Add troubleshooting for Agent Out of Memory on K8s (#842)

* Add troubleshooting for Agent Out of Memory on K8s

* Fixup

docs/en/ingest-management/troubleshooting/troubleshooting.asciidoc

@@ -713,4 +713,21 @@ The final command will install {agent}. For example:
 sudo ./elastic-agent install --url=https://fleet-server:8220 --enrollment-token=bXktc3VwZXItc2VjcmV0LWVucm9sbWVudC10b2tlbg==
 ----
 
-After running these steps your {agents} should be able to connect with {fleet} again.
+After running these steps your {agents} should be able to connect with {fleet} again.
+
+[discrete]
+[[agent-oom-k8s]]
+== {agent} Out of Memory errors on Kubernetes
+
+In a Kubernetes environment, {agent} may be terminated with reason `OOMKilled` due to inadequate available memory.
+
+To detect the problem, run the `kubectl describe pod` command and check the results for the following content:
+
+[source,sh]
+----
+       Last State:   Terminated
+       Reason:       OOMKilled
+       Exit Code:    137
+----
+
+To resolve the problem, allocate additional memory to the agent and then restart it.