summaryrefslogtreecommitdiff
path: root/lib/chef/provider.rb
blob: 399a26aca0cf1ecbddbb38ebc1db39639f21761b (plain)
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
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
#
# Author:: Adam Jacob (<adam@chef.io>)
# Author:: Christopher Walters (<cw@chef.io>)
# Copyright:: Copyright 2008-2016, 2009-2016 Chef Software, Inc.
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

require "chef/mixin/from_file"
require "chef/mixin/convert_to_class_name"
require "chef/mixin/enforce_ownership_and_permissions"
require "chef/mixin/why_run"
require "chef/mixin/shell_out"
require "chef/mixin/provides"
require "chef/dsl/core"
require "chef/platform/service_helpers"
require "chef/node_map"
require "forwardable"

class Chef
  class Provider
    require "chef/mixin/why_run"
    require "chef/mixin/provides"

    attr_accessor :new_resource
    attr_accessor :current_resource
    attr_accessor :run_context

    attr_reader :recipe_name
    attr_reader :cookbook_name

    include Chef::Mixin::WhyRun
    extend Chef::Mixin::Provides

    # includes the "core" DSL and not the "recipe" DSL by design
    include Chef::DSL::Core

    # supports the given resource and action (late binding)
    def self.supports?(resource, action)
      true
    end

    #--
    # TODO: this should be a reader, and the action should be passed in the
    # constructor; however, many/most subclasses override the constructor so
    # changing the arity would be a breaking change. Change this at the next
    # break, e.g., Chef 11.
    attr_accessor :action

    def initialize(new_resource, run_context)
      @new_resource = new_resource
      @action = action
      @current_resource = nil
      @run_context = run_context
      @converge_actions = nil

      @recipe_name = nil
      @cookbook_name = nil
      self.class.include_resource_dsl_module(new_resource)
    end

    def whyrun_mode?
      Chef::Config[:why_run]
    end

    def whyrun_supported?
      false
    end

    def node
      run_context && run_context.node
    end

    # Used by providers supporting embedded recipes
    def resource_collection
      run_context && run_context.resource_collection
    end

    def cookbook_name
      new_resource.cookbook_name
    end

    def check_resource_semantics!
    end

    def load_current_resource
      raise Chef::Exceptions::Override, "You must override load_current_resource in #{self}"
    end

    def define_resource_requirements
    end

    def cleanup_after_converge
    end

    def action_nothing
      Chef::Log.debug("Doing nothing for #{@new_resource}")
      true
    end

    def events
      run_context.events
    end

    def run_action(action = nil)
      @action = action unless action.nil?

      # TODO: it would be preferable to get the action to be executed in the
      # constructor...

      check_resource_semantics!

      # user-defined LWRPs may include unsafe load_current_resource methods that cannot be run in whyrun mode
      if whyrun_mode? && !whyrun_supported?
        events.resource_current_state_load_bypassed(@new_resource, @action, @current_resource)
      else
        load_current_resource
        events.resource_current_state_loaded(@new_resource, @action, @current_resource)
      end

      define_resource_requirements
      process_resource_requirements

      # user-defined providers including LWRPs may
      # not include whyrun support - if they don't support it
      # we can't execute any actions while we're running in
      # whyrun mode. Instead we 'fake' whyrun by documenting that
      # we can't execute the action.
      # in non-whyrun mode, this will still cause the action to be
      # executed normally.
      if whyrun_mode? && (!whyrun_supported? || requirements.action_blocked?(@action))
        events.resource_bypassed(@new_resource, @action, self)
      else
        send("action_#{@action}")
      end

      set_updated_status

      cleanup_after_converge
    end

    def process_resource_requirements
      requirements.run(:all_actions) unless @action == :nothing
      requirements.run(@action)
    end

    def resource_updated?
      !converge_actions.empty? || @new_resource.updated_by_last_action?
    end

    def set_updated_status
      if !resource_updated?
        events.resource_up_to_date(@new_resource, @action)
      else
        events.resource_updated(@new_resource, @action)
        new_resource.updated_by_last_action(true)
      end
    end

    def requirements
      @requirements ||= ResourceRequirements.new(@new_resource, run_context)
    end

    def converge_by(descriptions, &block)
      converge_actions.add_action(descriptions, &block)
    end

