef-config/path_helper.rb

Constant Summary collapse

WIN_MAX_PATH =

Maximum characters in a standard Windows path (260 including drive letter and NUL)

259
BACKSLASH = 
"\\".freeze

Class Method Summary collapse

Class Method Details

.all_homes(*args, windows: ChefUtils.windows?) ⇒ Object

See self.home. This method performs a similar operation except that it yields all the different possible values of ‘HOME’ that one could have on this platform. Hence, on windows, if HOMEDRIVEHOMEPATH and USERPROFILE are different, the provided block will be called twice. This method goes out and checks the existence of each location at the time of the call.

The return is a list of all the returned values from each block invocation or a list of paths if no block is provided.



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# File 'lib/chef-config/path_helper.rb', line 249

def self.all_homes(*args, windows: ChefUtils.windows?)
  paths = []
  paths << ENV[@@per_tool_home_environment] if defined?(@@per_tool_home_environment) && @@per_tool_home_environment && ENV[@@per_tool_home_environment]
  paths << ENV["CHEF_HOME"] if ENV["CHEF_HOME"]
  if windows
    # By default, Ruby uses the following environment variables to determine Dir.home:
    # HOME
    # HOMEDRIVE HOMEPATH
    # USERPROFILE
    # Ruby only checks to see if the variable is specified - not if the directory actually exists.
    # On Windows, HOMEDRIVE HOMEPATH can point to a different location (such as an unavailable network mounted drive)
    # while USERPROFILE points to the location where the user application settings and profile are stored.  HOME
    # is not defined as an environment variable (usually).  If the home path actually uses UNC, then the prefix is
    # HOMESHARE instead of HOMEDRIVE.
    #
    # We instead walk down the following and only include paths that actually exist.
    # HOME
    # HOMEDRIVE HOMEPATH
    # HOMESHARE HOMEPATH
    # USERPROFILE

    paths << ENV["HOME"]
    paths << ENV["HOMEDRIVE"] + ENV["HOMEPATH"] if ENV["HOMEDRIVE"] && ENV["HOMEPATH"]
    paths << ENV["HOMESHARE"] + ENV["HOMEPATH"] if ENV["HOMESHARE"] && ENV["HOMEPATH"]
    paths << ENV["USERPROFILE"]
  end
  paths << Dir.home if ENV["HOME"]

  # Depending on what environment variables we're using, the slashes can go in any which way.
  # Just change them all to / to keep things consistent.
  # Note: Maybe this is a bad idea on some unixy systems where \ might be a valid character depending on
  # the particular brand of kool-aid you consume.  This code assumes that \ and / are both
  # path separators on any system being used.
  paths = paths.map { |home_path| home_path.gsub(path_separator(windows: windows), ::File::SEPARATOR) if home_path }

  # Filter out duplicate paths and paths that don't exist.
  valid_paths = paths.select { |home_path| home_path && Dir.exist?(home_path.force_encoding("utf-8")) }
  valid_paths = valid_paths.uniq

  # Join all optional path elements at the end.
  # If a block is provided, invoke it - otherwise just return what we've got.
  joined_paths = valid_paths.map { |home_path| File.join(home_path, *args) }
  if block_given?
    joined_paths.each { |p| yield p }
  else
    joined_paths
  end
end

.canonical_path(path, add_prefix = true, windows: ChefUtils.windows?) ⇒ Object

Produces a comparable path.



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# File 'lib/chef-config/path_helper.rb', line 113

def self.canonical_path(path, add_prefix = true, windows: ChefUtils.windows?)
  # First remove extra separators and resolve any relative paths
  abs_path = File.absolute_path(path)

  if windows
    # Add the \\?\ API prefix on Windows unless add_prefix is false
    # Downcase on Windows where paths are still case-insensitive
    abs_path.gsub!(::File::SEPARATOR, path_separator(windows: windows))
    if add_prefix && abs_path !~ /^\\\\?\\/
      abs_path.insert(0, "\\\\?\\")
    end

    abs_path.downcase!
  end

  abs_path
end

.cleanpath(path, windows: ChefUtils.windows?) ⇒ String

The built in ruby Pathname#cleanpath method does not clean up forward slashes and backslashes. This is a wrapper around that which does. In general this is NOT recommended for internal use within ruby/chef since ruby does not care about forward slashes vs. backslashes, even on Windows. Where this generally matters is when being rendered to the user, or being rendered into things like the windows PATH or to commands that are being executed. In some cases it may be easier on windows to render paths to unix-style for being eventually eval’d by ruby in the future (templates being rendered with code to be consumed by ruby) where forcing unix-style forward slashes avoids the issue of needing to escape the backslashes in rendered strings. This has a boolean operator to force windows-style or non-windows style operation, where the default is determined by the underlying node value.

In general if you don’t know if you need this routine, do not use it, best practice within chef/ruby itself is not to care. Only use it to force windows or unix style when it really matters.

