pacemaker: remove node on delete (SOC-11240)

On node delete, crowbar doesn't execute pacemaker barclamp due to
default pacemaker proposal not having transitions attribute enabled
for delete. Next, pacemaker needs to remove the node from the cluster
prior to being deleted from crowbar. This change adds said feature.

chef/data_bags/crowbar/template-pacemaker.json

@@ -80,9 +80,8 @@
       "config": {
         "environment": "pacemaker-base-config",
         "mode": "full",
-        "transitions": false,
-        "transition_list": [
-        ]
+        "transitions": true,
+        "transition_list": [ "delete" ]
       }
     }
   }

crowbar_framework/app/models/pacemaker_service.rb

@@ -955,6 +955,34 @@ def prepare_stonith_attributes(role_attributes, remote_nodes, member_nodes, remo
     end
   end
 
+  def transition(inst, name, state)
+    @logger.debug("Pacemaker transition: entering: #{name} for #{state}")
+
+    if state == "delete"
+      proposal = Proposal.find_by(barclamp: @bc_name, name: inst)
+      stonith_mode = proposal["attributes"]["pacemaker"]["stonith"]["mode"]
+
+      # remove node from stonith cfg
+      proposal["attributes"]["pacemaker"]["stonith"][
+        stonith_mode]["nodes"].delete(name)
+      if proposal["attributes"]["pacemaker"]["stonith"]["per_node"]["nodes"]
+        proposal["attributes"]["pacemaker"]["stonith"][
+          "per_node"]["nodes"].delete(name)
+      end
+
+      # remove from pacemaker-cluster-member
+      proposal["deployment"]["pacemaker"]["elements"][
+        "pacemaker-cluster-member"].delete(name)
+
+      # Save and commit
+      proposal.save
+      proposal_commit(inst, in_queue: false, validate: false, validate_after_save: false)
+    end
+
+    @logger.debug("Pacemaker transition: exiting: #{name} for #{state}")
+    [200, { name: name }]
+  end
+
   private
 
   def pacemaker_node_name(node, remotes)