Merge pull request #9349 from chef/lcg/null

Add notify_group resource

3 files changed, 106 insertions, 1 deletions

diff --git a/lib/chef/resource/notify_group.rb b/lib/chef/resource/notify_group.rb
new file mode 100644
index 0000000000..94ca261f62
--- /dev/null
+++ b/lib/chef/resource/notify_group.rb
@@ -0,0 +1,70 @@
+#
+# Copyright:: 2019-2020, Chef Software Inc.
+#
+# 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_relative "../resource"
+require_relative "../dist"
+
+class Chef
+  class Resource
+    class NotifyGroup < Chef::Resource
+      resource_name :notify_group
+      provides :notify_group
+
+      unified_mode true
+
+      description "The notify_group resource does nothing, and always fires notifications which are set on it.  Use it to DRY blocks of notifications that are common to multiple resources, and provide a single target for other resources to notify.  Unlike most resources, its default action is :nothing."
+      introduced "15.8"
+
+      examples <<~DOC
+        Wire up a notification from a service resource to stop and start the service with a 60 second delay.
+
+        ```
+        service "crude" do
+          action [ :enable, :start ]
+        end
+
+        chef_sleep "60" do
+          action :nothing
+        end
+
+        # Example code for a hypothetical badly behaved service that requires
+        # 60 seconds between a stop and start in order to restart the service
+        # (due to race conditions, bleeding connections down, resources that only
+        # slowly unlock in the background, or other poor software behaviors that
+        # are sometimes encountered).
+        #
+        notify_group "crude_stop_and_start" do
+          notifies :stop, "service[crude]", :immediately
+          notifies :sleep, "chef_sleep[60]", :immediately
+          notifies :start, "service[crude]", :immediately
+        end
+
+        template "/etc/crude/crude.conf" do
+          source "crude.conf.erb"
+          variables node["crude"]
+          notifies :run, "notify_group[crude_stop_and_start]", :immediately
+        end
+        ```
+      DOC
+
+      action :run do
+        new_resource.updated_by_last_action(true)
+      end
+
+      default_action :nothing
+    end
+  end
+end
diff --git a/lib/chef/resources.rb b/lib/chef/resources.rb
index d0344ceb9c..70b7c88fa8 100644
--- a/lib/chef/resources.rb
+++ b/lib/chef/resources.rb
@@ -1,6 +1,6 @@
 #
 # Author:: Daniel DeLeo (<dan@chef.io>)
-# Copyright:: Copyright 2010-2019, Chef Software, Inc.
+# Copyright:: Copyright 2010-2020, Chef Software Inc.
 # License:: Apache License, Version 2.0
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -66,6 +66,7 @@ require_relative "resource/macports_package"
 require_relative "resource/macos_userdefaults"
 require_relative "resource/mdadm"
 require_relative "resource/mount"
+require_relative "resource/notify_group"
 require_relative "resource/ohai"
 require_relative "resource/ohai_hint"
 require_relative "resource/openbsd_package"
diff --git a/spec/unit/resource/notify_group_spec.rb b/spec/unit/resource/notify_group_spec.rb
new file mode 100644
index 0000000000..9f43c230ac
--- /dev/null
+++ b/spec/unit/resource/notify_group_spec.rb
@@ -0,0 +1,34 @@
+#
+# Copyright:: 2019-2020, 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 "spec_helper"
+
+describe Chef::Resource::NotifyGroup do
+  let(:node) { Chef::Node.new }
+  let(:events) { Chef::EventDispatch::Dispatcher.new }
+  let(:run_context) { Chef::RunContext.new(node, {}, events) }
+  let(:resource) { Chef::Resource::NotifyGroup.new("whatever", run_context) }
+
+  it "sets the default action as :run" do
+    expect(resource.action).to eql([:nothing])
+  end
+
+  it "is always updated" do
+    resource.run_action(:run)
+    expect(resource.updated_by_last_action?).to be true
+  end
+end