Gracefully stop for task based deployment

Instead of classic stop deployment now we stop to
process new tasks, but allow to end already running tasks.

It will give us ability to run tasks again without erasing
nodes.

Also enable task based logging

Change-Id: I23b9222ac86522c0879e5ab3c7554e554df65fcc
Implements: blueprint graceful-stop-restart-deployment

spec/unit/task_cluster_spec.rb

@@ -0,0 +1,67 @@
+#    Copyright 2016 Mirantis, 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 File.join(File.dirname(__FILE__), '../spec_helper')
+
+describe Astute::TaskCluster do
+  include SpecHelpers
+
+  subject { Astute::TaskCluster.new }
+
+  let(:node) { Astute::TaskNode.new('node_name', subject) }
+
+  describe "#hook_post_node_poll" do
+    it 'should call gracefully_stop with node' do
+      subject.expects(:gracefully_stop).with(node)
+      subject.hook_post_node_poll(node)
+    end
+  end
+
+  describe "#gracefully_stop" do
+    it 'should check if node should be stopped' do
+      subject.expects(:gracefully_stop?).returns(false)
+      subject.hook_post_node_poll(node)
+    end
+
+    it 'should check if node ready' do
+      subject.stop_condition { true }
+      node.expects(:ready?).returns(false)
+      subject.hook_post_node_poll(node)
+    end
+
+    it 'should set node status as skipped if stopped' do
+      subject.stop_condition { true }
+      node.stubs(:ready?).returns(true)
+      node.stubs(:report_node_status)
+
+      node.expects(:set_status_skipped).once
+      subject.hook_post_node_poll(node)
+    end
+
+    it 'should report new node status if stopped' do
+      subject.stop_condition { true }
+      node.stubs(:ready?).returns(true)
+      node.stubs(:set_status_skipped).once
+
+      node.expects(:report_node_status)
+      subject.hook_post_node_poll(node)
+    end
+  end
+
+  it "should able to setup stop_condition" do
+    expect(subject).to respond_to(:stop_condition)
+  end
+
+end