    #
    # Handle patchy convergence safely.
    #
    # - Does *not* call the block if the current_resource's properties match
    #   the properties the user specified on the resource.
    # - Calls the block if current_resource does not exist
    # - Calls the block if the user has specified any properties in the resource
    #   whose values are *different* from current_resource.
    # - Does *not* call the block if why-run is enabled (just prints out text).
    # - Prints out automatic green text saying what properties have changed.
    #
    # @param properties An optional list of property names (symbols). If not
    #   specified, `new_resource.class.state_properties` will be used.
    # @param converge_block The block to do the converging in.
    #
    # @return [Boolean] whether the block was executed.
    #
    def converge_if_changed(*properties, &converge_block)
      if !converge_block
        raise ArgumentError, "converge_if_changed must be passed a block!"
      end

      properties = new_resource.class.state_properties.map { |p| p.name } if properties.empty?
      properties = properties.map { |p| p.to_sym }
      if current_resource
        # Collect the list of modified properties
        specified_properties = properties.select { |property| new_resource.property_is_set?(property) }
        modified = specified_properties.select { |p| new_resource.send(p) != current_resource.send(p) }
        if modified.empty?
          properties_str = if new_resource.sensitive
                             specified_properties.join(", ")
                           else
                             specified_properties.map { |p| "#{p}=#{new_resource.send(p).inspect}" }.join(", ")
                           end
          Chef::Log.debug("Skipping update of #{new_resource}: has not changed any of the specified properties #{properties_str}.")
          return false
        end

        # Print the pretty green text and run the block
        property_size = modified.map { |p| p.size }.max
        modified.map! do |p|
          properties_str = if new_resource.sensitive
                             "(suppressed sensitive property)"
                           else
                             "#{new_resource.send(p).inspect} (was #{current_resource.send(p).inspect})"
                           end
          "  set #{p.to_s.ljust(property_size)} to #{properties_str}"
        end
        converge_by([ "update #{current_resource.identity}" ] + modified, &converge_block)

      else
        # The resource doesn't exist. Mark that we are *creating* this, and
        # write down any properties we are setting.
        property_size = properties.map { |p| p.size }.max
        created = properties.map do |property|
          default = " (default value)" unless new_resource.property_is_set?(property)
          properties_str = if new_resource.sensitive
                             "(suppressed sensitive property)"
                           else
                             new_resource.send(property).inspect
                           end
          "  set #{property.to_s.ljust(property_size)} to #{properties_str}#{default}"
        end

        converge_by([ "create #{new_resource.identity}" ] + created, &converge_block)
      end
      true
    end

    def self.provides(short_name, opts = {}, &block)
      Chef.provider_handler_map.set(short_name, self, opts, &block)
    end

    def self.provides?(node, resource)
      Chef::ProviderResolver.new(node, resource, :nothing).provided_by?(self)
    end

    #
    # Include attributes, public and protected methods from this Resource in
    # the provider.
    #
    # If this is set to true, delegate methods are included in the provider so
    # that you can call (for example) `attrname` and it will call
    # `new_resource.attrname`.
    #
    # The actual include does not happen until the first time the Provider
    # is instantiated (so that we don't have to worry about load order issues).
    #
    # @param include_resource_dsl [Boolean] Whether to include resource DSL or
    #   not (defaults to `false`).
    #
    def self.include_resource_dsl(include_resource_dsl)
      @include_resource_dsl = include_resource_dsl
    end

    # Create the resource DSL module that forwards resource methods to new_resource
    #
    # @api private
    def self.include_resource_dsl_module(resource)
      if @include_resource_dsl && !defined?(@included_resource_dsl_module)
        provider_class = self
        @included_resource_dsl_module = Module.new do
          extend Forwardable
          define_singleton_method(:to_s) { "forwarder module for #{provider_class}" }
          define_singleton_method(:inspect) { to_s }
          # Add a delegator for each explicit property that will get the *current* value
          # of the property by default instead of the *actual* value.
          resource.class.properties.each do |name, property|
            class_eval(<<-EOM, __FILE__, __LINE__)
              def #{name}(*args, &block)
                # If no arguments were passed, we process "get" by defaulting
                # the value to current_resource, not new_resource. This helps
                # avoid issues where resources accidentally overwrite perfectly
                # valid stuff with default values.
                if args.empty? && !block
                  if !new_resource.property_is_set?(__method__) && current_resource
                    return current_resource.public_send(__method__)
                  end
                end
                new_resource.public_send(__method__, *args, &block)
              end
            EOM
          end
          dsl_methods =
            resource.class.public_instance_methods +
            resource.class.protected_instance_methods -
            provider_class.instance_methods -
            resource.class.properties.keys
          def_delegators(:new_resource, *dsl_methods)
        end
        include @included_resource_dsl_module
      end
    end

