class Chef::Node::Attribute
Attribute
¶ ↑
Attribute
implements a nested key-value (Hash) and flat collection (Array) data structure supporting multiple levels of precedence, such that a given key may have multiple values internally, but will only return the highest precedence value when reading.
Constants
- COMPONENTS
List of the component attribute hashes, in order of precedence, low to high.
- DEFAULT_COMPONENTS
- ENUM_METHODS
- NIL
- OVERRIDE_COMPONENTS
Attributes
return the automatic level attribute component
return the cookbook level default attribute component
return the environment level default attribute component
return the environment level override attribute component
return the force_default
level attribute component
return the force override level attribute component
return the “normal” level attribute component
return the cookbook level override attribute component
return the role level default attribute component
return the role level override attribute component
Public Class Methods
Chef::Node::Mixin::StateTracking::new
# File lib/chef/node/attribute.rb, line 198 def initialize(normal, default, override, automatic, node = nil) @default = VividMash.new(default, self, node, :default) @env_default = VividMash.new({}, self, node, :env_default) @role_default = VividMash.new({}, self, node, :role_default) @force_default = VividMash.new({}, self, node, :force_default) @normal = VividMash.new(normal, self, node, :normal) @override = VividMash.new(override, self, node, :override) @role_override = VividMash.new({}, self, node, :role_override) @env_override = VividMash.new({}, self, node, :env_override) @force_override = VividMash.new({}, self, node, :force_override) @automatic = VividMash.new(automatic, self, node, :automatic) super(nil, self, node, :merged) end
Public Instance Methods
# File lib/chef/node/attribute.rb, line 290 def automatic=(new_data) reset @automatic = VividMash.new(new_data, self, __node__, :automatic) end
# File lib/chef/node/attribute.rb, line 423 def combined_default(*path) ret = merge_defaults(path) ret == NIL ? nil : ret end
# File lib/chef/node/attribute.rb, line 418 def combined_override(*path) ret = merge_overrides(path) ret == NIL ? nil : ret end
Debug what's going on with an attribute. args
is a path spec to the attribute you're interested in. For example, to debug where the value of `node[:default_interface]` is coming from, use:
debug_value(:network, :default_interface).
The return value is an Array of Arrays. The Arrays are pairs of `[“precedence_level”, value]`, where precedence level is the component, such as role default, normal, etc. and value is the attribute value set at that precedence level. If there is no value at that precedence level, value
will be the symbol :not_present
.
# File lib/chef/node/attribute.rb, line 225 def debug_value(*args) COMPONENTS.map do |component| value = begin instance_variable_get(component).read!(*args) rescue :not_present end [component.to_s.sub(/^@/, ""), value] end end
sets default attributes without merging
-
this API autovivifies (and cannot trainwreck)
# File lib/chef/node/attribute.rb, line 363 def default!(*args) return Decorator::Unchain.new(self, :default!) unless args.length > 0 write(:default, *args) end
Set the cookbook level default attribute component to new_data
.
# File lib/chef/node/attribute.rb, line 238 def default=(new_data) reset @default = VividMash.new(new_data, self, __node__, :default) end
# File lib/chef/node/attribute.rb, line 434 def default_unless(*args) return Decorator::Unchain.new(self, :default_unless) unless args.length > 0 write(:default, *args) if default.read(*args[0...-1]).nil? end
Set the environment level default attribute component to new_data
# File lib/chef/node/attribute.rb, line 250 def env_default=(new_data) reset @env_default = VividMash.new(new_data, self, __node__, :env_default) end
Set the environment level override attribute component to new_data
# File lib/chef/node/attribute.rb, line 280 def env_override=(new_data) reset @env_override = VividMash.new(new_data, self, __node__, :env_override) end
# File lib/chef/node/attribute.rb, line 464 def exist?(*path) merged_attributes.exist?(*path) end
clears from all default precedence levels and then sets force_default
-
this API autovivifies (and cannot trainwreck)
# File lib/chef/node/attribute.rb, line 390 def force_default!(*args) return Decorator::Unchain.new(self, :force_default!) unless args.length > 0 value = args.pop rm_default(*args) write(:force_default, *args, value) end
Set the force_default
(default!
) level attributes to new_data
# File lib/chef/node/attribute.rb, line 256 def force_default=(new_data) reset @force_default = VividMash.new(new_data, self, __node__, :force_default) end
clears from all override precedence levels and then sets force_override
# File lib/chef/node/attribute.rb, line 399 def force_override!(*args) return Decorator::Unchain.new(self, :force_override!) unless args.length > 0 value = args.pop rm_override(*args) write(:force_override, *args, value) end
# File lib/chef/node/attribute.rb, line 285 def force_override=(new_data) reset @force_override = VividMash.new(new_data, self, __node__, :force_override) end
# File lib/chef/node/attribute.rb, line 446 def has_key?(key) COMPONENTS.any? do |component_ivar| instance_variable_get(component_ivar).key?(key) end end
# File lib/chef/node/attribute.rb, line 495 def inspect "#<#{self.class} " << (COMPONENTS + %i{@merged_attributes @properties}).map do |iv| "#{iv}=#{instance_variable_get(iv).inspect}" end.join(", ") << ">" end
Accessing merged attributes.
