Add missing comments

Change-Id: I4d59bb10b3340ae85ea8406fd238ad8843b4bc50

lib/fuel_deployment/cluster.rb

@@ -389,13 +389,14 @@ module Deployment
       end
     end
 
+    # Get the list of the skipped nodes
+    # @return [Array<Deployment::Node>]
     def skipped_nodes
       select do |node|
         node.skipped?
       end
     end
 
-
     # Get the list of the failed nodes
     # @return [Array<Deployment::Task>]
     def failed_tasks
@@ -561,6 +562,11 @@ digraph "<%= uid || 'graph' %>" {
       end.sort
     end
 
+    # Set the gracefully_stop condition for this cluster
+    # If the provided block returns "true" the cluster will
+    # stop the deployment process. This block will be validated
+    # on every node visit.
+    # @param [Proc] block
     def stop_condition(&block)
       self.gracefully_stop_mark = block
     end
@@ -586,6 +592,9 @@ digraph "<%= uid || 'graph' %>" {
       @emergency_brake
     end
 
+    # If the deployment is being gracefully stopped
+    # set the node to the skipped state so it will
+    # excluded from the deployment process.
     def gracefully_stop(node)
       if gracefully_stop? && node.ready?
         node.set_status_skipped
@@ -600,36 +609,44 @@ digraph "<%= uid || 'graph' %>" {
       @emergency_brake = true
     end
 
+    # Set the fault tolerance group setting for the cluster
+    # @param [Array<Hash>] groups
     def fault_tolerance_groups=(groups=[])
       @fault_tolerance_groups = groups.select { |group| group['node_ids'].present? }
       @fault_tolerance_groups.each { |group| group['failed_node_ids'] = [] }
       debug "Setup fault tolerance groups: #{@fault_tolerance_groups}"
     end
 
+    # Check if this node if failed for the fault tolerance group
+    # and stop the deployment if the node is failed and it sets the
+    # fault tolerance count off the limit.
+    # @param [Node] node
     def validate_fault_tolerance(node)
       return if gracefully_stop?
-
       if node.failed?
         count_tolerance_fail(node)
         gracefully_stop! if fault_tolerance_excess?
       end
     end
 
+    # Set this node to be failed in the fault tolerance groups
+    # @param [Node] node
     def count_tolerance_fail(node)
-      fault_tolerance_groups.select do |g|
-        g['node_ids'].include?(node.name)
+      fault_tolerance_groups.select do |group|
+        group['node_ids'].include?(node.name)
       end.each do |group|
-        debug "Count failed node #{node.name} for group #{group['name']}"
+        debug "Count failed node: #{node.name} for group: #{group['name']}"
         group['fault_tolerance'] -= 1
         group['node_ids'].delete(node.name)
         group['failed_node_ids'] << node.name
       end
     end
 
+    # Check if there are fault tolerance groups with the fault limit exceeded.
+    # @return [TrueClass,FalseClass]
     def fault_tolerance_excess?
       is_failed = fault_tolerance_groups.select { |group| group['fault_tolerance'] < 0 }
       return false if is_failed.empty?
-
       warn "Fault tolerance exceeded the stop conditions #{is_failed}"
       true
     end