Parameters:

  • path (String) —

    the path to clean

  • windows (Boolean) (defaults to: ChefUtils.windows?) —

    optional flag to force to windows or unix-style

Returns:

  • (String) —

    cleaned path



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# File 'lib/chef-config/path_helper.rb', line 151

def self.cleanpath(path, windows: ChefUtils.windows?)
  path = Pathname.new(path).cleanpath.to_s
  if windows
    # ensure all forward slashes are backslashes
    path.gsub(File::SEPARATOR, path_separator(windows: windows))
  else
    # ensure all backslashes are forward slashes
    path.gsub(BACKSLASH, File::SEPARATOR)
  end
end

.dirname(path, windows: ChefUtils.windows?) ⇒ Object 



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# File 'lib/chef-config/path_helper.rb', line 29

def self.dirname(path, windows: ChefUtils.windows?)
  if windows
    # Find the first slash, not counting trailing slashes
    end_slash = path.size
    loop do
      slash = path.rindex(/[#{Regexp.escape(File::SEPARATOR)}#{Regexp.escape(path_separator(windows: windows))}]/, end_slash - 1)
      if !slash
        return end_slash == path.size ? "." : path_separator(windows: windows)
      elsif slash == end_slash - 1
        end_slash = slash
      else
        return path[0..slash - 1]
      end
    end
  else
    ::File.dirname(path)
  end
end

.escape_glob(*parts, windows: ChefUtils.windows?) ⇒ Object

Deprecated.

this method is deprecated. Please use escape_glob_dirs

Paths which may contain glob-reserved characters need to be escaped before globbing can be done. stackoverflow.com/questions/14127343



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# File 'lib/chef-config/path_helper.rb', line 190

def self.escape_glob(*parts, windows: ChefUtils.windows?)
  path = cleanpath(join(*parts, windows: windows), windows: windows)
  path.gsub(/[\\\{\}\[\]\*\?]/) { |x| "\\" + x }
end

.escape_glob_dir(*parts) ⇒ Object

This function does not switch to backslashes for windows This is because only forwardslashes should be used with dir (even for windows)



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# File 'lib/chef-config/path_helper.rb', line 197

def self.escape_glob_dir(*parts)
  path = Pathname.new(join(*parts)).cleanpath.to_s
  path.gsub(/[\\\{\}\[\]\*\?]/) { |x| "\\" + x }
end

.escapepath(path) ⇒ String

This is not just escaping for something like use in Regexps, or in globs. For the former just use Regexp.escape. For the latter, use escape_glob_dir below.

This is escaping where the path to be rendered is being put into a ruby file which will later be read back by ruby (or something similar) so we need quadruple backslashes.

In order to print:

file_cache_path "C:\\chef"

We need to convert “C:chef” to “C:\\chef” to interpolate into a string which is rendered into the output file with that line in it.

Parameters:

  • path (String) —

    the path to escape

Returns:

  • (String) —

    the escaped path



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# File 'lib/chef-config/path_helper.rb', line 178

def self.escapepath(path)
  path.gsub(BACKSLASH, BACKSLASH * 4)
end

.home(*args) ⇒ String

Retrieves the “home directory” of the current user while trying to ascertain the existence of said directory. The path returned uses / for all separators (the ruby standard format). If the home directory doesn’t exist or an error is otherwise encountered, nil is returned.

If a set of path elements is provided, they are appended as-is to the home path if the homepath exists.

If an optional block is provided, the joined path is passed to that block if the home path is valid and the result of the block is returned instead.

Home-path discovery is performed once. If a path is discovered, that value is memoized so that subsequent calls to home_dir don’t bounce around.

Parameters:

  • args (Array<String>) —

    Path components to look for under the home directory.

Returns:

  • (String)

See Also:



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# File 'lib/chef-config/path_helper.rb', line 234

def self.home(*args)
  @@home_dir ||= all_homes { |p| break p }
  if @@home_dir
    path = File.join(@@home_dir, *args)
    block_given? ? (yield path) : path
  end
end

.is_sip_path?(path, node) ⇒ Boolean

Determine if the given path is protected by macOS System Integrity Protection.

Returns:

  • (Boolean) 


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# File 'lib/chef-config/path_helper.rb', line 299

def self.is_sip_path?(path, node)
  if ChefUtils.macos?
    # @todo: parse rootless.conf for this?
    sip_paths = [
      "/System", "/bin", "/sbin", "/usr"
    ]
    sip_paths.each do |sip_path|
      ChefConfig.logger.info("#{sip_path} is a SIP path, checking if it is in the exceptions list.")
      return true if path.start_with?(sip_path)
    end
    false
  else
    false
  end
end

