Kube-probe is a diagnostic tool used in Kubernetes to monitor the health of applications running in a cluster. It helps ensure that applications are functioning correctly by checking their readiness and liveness. Kube-probe can perform HTTP, TCP, and command-based checks to determine the state of an application.
One common issue encountered with Kube-probe is the error message: TCP probe failed: connection refused. This indicates that the probe was unable to establish a TCP connection to the application on the specified port.
The 'connection refused' error typically means that there is no process listening on the specified port, or the application is not running. This can occur if the application has crashed, is not configured correctly, or the port is incorrect.
First, check if the application is running. You can use the following command to list all running pods and their statuses:
kubectl get pods
If the application pod is not running, investigate the logs to determine why it failed to start:
kubectl logs <pod-name>
Ensure that the application is configured to listen on the correct port. You can check the container's configuration in the deployment YAML file:
kubectl describe pod <pod-name>
Look for the ports
section to verify the correct port is exposed.
Check if any network policies or firewall rules are blocking the connection. You can review network policies using:
kubectl get networkpolicy
Ensure that the policies allow traffic to the specified port.
If the application was not running, try restarting it:
kubectl rollout restart deployment <deployment-name>
For more information on configuring probes in Kubernetes, refer to the official Kubernetes documentation. Additionally, you can explore troubleshooting steps for debugging applications in Kubernetes.
(Perfect for DevOps & SREs)
(Perfect for DevOps & SREs)