What is the primary purpose of a Readiness Probe in OpenShift?

• A. It determines if a pod should be included in the service endpoints.
• B. It detects if the container is alive and restarts it if needed.
• C. It sets the resource limits for the container.
• D. It defines the order of startup for containers.

Answer: (A)

Readiness probes determine when a container is ready to receive traffic. When the readiness check passes, the pod is added to the service’s endpoints so it can handle requests. If the check fails, the pod is removed from the endpoints and won’t get traffic until it passes again. This keeps traffic flowing only to containers that are prepared to serve it, which is especially important during startup, after a failure, or during rolling updates.

In contrast, a liveness probe checks if the container is still alive and can trigger a restart if it isn’t. Resource limits are configured in the pod’s resource requests/limits, not through probes. Startup order isn’t guaranteed by readiness probes; they’re about readiness to serve, not the sequence of container starts (though there is a startupProbe that can delay readiness until startup tasks finish).