Kubernetes Network Detective

This tool is used to validate the network setup of a Kubernetes cluster. It goes beyond the basic e2e tests and verifies each node of a cluster. This allows to find even the most arcane or temporary network problems.

Test Bed

Before any testing the following test bed is being created:

• Ephemeral Namespace
• Two pods per node. One with hostNetwork mode enabled, one without.
• For each pod a service is created. A unique external IP is assigned to each.

Test Scenarios

To test connectivty the tool will call a kubectl exec wget http://$IP:$PORT. It tests the following scenarios.

• Connectivity from Pod to Pod
• Connectivity from Pod to ClusterIP to Pod
• Connectivity from Pod to ExternalIP to Pod

It tests all possible permutations. This is not feasable for large clusters... Only schedulable nodes are taken into account.

Running

Default load order for .kubeconfig applies. If you have a working kubectl it will just work

kube-detective -externalCIDR 10.44.11.32/27

Additional logging can be enabled by setting --v=2 or --v=3.

Docker image

Docker image with latest binary is available at sapcc/kube-detective.