module Puppet::Etc
On Ruby 2.1.0 and later, Etc
returns strings in variable encoding depending on environment. The string returned will be labeled with the environment's encoding (Encoding.default_external), with one exception: If the environment encoding is 7-bit ASCII, and any individual character bit representation is equal to or greater than 128 - x80 - 0b10000000 - signifying the smallest 8-bit big-endian value, the returned string will be in BINARY encoding instead of environment encoding.
Barring that exception, the returned string will be labeled as encoding Encoding.default_external, regardless of validity or byte-width. For example, ruby will label a string containing a four-byte characters such as “u{2070E}” as EUC_KR even though EUC_KR is a two-byte width encoding.
On Ruby 2.0.x and earlier, Etc
will always return string values in BINARY, ignoring encoding altogether.
For Puppet
we specifically want UTF-8 as our input from the Etc
module - which is our input for many resource instance 'is' values. The associated 'should' value will basically always be coming from Puppet
in UTF-8 - and written to disk as UTF-8. Etc
is defined for Windows but the majority calls to it return nil and Puppet
does not use it.
That being said, we have cause to retain the original, pre-override string values. `puppet resource user` (Puppet::Resource::User.indirection.search('User', {})) uses self.instances to query for user(s) and then iterates over the results of that query again to obtain state for each user. If we've overridden the original user name and not retained the original, we've lost the ability to query the system for it later. Hence the Puppet::Etc::Passwd and Puppet::Etc::Group structs.
We only use Etc
for retrieving existing property values from the system. For setting property values, providers leverage system tools (i.e., `useradd`)
@api private
Public Class Methods
closes handle to /etc/group file
# File lib/puppet/etc.rb 51 def endgrent 52 ::Etc.endgrent 53 end
closes handle to /etc/passwd file
# File lib/puppet/etc.rb 68 def endpwent 69 ::Etc.endpwent 70 end
Etc::getgrent
returns an Etc::Group struct object On first call opens /etc/group and returns parse of first entry. Each subsquent call returns new struct the next entry or nil if EOF. Call ::endgrent
to close file.
# File lib/puppet/etc.rb 46 def getgrent 47 override_field_values_to_utf8(::Etc.getgrent) 48 end
Etc::getgrid searches /etc/group file for an entry corresponding to id. returns an Etc::Group struct corresponding to the entry or raises ArgumentError if none
# File lib/puppet/etc.rb 95 def getgrgid(id) 96 override_field_values_to_utf8(::Etc.getgrgid(id)) 97 end
Etc::getgrnam
searches /etc/group file for an entry corresponding to groupname. returns an Etc::Group struct corresponding to the entry or raises ArgumentError if none
# File lib/puppet/etc.rb 88 def getgrnam(groupname) 89 override_field_values_to_utf8(::Etc.getgrnam(groupname)) 90 end
Etc::getpwent
returns an Etc::Passwd struct object On first call opens /etc/passwd and returns parse of first entry. Each subsquent call returns new struct for the next entry or nil if EOF. Call ::endgrent
to close file.
# File lib/puppet/etc.rb 63 def getpwent 64 override_field_values_to_utf8(::Etc.getpwent) 65 end
Etc::getpwnam
searches /etc/passwd file for an entry corresponding to username. returns an Etc::Passwd struct corresponding to the entry or raises ArgumentError if none
# File lib/puppet/etc.rb 81 def getpwnam(username) 82 override_field_values_to_utf8(::Etc.getpwnam(username)) 83 end
Etc::getpwuid
searches /etc/passwd file for an entry corresponding to id. returns an Etc::Passwd struct corresponding to the entry or raises ArgumentError if none
# File lib/puppet/etc.rb 102 def getpwuid(id) 103 override_field_values_to_utf8(::Etc.getpwuid(id)) 104 end
Etc::group
returns a Ruby iterator that executes a block for each entry in the /etc/group file. The code-block is passed a Group struct. See getgrent above for more details.
# File lib/puppet/etc.rb 109 def group 110 # The implementation here duplicates the logic in https://github.com/ruby/etc/blob/master/ext/etc/etc.c#L523-L537 111 # Note that we do not call ::Etc.group directly, because we 112 # want to use our wrappers for methods like getgrent, setgrent, 113 # endgrent, etc. 114 return getgrent unless block_given? 115 116 setgrent 117 begin 118 while cur_group = getgrent #rubocop:disable Lint/AssignmentInCondition 119 yield cur_group 120 end 121 ensure 122 endgrent 123 end 124 end
effectively equivalent to IO#rewind of /etc/group
# File lib/puppet/etc.rb 56 def setgrent 57 ::Etc.setgrent 58 end
effectively equivalent to IO#rewind of /etc/passwd
# File lib/puppet/etc.rb 73 def setpwent 74 ::Etc.setpwent 75 end
Private Class Methods
Utility method for overriding the String values of a struct returned by the Etc
module to UTF-8. Structs returned by the ruby Etc
module contain members with fields of type String, Integer, or Array of Strings, so we handle these types. Otherwise ignore fields.
@api private @param [Etc::Passwd or Etc::Group struct] @return [Puppet::Etc::Passwd or Puppet::Etc::Group struct] a new struct
object with the original struct values overridden to UTF-8, if valid. For invalid values originating in UTF-8, invalid characters are replaced with '?'. For each member the struct also contains a corresponding :canonical_<member name> struct member.
# File lib/puppet/etc.rb 160 def override_field_values_to_utf8(struct) 161 return nil if struct.nil? 162 new_struct = struct.is_a?(Etc::Passwd) ? puppet_etc_passwd_class.new : puppet_etc_group_class.new 163 struct.each_pair do |member, value| 164 if value.is_a?(String) 165 new_struct["canonical_#{member}".to_sym] = value.dup 166 new_struct[member] = Puppet::Util::CharacterEncoding.override_encoding_to_utf_8(value).scrub 167 elsif value.is_a?(Array) 168 new_struct["canonical_#{member}".to_sym] = value.inject([]) { |acc, elem| acc << elem.dup } 169 new_struct[member] = value.inject([]) do |acc, elem| 170 acc << Puppet::Util::CharacterEncoding.override_encoding_to_utf_8(elem).scrub 171 end 172 else 173 new_struct["canonical_#{member}".to_sym] = value 174 new_struct[member] = value 175 end 176 end 177 new_struct 178 end
@api private Defines Puppet::Etc::Group struct class. Contains all of the original member fields of Etc::Group, and additional “canonical_” versions of these fields as well. API compatible with Etc::Group. Because Struct.new defines a new Class
object, we memoize to avoid superfluous extra Class
instantiations.
# File lib/puppet/etc.rb 144 def puppet_etc_group_class 145 @group_class ||= Struct.new(*Etc::Group.members, *Etc::Group.members.map { |member| "canonical_#{member}".to_sym }) 146 end
@api private Defines Puppet::Etc::Passwd struct class. Contains all of the original member fields of Etc::Passwd, and additional “canonical_” versions of these fields as well. API compatible with Etc::Passwd. Because Struct.new defines a new Class
object, we memoize to avoid superfluous extra Class
instantiations.
# File lib/puppet/etc.rb 134 def puppet_etc_passwd_class 135 @password_class ||= Struct.new(*Etc::Passwd.members, *Etc::Passwd.members.map { |member| "canonical_#{member}".to_sym }) 136 end