Added query for node warmup before reporing it's down

_data/rules.yml

@@ -26,6 +26,10 @@ groups:
               description: A Prometheus job does not have living target anymore.
               query: 'sum by (job) (up) == 0'
               severity: critical
+            - name: Prometheus target missing with warmup time
+              description: Allow a job time to start up (10 minutes) before alerting that it's down. 
+              query: 'sum by (instance, job) ((up == 0) * on (instance) group_right(job) (node_time_seconds - node_boot_time_seconds > 600))'
+              severity: critical
             - name: Prometheus configuration reload failure
               description: Prometheus configuration reload error
               query: 'prometheus_config_last_reload_successful != 1'