(QENG-7201) Vmpooler Status API QueueProcessor Optimization

Before this change we used the API /status endpoint to get specific information
on pools such as the number of ready VMs and the max.
This commit creates two new endpoints to get to that information much quicker
1) poolstat?pool= takes a comma separated list of pools to return, and will provide
the max, ready and alias values.
2) /totalrunning will calculate the total number of running VMs across all pools

lib/vmpooler/api/v1.rb

@@ -341,6 +341,71 @@ module Vmpooler
       JSON.pretty_generate(Hash[result.sort_by { |k, _v| k }])
     end
 
+    # request statistics for specific pools by passing parameter 'pool'
+    # with a coma separated list of pools we want to query ?pool=ABC,DEF
+    # returns the ready, max numbers and the aliases (if set)
+    get "#{api_prefix}/poolstat/?" do
+      content_type :json
+
+      result = {}
+
+      poolscopy = []
+
+      if params[:pool]
+        subpool = params[:pool].split(",")
+        poolscopy = pools.select do |p|
+          subpool.include?(p['name']) || (p['alias'] & subpool).any?
+        end
+      end
+
+      result[:pools] = {}
+
+      poolscopy.each do |pool|
+        result[:pools][pool['name']] = {}
+
+        max      = pool['size']
+        aka      = pool['alias']
+
+        result[:pools][pool['name']][:max] = max
+
+        if aka
+          result[:pools][pool['name']][:alias] = aka
+        end
+
+      end
+
+      # using pipelined is much faster than querying each of the pools
+      res = backend.pipelined do
+        poolscopy.each do |pool|
+          backend.scard('vmpooler__ready__' + pool['name'])
+        end
+      end
+
+      res.each_with_index { |ready, i| result[:pools][poolscopy[i]['name']][:ready] = ready }
+
+      JSON.pretty_generate(Hash[result.sort_by { |k, _v| k }])
+    end
+
+    # requests the total number of running VMs
+    get "#{api_prefix}/totalrunning/?" do
+      content_type :json
+      queue = {
+          running:   0,
+      }
+
+      # using pipelined is much faster than querying each of the pools and adding them
+      # as we get the result.
+      res = backend.pipelined do
+        pools.each do |pool|
+          backend.scard('vmpooler__running__' + pool['name'])
+        end
+      end
+
+      queue[:running] = res.inject(0){ |m, x| m+x }
+
+      JSON.pretty_generate(queue)
+    end
+
     get "#{api_prefix}/summary/?" do
       content_type :json