    # Enables inline evaluation of resources in provider actions.
    #
    # Without this option, any resources declared inside the Provider are added
    # to the resource collection after the current position at the time the
    # action is executed. Because they are added to the primary resource
    # collection for the chef run, they can notify other resources outside
    # the Provider, and potentially be notified by resources outside the Provider
    # (but this is complicated by the fact that they don't exist until the
    # provider executes). In this mode, it is impossible to correctly set the
    # updated_by_last_action flag on the parent Provider resource, since it
    # executes and returns before its component resources are run.
    #
    # With this option enabled, each action creates a temporary run_context
    # with its own resource collection, evaluates the action's code in that
    # context, and then converges the resources created. If any resources
    # were updated, then this provider's new_resource will be marked updated.
    #
    # In this mode, resources created within the Provider cannot interact with
    # external resources via notifies, though notifications to other
    # resources within the Provider will work. Delayed notifications are executed
    # at the conclusion of the provider's action, *not* at the end of the
    # main chef run.
    #
    # This mode of evaluation is experimental, but is believed to be a better
    # set of tradeoffs than the append-after mode, so it will likely become
    # the default in a future major release of Chef.
    #
    def self.use_inline_resources
      extend InlineResources::ClassMethods
      include InlineResources
    end

    # Chef::Provider::InlineResources
    # Implementation of inline resource convergence for providers. See
    # Provider.use_inline_resources for a longer explanation.
    #
    # This code is restricted to a module so that it can be selectively
    # applied to providers on an opt-in basis.
    #
    # @api private
    module InlineResources

      # Create a child run_context, compile the block, and converge it.
      #
      # @api private
      def compile_and_converge_action(&block)
        old_run_context = run_context
        @run_context = run_context.create_child
        return_value = instance_eval(&block)
        Chef::Runner.new(run_context).converge
        return_value
      ensure
        if run_context.resource_collection.any? { |r| r.updated? }
          new_resource.updated_by_last_action(true)
        end
        @run_context = old_run_context
      end

      # Class methods for InlineResources. Overrides the `action` DSL method
      # with one that enables inline resource convergence.
      #
      # @api private
      module ClassMethods
        # Defines an action method on the provider, running the block to
        # compile the resources, converging them, and then checking if any
        # were updated (and updating new-resource if so)
        def action(name, &block)
          # We need the block directly in a method so that `super` works
          define_method("compile_action_#{name}", &block)
          # We try hard to use `def` because define_method doesn't show the method name in the stack.
          begin
            class_eval <<-EOM
              def action_#{name}
                compile_and_converge_action { compile_action_#{name} }
              end
            EOM
          rescue SyntaxError
            define_method("action_#{name}") { send("compile_action_#{name}") }
          end
        end
      end
    end

    protected

    def converge_actions
      @converge_actions ||= ConvergeActions.new(@new_resource, run_context, @action)
    end

    def recipe_eval(&block)
      # This block has new resource definitions within it, which
      # essentially makes it an in-line Chef run. Save our current
      # run_context and create one anew, so the new Chef run only
      # executes the embedded resources.
      #
      # TODO: timh,cw: 2010-5-14: This means that the resources within
      # this block cannot interact with resources outside, e.g.,
      # manipulating notifies.

      converge_by ("evaluate block and run any associated actions") do
        saved_run_context = run_context
        begin
          @run_context = run_context.create_child
          instance_eval(&block)
          Chef::Runner.new(run_context).converge
        ensure
          @run_context = saved_run_context
        end
      end
    end

    module DeprecatedLWRPClass
      def const_missing(class_name)
        if Chef::Provider.deprecated_constants[class_name.to_sym]
          Chef.log_deprecation("Using an LWRP provider by its name (#{class_name}) directly is no longer supported in Chef 12 and will be removed.  Use Chef::ProviderResolver.new(node, resource, action) instead.")
          Chef::Provider.deprecated_constants[class_name.to_sym]
        else
          raise NameError, "uninitialized constant Chef::Provider::#{class_name}"
        end
      end

      # @api private
      def register_deprecated_lwrp_class(provider_class, class_name)
        # Register Chef::Provider::MyProvider with deprecation warnings if you
        # try to access it
        if Chef::Provider.const_defined?(class_name, false)
          Chef::Log.warn "Chef::Provider::#{class_name} already exists!  Cannot create deprecation class for #{provider_class}"
        else
          Chef::Provider.deprecated_constants[class_name.to_sym] = provider_class
        end
      end

      def deprecated_constants
        raise "Deprecated constants should be called only on Chef::Provider" unless self == Chef::Provider
        @deprecated_constants ||= {}
      end
    end
    extend DeprecatedLWRPClass
  end
end

# Requiring things at the bottom breaks cycles
require "chef/chef_class"
require "chef/mixin/why_run"
require "chef/resource_collection"
require "chef/runner"