1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
|
# Provides feature definitions.
require 'puppet/util/methodhelper'
require 'puppet/util/docs'
require 'puppet/util'
module Puppet::Util::ProviderFeatures
include Puppet::Util::Docs
# The class that models the features and handles checking whether the features
# are present.
class ProviderFeature
include Puppet::Util
include Puppet::Util::MethodHelper
include Puppet::Util::Docs
attr_accessor :name, :docs, :methods
# Are all of the requirements met?
def available?(obj)
if self.methods
return !!methods_available?(obj)
else
# In this case, the provider has to declare support for this
# feature, and that's been checked before we ever get to the
# method checks.
return false
end
end
def initialize(name, docs, hash)
self.name = symbolize(name)
self.docs = docs
hash = symbolize_options(hash)
set_options(hash)
end
private
# Are all of the required methods available?
def methods_available?(obj)
methods.each do |m|
if obj.is_a?(Class)
return false unless obj.public_method_defined?(m)
else
return false unless obj.respond_to?(m)
end
end
true
end
end
# Define one or more features. At a minimum, features require a name
# and docs, and at this point they should also specify a list of methods
# required to determine if the feature is present.
def feature(name, docs, hash = {})
@features ||= {}
raise(Puppet::DevError, "Feature #{name} is already defined") if @features.include?(name)
begin
obj = ProviderFeature.new(name, docs, hash)
@features[obj.name] = obj
rescue ArgumentError => detail
error = ArgumentError.new(
"Could not create feature #{name}: #{detail}"
)
error.set_backtrace(detail.backtrace)
raise error
end
end
# Return a hash of all feature documentation.
def featuredocs
str = ""
@features ||= {}
return nil if @features.empty?
names = @features.keys.sort { |a,b| a.to_s <=> b.to_s }
names.each do |name|
doc = @features[name].docs.gsub(/\n\s+/, " ")
str += "- *#{name}*: #{doc}\n"
end
if providers.length > 0
headers = ["Provider", names].flatten
data = {}
providers.each do |provname|
data[provname] = []
prov = provider(provname)
names.each do |name|
if prov.feature?(name)
data[provname] << "*X*"
else
data[provname] << ""
end
end
end
str += doctable(headers, data)
end
str
end
# Return a list of features.
def features
@features ||= {}
@features.keys
end
# Generate a module that sets up the boolean methods to test for given
# features.
def feature_module
unless defined?(@feature_module)
@features ||= {}
@feature_module = ::Module.new
const_set("FeatureModule", @feature_module)
features = @features
# Create a feature? method that can be passed a feature name and
# determine if the feature is present.
@feature_module.send(:define_method, :feature?) do |name|
method = name.to_s + "?"
return !!(respond_to?(method) and send(method))
end
# Create a method that will list all functional features.
@feature_module.send(:define_method, :features) do
return false unless defined?(features)
features.keys.find_all { |n| feature?(n) }.sort { |a,b|
a.to_s <=> b.to_s
}
end
# Create a method that will determine if a provided list of
# features are satisfied by the curred provider.
@feature_module.send(:define_method, :satisfies?) do |*needed|
ret = true
needed.flatten.each do |feature|
unless feature?(feature)
ret = false
break
end
end
ret
end
# Create a boolean method for each feature so you can test them
# individually as you might need.
@features.each do |name, feature|
method = name.to_s + "?"
@feature_module.send(:define_method, method) do
(is_a?(Class) ? declared_feature?(name) : self.class.declared_feature?(name)) or feature.available?(self)
end
end
# Allow the provider to declare that it has a given feature.
@feature_module.send(:define_method, :has_features) do |*names|
@declared_features ||= []
names.each do |name|
name = symbolize(name)
@declared_features << name
end
end
# Aaah, grammatical correctness
@feature_module.send(:alias_method, :has_feature, :has_features)
end
@feature_module
end
# Return the actual provider feature instance. Really only used for testing.
def provider_feature(name)
return nil unless defined?(@features)
@features[name]
end
end
|
