Merge pull request #48228 from pegasas/issues/47823

[SidecarContainer] provide sidecar best practices hints about exit code

Author: k8s-ci-robot

content/en/docs/concepts/workloads/pods/sidecar-containers.md

@@ -97,6 +97,12 @@ maintain sidecar containers without affecting the primary application.
 Sidecar containers share the same network and storage namespaces with the primary
 container. This co-location allows them to interact closely and share resources.
 
+From Kubernetes perspective, sidecars graceful termination is less important. 
+When other containers took all alloted graceful termination time, sidecar containers
+will receive the `SIGTERM` following with `SIGKILL` faster than may be expected. 
+So exit codes different from `0` (`0` indicates successful exit), for sidecar containers are normal
+on Pod termination and should be generally ignored by the external tooling.
+
 ## Differences from init containers
 
 Sidecar containers work alongside the main container, extending its functionality and

content/en/docs/tutorials/configuration/pod-sidecar-containers.md

@@ -69,6 +69,8 @@ Using Kubernetes' native support for sidecar containers provides several benefit
    special care is needed to handle this situation.
 4. Also, with Jobs, built-in sidecar containers would keep being restarted once they are done, even if regular containers would not with Pod's `restartPolicy: Never`.
 
+See [differences from init containers](/docs/concepts/workloads/pods/sidecar-containers/#differences-from-application-containers) to learn more about it.
+
 ## Adopting built-in sidecar containers
 
 The `SidecarContainers` [feature gate](/docs/reference/command-line-tools-reference/feature-gates/) is in beta state starting from Kubernetes version 1.29 and is enabled by default.