Add coredns prometheus health and ksm cronjob sc (#3903)

* Add coredns prometheus health and ksm cronjob sc

* Add service checks in READMEs

* Markdown for critical - coredns

coredns/README.md

@@ -46,7 +46,9 @@ The CoreDNS check does not include any events.
 
 ### Service Checks
 
-The CoreDNS check does not include any service checks.
+`coredns.prometheus.health`:
+
+Returns `CRITICAL` if the Agent cannot reach the metrics endpoints.
 
 ## Troubleshooting
 

coredns/assets/service_checks.json

@@ -1 +1,11 @@
-[]
+[
+  {
+      "agent_version": "6.11.0",
+      "integration":"coredns",
+      "check": "coredns.prometheus.health",
+      "statuses": ["ok", "critical"],
+      "groups": ["endpoint"],
+      "name": "CoreDNS prometheus health",
+      "description": "Returns `CRITICAL` if the check cannot access the metrics endpoint. Returns `OK` otherwise."
+  }
+]

kubernetes_state/README.md

@@ -53,6 +53,10 @@ Returns `OK` otherwise.
 Returns `CRITICAL` if a cluster node is in a network unavailable state.
 Returns `OK` otherwise.
 
+**kubernetes_state.cronjob.next_schedule_time**
+Returns `CRITICAL` if a cron job does not have a next scheduled time for execution.
+Returns `OK` otherwise.
+
 ## Troubleshooting
 Need help? Contact [Datadog support][6].
 

kubernetes_state/assets/service_checks.json

@@ -43,5 +43,14 @@
         "groups": ["host", "node"],
         "name": "Node Network Unavailable",
         "description": "Returns `CRITICAL` if a cluster node is in a network unavailable state. Returns `UNKNOWN` if status is unknown. Returns `OK` otherwise."
+    },
+    {
+        "agent_version": "5.6.0",
+        "integration":"kubernetes",
+        "check": "kubernetes_state.cronjob.next_schedule_time",
+        "statuses": ["ok", "unknown", "critical"],
+        "groups": ["host", "node"],
+        "name": "CronJob next scheduled time",
+        "description": "Returns `CRITICAL` if a cron job does not have a next scheduled time for execution. Returns `UNKNOWN` if the scheduled time is unknown. Returns `OK` otherwise."
     }
 ]