correct service node category

- service node should be placed into "Service" category on dashboard

Change-Id: I3fac52f362523b82c7bed0ec79594685535cec9f

health_monitor/lib/health_monitor/events/heartbeat.rb

@@ -4,6 +4,10 @@ class Heartbeat < Base
 
       CORE_JOBS = Set.new(%w(cloud_controller dea health_manager nats router stager vcap_redis))
 
+      SERVICE_JOBS_PREFIXES = %w(mysql mongodb redis rabbit postgresql vblob).join("|")
+      SERVICE_JOBS_GATEWAY_REGEX = /(#{SERVICE_JOBS_PREFIXES})_gateway$/i
+      SERVICE_JOBS_NODE_REGEX = /(#{SERVICE_JOBS_PREFIXES})_node(.*)/i
+
       SERVICE_AUXILIARY_JOBS = Set.new(%w(serialization_data_server backup_manager))
 
       attr_reader :metrics
@@ -109,7 +113,18 @@ def guess_role
 
         return "service" if SERVICE_AUXILIARY_JOBS.include?(@job.to_s.downcase)
 
-        if @job.to_s =~ /(_node$|_gateway$|service)/i
+        # job name prefixed by "service"
+        if @job.to_s.downcase =~ /^service/i
+          return "service"
+        end
+
+        # job name suffixed by "_gateway"
+        if @job.to_s.downcase =~ SERVICE_JOBS_GATEWAY_REGEX
+          return "service"
+        end
+
+        # job name contains "_node"
+        if @job.to_s.downcase =~ SERVICE_JOBS_NODE_REGEX
           return "service"
         end