Kube-probe HTTP probe failed with status code 401

What is Kube-probe HTTP probe failed with status code 401

Understanding Kube-probe

Kube-probe is an essential component of Kubernetes, designed to monitor the health of applications running within a cluster. It helps ensure that containers are running smoothly by performing periodic checks, known as probes, on the containers. These probes can be of different types, such as HTTP, TCP, or command-based, and are crucial for maintaining the reliability and availability of applications.

Identifying the Symptom

When using Kube-probe, you might encounter an error message stating: HTTP probe failed with status code 401. This indicates that the HTTP probe was unable to successfully authenticate with the endpoint it was trying to access.

Details of the Issue

The HTTP status code 401 Unauthorized is returned when the request lacks valid authentication credentials for the target resource. In the context of Kube-probe, this means that the probe is attempting to access an endpoint that requires authentication, but it has not been provided with the necessary credentials.

Why Authentication Matters

Authentication is a critical aspect of securing endpoints, ensuring that only authorized entities can access certain resources. In Kubernetes, probes need to be configured correctly to access these secured endpoints without causing disruptions.

Steps to Resolve the Issue

1. Verify Endpoint Requirements

First, confirm whether the endpoint being probed requires authentication. You can do this by checking the service documentation or consulting with the development team responsible for the service.

2. Configure Authentication for the Probe

If authentication is required, you need to configure the probe with the necessary credentials. This can be done by adding the appropriate headers or tokens to the probe configuration in your Kubernetes deployment YAML file. For example:

livenessProbe: httpGet: path: /healthz port: 8080 httpHeaders: - name: Authorization value: "Bearer <your-token>"

Replace <your-token> with the actual token or credentials required for authentication.

3. Disable Authentication for the Probe Endpoint (If Applicable)

If the endpoint is meant to be publicly accessible or if authentication is not strictly necessary for health checks, consider disabling authentication for the probe endpoint. This can often be configured in the service's settings or by adjusting the access control policies.

Additional Resources

For more information on configuring probes in Kubernetes, refer to the official Kubernetes documentation on probes. Additionally, for a deeper understanding of HTTP status codes, you can visit MDN Web Docs on HTTP 401.