Note that merged_attributes
('foo', 'bar', 'baz') can be called to compute only the deep merge of node['bar’], but in practice we currently always compute all of node even if the user only requires node['bar’].
# File lib/chef/node/attribute.rb, line 414 def merged_attributes(*path) merge_all(path) end
sets normal attributes without merging
-
this API autovivifies (and cannot trainwreck)
# File lib/chef/node/attribute.rb, line 372 def normal!(*args) return Decorator::Unchain.new(self, :normal!) unless args.length > 0 write(:normal, *args) end
Set the normal level attribute component to new_data
# File lib/chef/node/attribute.rb, line 262 def normal=(new_data) reset @normal = VividMash.new(new_data, self, __node__, :normal) end
# File lib/chef/node/attribute.rb, line 428 def normal_unless(*args) return Decorator::Unchain.new(self, :normal_unless) unless args.length > 0 write(:normal, *args) if normal.read(*args[0...-1]).nil? end
sets override attributes without merging
-
this API autovivifies (and cannot trainwreck)
# File lib/chef/node/attribute.rb, line 381 def override!(*args) return Decorator::Unchain.new(self, :override!) unless args.length > 0 write(:override, *args) end
Set the cookbook level override attribute component to new_data
# File lib/chef/node/attribute.rb, line 268 def override=(new_data) reset @override = VividMash.new(new_data, self, __node__, :override) end
# File lib/chef/node/attribute.rb, line 440 def override_unless(*args) return Decorator::Unchain.new(self, :override_unless) unless args.length > 0 write(:override, *args) if override.read(*args[0...-1]).nil? end
method-style access to attributes (has to come after the prepended ImmutablizeHash)
# File lib/chef/node/attribute.rb, line 454 def read(*path) merged_attributes.read(*path) end
# File lib/chef/node/attribute.rb, line 460 def read!(*path) merged_attributes.read!(*path) end
clears attributes from all precedence levels
# File lib/chef/node/attribute.rb, line 300 def rm(*args) with_deep_merged_return_value(self, *args) do rm_default(*args) rm_normal(*args) rm_override(*args) end end
clears attributes from all default precedence levels
similar to: force_default!['bar'].delete('baz')
-
does not autovivify
-
does not trainwreck if interior keys do not exist
# File lib/chef/node/attribute.rb, line 313 def rm_default(*args) with_deep_merged_return_value(combined_default, *args) do default.unlink(*args) role_default.unlink(*args) env_default.unlink(*args) force_default.unlink(*args) end end
clears attributes from normal precedence
equivalent to: normal!['bar'].delete('baz')
-
does not autovivify
-
does not trainwreck if interior keys do not exist
# File lib/chef/node/attribute.rb, line 327 def rm_normal(*args) normal.unlink(*args) end
clears attributes from all override precedence levels
equivalent to: force_override!['bar'].delete('baz')
-
does not autovivify
-
does not trainwreck if interior keys do not exist
# File lib/chef/node/attribute.rb, line 336 def rm_override(*args) with_deep_merged_return_value(combined_override, *args) do override.unlink(*args) role_override.unlink(*args) env_override.unlink(*args) force_override.unlink(*args) end end
Set the role level default attribute component to new_data
# File lib/chef/node/attribute.rb, line 244 def role_default=(new_data) reset @role_default = VividMash.new(new_data, self, __node__, :role_default) end
Set the role level override attribute component to new_data
# File lib/chef/node/attribute.rb, line 274 def role_override=(new_data) reset @role_override = VividMash.new(new_data, self, __node__, :role_override) end
# File lib/chef/node/attribute.rb, line 491 def to_s merged_attributes.to_s end
# File lib/chef/node/attribute.rb, line 476 def unlink(level, *path) send(level).unlink(*path) end
# File lib/chef/node/attribute.rb, line 480 def unlink!(level, *path) send(level).unlink!(*path) end
# File lib/chef/node/attribute.rb, line 468 def write(level, *args, &block) send(level).write(*args, &block) end
# File lib/chef/node/attribute.rb, line 472 def write!(level, *args, &block) send(level).write!(*args, &block) end
Private Instance Methods
Helper method for merge_all/merge_defaults/merge_overrides.
apply_path
(thing, [ “foo”, “bar”, “baz” ]) = thing[“bar”]
The path value can be nil in which case the whole component is returned.
