module Puppet::Util::POSIX

Utility methods for interacting with POSIX objects; mostly user and group

Constants

LOCALE_ENV_VARS: This is a list of environment variables that we will set when we want to override the POSIX locale
USER_ENV_VARS: This is a list of user-related environment variables that we will unset when we want to provide a pristine environment for “exec” runs

Public Instance Methods

get_posix_field(space, field, id) click to toggle source

Retrieve a field from a POSIX Etc object. The id can be either an integer or a name. This only works for users and groups. It’s also broken on some platforms, unfortunately, which is why we fall back to the other method #search_posix_field in the gid and uid methods if a sanity check fails

# File lib/puppet/util/posix.rb, line 19
def get_posix_field(space, field, id)
  raise Puppet::DevError, "Did not get id from caller" unless id

  if id.is_a?(Integer)
    if id > Puppet[:maximum_uid].to_i
      Puppet.err "Tried to get #{field} field for silly id #{id}"
      return nil
    end
    method = methodbyid(space)
  else
    method = methodbyname(space)
  end

  begin
    return Etc.send(method, id).send(field)
  rescue ArgumentError => detail
    # ignore it; we couldn't find the object
    return nil
  end
end

gid(group) click to toggle source

Get the GID of a given group, provided either a GID or a name

# File lib/puppet/util/posix.rb, line 102
def gid(group)
  begin
    group = Integer(group)
  rescue ArgumentError
    # pass
  end
  if group.is_a?(Integer)
    return nil unless name = get_posix_field(:group, :name, group)
    gid = get_posix_field(:group, :gid, name)
    check_value = gid
  else
    return nil unless gid = get_posix_field(:group, :gid, group)
    name = get_posix_field(:group, :name, gid)
    check_value = name
  end
  if check_value != group
    return search_posix_field(:group, :gid, group)
  else
    return gid
  end
end

idfield(space) click to toggle source

Determine what the field name is for users and groups.

# File lib/puppet/util/posix.rb, line 72
def idfield(space)
  case space.intern
  when :gr, :group; return :gid
  when :pw, :user, :passwd; return :uid
  else
    raise ArgumentError.new("Can only handle users and groups")
  end
end

methodbyid(space) click to toggle source

Determine what the method is to get users and groups by id

# File lib/puppet/util/posix.rb, line 82
def methodbyid(space)
  case space.intern
  when :gr, :group; return :getgrgid
  when :pw, :user, :passwd; return :getpwuid
  else
    raise ArgumentError.new("Can only handle users and groups")
  end
end

methodbyname(space) click to toggle source

Determine what the method is to get users and groups by name

# File lib/puppet/util/posix.rb, line 92
def methodbyname(space)
  case space.intern
  when :gr, :group; return :getgrnam
  when :pw, :user, :passwd; return :getpwnam
  else
    raise ArgumentError.new("Can only handle users and groups")
  end
end

search_posix_field(type, field, id) click to toggle source

A degenerate method of retrieving name/id mappings. The job of this method is to retrieve all objects of a certain type, search for a specific entry and then return a given field from that entry.

# File lib/puppet/util/posix.rb, line 43
def search_posix_field(type, field, id)
  idmethod = idfield(type)
  integer = false
  if id.is_a?(Integer)
    integer = true
    if id > Puppet[:maximum_uid].to_i
      Puppet.err "Tried to get #{field} field for silly id #{id}"
      return nil
    end
  end

  Etc.send(type) do |object|
    if integer and object.send(idmethod) == id
      return object.send(field)
    elsif object.name == id
      return object.send(field)
    end
  end

  # Apparently the group/passwd methods need to get reset; if we skip
  # this call, then new users aren't found.
  case type
  when :passwd; Etc.send(:endpwent)
  when :group; Etc.send(:endgrent)
  end
  nil
end

uid(user) click to toggle source

Get the UID of a given user, whether a UID or name is provided

# File lib/puppet/util/posix.rb, line 125
def uid(user)
  begin
    user = Integer(user)
  rescue ArgumentError
    # pass
  end
  if user.is_a?(Integer)
    return nil unless name = get_posix_field(:passwd, :name, user)
    uid = get_posix_field(:passwd, :uid, name)
    check_value = uid
  else
    return nil unless uid = get_posix_field(:passwd, :uid, user)
    name = get_posix_field(:passwd, :name, uid)
    check_value = name
  end
  if check_value != user
    return search_posix_field(:passwd, :uid, user)
  else
    return uid
  end
end