.join(*args, windows: ChefUtils.windows?) ⇒ Object 



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# File 'lib/chef-config/path_helper.rb', line 58

def self.join(*args, windows: ChefUtils.windows?)
  path_separator_regex = Regexp.escape(windows ? "#{File::SEPARATOR}#{BACKSLASH}" : File::SEPARATOR)
  trailing_slashes_regex = /[#{path_separator_regex}]+$/.freeze
  leading_slashes_regex = /^[#{path_separator_regex}]+/.freeze
  separator = path_separator(windows: windows)

  args.flatten!
  args.inject do |joined_path, component|
    joined_path = joined_path.sub(trailing_slashes_regex, "")
    component = component.sub(leading_slashes_regex, "")
    joined_path << "#{separator}#{component}"
    joined_path
  end
end

.path_separator(windows: ChefUtils.windows?) ⇒ Object 



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# File 'lib/chef-config/path_helper.rb', line 50

def self.path_separator(windows: ChefUtils.windows?)
  if windows
    BACKSLASH
  else
    File::SEPARATOR
  end
end

.paths_eql?(path1, path2, windows: ChefUtils.windows?) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/chef-config/path_helper.rb', line 182

def self.paths_eql?(path1, path2, windows: ChefUtils.windows?)
  canonical_path(path1, windows: windows) == canonical_path(path2, windows: windows)
end

.per_tool_home_environment=(env_var) ⇒ nil

Set the project-specific home directory environment variable.

This can be used to allow per-tool home directory aliases like $KNIFE_HOME.

Parameters:

  • Key (env_var) —

    for an environment variable to use.

Returns:

  • (nil) 


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# File 'lib/chef-config/path_helper.rb', line 212

def self.per_tool_home_environment=(env_var)
  @@per_tool_home_environment = env_var
  # Reset this in case .home was already called.
  @@home_dir = nil
end

.printable?(string) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/chef-config/path_helper.rb', line 102

def self.printable?(string)
  # returns true if string is free of non-printable characters (escape sequences)
  # this returns false for whitespace escape sequences as well, e.g. \n\t
  if /[^[:print:]]/.match?(string)
    false
  else
    true
  end
end

.relative_path_from(from, to, windows: ChefUtils.windows?) ⇒ Object 



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# File 'lib/chef-config/path_helper.rb', line 202

def self.relative_path_from(from, to, windows: ChefUtils.windows?)
  Pathname.new(cleanpath(to, windows: windows)).relative_path_from(Pathname.new(cleanpath(from, windows: windows)))
end

.split_args(line) ⇒ Object

Splits a string into an array of tokens as commands and arguments

str = ‘command with “some arguments”’ split_args(str) => [“command”, “with”, “"some arguments"”]



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# File 'lib/chef-config/path_helper.rb', line 335

def self.split_args(line)
  cmd_args = []
  field = ""
  line.scan(/\s*(?>([^\s\\"]+|"([^"]*)"|'([^']*)')|(\S))(\s|\z)?/m) do |word, within_dq, within_sq, esc, sep|

    # Append the string with Word & Escape Character
    field << (word || esc.gsub(/\\(.)/, "\\1"))

    # Re-build the field when any whitespace character or
    # End of string is encountered
    if sep
      cmd_args << field
      field = ""
    end
  end
  cmd_args
end

.validate_path(path, windows: ChefUtils.windows?) ⇒ Object 



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# File 'lib/chef-config/path_helper.rb', line 73

def self.validate_path(path, windows: ChefUtils.windows?)
  if windows
    unless printable?(path)
      msg = "Path '#{path}' contains non-printable characters. Check that backslashes are escaped with another backslash (e.g. C:\\\\Windows) in double-quoted strings."
      ChefConfig.logger.error(msg)
      raise ChefConfig::InvalidPath, msg
    end

    if windows_max_length_exceeded?(path)
      ChefConfig.logger.trace("Path '#{path}' is longer than #{WIN_MAX_PATH}, prefixing with'\\\\?\\'")
      path.insert(0, "\\\\?\\")
    end
  end

  path
end

.windows_max_length_exceeded?(path) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/chef-config/path_helper.rb', line 90

def self.windows_max_length_exceeded?(path)
  # Check to see if paths without the \\?\ prefix are over the maximum allowed length for the Windows API
  # http://msdn.microsoft.com/en-us/library/windows/desktop/aa365247%28v=vs.85%29.aspx
  unless /^\\\\?\\/.match?(path)
    if path.length > WIN_MAX_PATH
      return true
    end
  end

  false
end

.writable_sip_path?(path) ⇒ Boolean

Determine if the given path is on the exception list for macOS System Integrity Protection.

Returns:

  • (Boolean) 


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# File 'lib/chef-config/path_helper.rb', line 316

def self.writable_sip_path?(path)
  # todo: parse rootless.conf for this?
  sip_exceptions = [
    "/System/Library/Caches", "/System/Library/Extensions",
    "/System/Library/Speech", "/System/Library/User Template",
    "/usr/libexec/cups", "/usr/local", "/usr/share/man"
  ]
  sip_exceptions.each do |exception_path|
    return true if path.start_with?(exception_path)
  end
  ChefConfig.logger.error("Cannot write to a SIP path #{path} on macOS!")
  false
end