It returns nil (does not raise an exception) if it walks off the end of an Mash/Hash/Array, it does not raise any TypeError if it attempts to apply a hash key to an Integer/String/TrueClass, and just returns nil in that case.
# File lib/chef/node/attribute.rb, line 513 def apply_path(component, path) path ||= [] path.inject(component) do |val, path_arg| if val.respond_to?(:[]) # Have an Array-like or Hash-like thing if !val.respond_to?(:has_key?) # Have an Array-like thing val[path_arg] elsif val.key?(path_arg) # Hash-like thing (must check has_key? first to protect against Autovivification) val[path_arg] else NIL end else NIL end end end
needed for __path__
# File lib/chef/node/attribute.rb, line 588 def convert_key(key) key.is_a?(Symbol) ? key.to_s : key end
@api private
# File lib/chef/node/attribute.rb, line 595 def deep_merge!(merge_onto, merge_with) # If there are two Hashes, recursively merge. if merge_onto.is_a?(Hash) && merge_with.is_a?(Hash) merge_with.each do |key, merge_with_value| value = if merge_onto.key?(key) deep_merge!(safe_dup(merge_onto.internal_get(key)), merge_with_value) else merge_with_value end # internal_set bypasses converting keys, does convert values and allows writing to immutable mashes merge_onto.internal_set(key, value) end merge_onto elsif merge_onto.is_a?(Array) && merge_with.is_a?(Array) merge_onto |= merge_with # If merge_with is NIL, don't replace merge_onto elsif merge_with == NIL merge_onto # In all other cases, replace merge_onto with merge_with else if merge_with.is_a?(Hash) Chef::Node::ImmutableMash.new(merge_with) elsif merge_with.is_a?(Array) Chef::Node::ImmutableArray.new(merge_with) else merge_with end end end
@api private
# File lib/chef/node/attribute.rb, line 631 def hash_only_merge!(merge_onto, merge_with) # If there are two Hashes, recursively merge. if merge_onto.is_a?(Hash) && merge_with.is_a?(Hash) merge_with.each do |key, merge_with_value| value = if merge_onto.key?(key) hash_only_merge!(safe_dup(merge_onto.internal_get(key)), merge_with_value) else merge_with_value end # internal_set bypasses converting keys, does convert values and allows writing to immutable mashes merge_onto.internal_set(key, value) end merge_onto # If merge_with is NIL, don't replace merge_onto elsif merge_with == NIL merge_onto # In all other cases, replace merge_onto with merge_with else if merge_with.is_a?(Hash) Chef::Node::ImmutableMash.new(merge_with) elsif merge_with.is_a?(Array) Chef::Node::ImmutableArray.new(merge_with) else merge_with end end end
Deep merge all attribute levels using hash-only merging between different precedence levels (so override arrays completely replace arrays set at any default level).
The path allows for selectively deep-merging a subtree of the node object.
@param path [Array] Array of args to method chain to descend into the node object @return [attr] Deep Merged values (may be VividMash
, Hash, Array, etc) from the node object
# File lib/chef/node/attribute.rb, line 547 def merge_all(path) components = [ merge_defaults(path), apply_path(@normal, path), merge_overrides(path), apply_path(@automatic, path), ] ret = components.inject(NIL) do |merged, component| hash_only_merge!(merged, component) end ret == NIL ? nil : ret end
Deep merge the default attribute levels with array merging.
The path allows for selectively deep-merging a subtree of the node object.
@param path [Array] Array of args to method chain to descend into the node object @return [attr] Deep Merged values (may be VividMash
, Hash, Array, etc) from the node object
# File lib/chef/node/attribute.rb, line 567 def merge_defaults(path) DEFAULT_COMPONENTS.inject(NIL) do |merged, component_ivar| component_value = apply_path(instance_variable_get(component_ivar), path) deep_merge!(merged, component_value) end end
Deep merge the override attribute levels with array merging.
The path allows for selectively deep-merging a subtree of the node object.
@param path [Array] Array of args to method chain to descend into the node object @return [attr] Deep Merged values (may be VividMash
, Hash, Array, etc) from the node object
# File lib/chef/node/attribute.rb, line 580 def merge_overrides(path) OVERRIDE_COMPONENTS.inject(NIL) do |merged, component_ivar| component_value = apply_path(instance_variable_get(component_ivar), path) deep_merge!(merged, component_value) end end
For elements like Fixnums, true, nil…
# File lib/chef/node/attribute.rb, line 534 def safe_dup(e) e.dup rescue TypeError e end
# File lib/chef/node/attribute.rb, line 345 def with_deep_merged_return_value(obj, *path, last) hash = obj.read(*path) return nil unless hash.is_a?(Hash) ret = hash[last] yield ret end