Add ability to get confirmation on event

Currently salt doesn't allow to get confirmation on minion upon
successfull reactor execution on event. However there can be issues with
reactor in salt 2017.7 [1] or reactor register state can fail if pillar
failed to render, so node registration confirmation maybe needed. In order
to enable this functionality add node_confirm_registration parameter to
event data with value true.

[1] saltstack/salt#47539
Change-Id: I1abc4fdf172e018dcdb48abcf61532fb51ad3660
Related-Prod: https://mirantis.jira.com/browse/PROD-21463

README.rst

@@ -108,6 +108,22 @@ Event to trigger the node classification
 
     Both actions will use the minion ID as the node_name to be updated.
 
+Confirmation of node classification
+
+    Currently salt doesn't allow to get confirmation on minion upon successfull reactor execution on event. However there can be issues
+    with reactor in salt 2017.7 (https://github.com/saltstack/salt/issues/47539) or reactor register state can fail if pillar failed
+    to render, so node registration confirmation maybe needed. In order to enable this functionality add node_confirm_registration parameter to
+    event data with value true:
+
+.. code-block:: bash
+
+    salt-call event.send 'reclass/minion/classify' "{'node_master_ip': '$config_host', 'node_ip': '${node_ip}', 'node_domain': '$node_domain', 'node_cluster': '$node_cluster', 'node_hostname': '$node_hostname', 'node_os': '$node_os', node_confirm_registration: true}"
+
+    Then on minion side execute:
+      salt-call mine.get 'salt:master' ${minion_id}_classified pillar
+
+    If true is returned than registration has passed successfully
+
 Event to trigger the node declassification
 
 .. code-block:: bash

reclass/orchestrate/reactor/node_register.sls

@@ -19,3 +19,17 @@ regenerate_all_nodes:
   - queue: True
   - require:
     - salt: classify_node_{{ node_name }}
+
+{% if node_data.get('node_confirm_registration', False) | to_bool %}
+confirm_node_classification_{{ node_name }}:
+  salt.function:
+    - tgt: 'salt:master'
+    - tgt_type: pillar
+    - name: mine.send
+    - arg:
+      - '{{ node_name }}_classified'
+      - 'mine_function=cmd.shell'
+      - 'echo true'
+    - require:
+      - salt: regenerate_all_nodes
+{% endif %}

reclass/orchestrate/reactor/node_unregister.sls

@@ -8,3 +8,15 @@ unregister_node_{{ node_name }}:
   - queue: True
   - pillar:
       node_name: {{ node_name }}
+
+{% if salt['mine.get']('salt:master', node_name + '_classified', 'pillar') %}
+confirm_node_unregistration_{{ node_name }}:
+  salt.function:
+    - tgt: 'salt:master'
+    - tgt_type: pillar
+    - name: mine.delete
+    - arg:
+      - '{{ node_name }}_classified'
+    - require:
+      - salt: unregister_node_{{ node_name }}
+{% endif %}