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Use netshoot to peek inside your k8s app

TIL there’s a thing called netshoot. It is an ultra-lightweight workspace container with all the network essential tools in it. This is the perfect thing when trying to make sense of domain name resolution and networking, which can get really hairy really fast in Kubernetes. Here’s how to just run one pod and have it delete (“Terminate”) after you exit:

#!/bin/bash

exec kubectl run netshoot --rm -it \
  --image nicolaka/netshoot \
  --namespace "${1:-$(ns)}" \
  -- /bin/bash

This accepts a single argument for the namespace since that is often the thing that changes and isolates the scope of a cloud-native application. (You would have to have the ns shortcut command for this to work.)

If you have Istio installed in your cluster, things get more complicated. You might just want to disable it for your netshoot pod:

#!/bin/bash

overrides='
{
  "metadata": {
    "annotations": {
      "sidecar.istio.io/inject": "false"
    }
  }
}
'

exec kubectl run netshoot --rm -it \
  --image nicolaka/netshoot:latest \
  --namespace "${1:-$(ns)}" \
  --overrides "$overrides" \
  -- /bin/bash

Also see:

• Use k config view –minify to Get Current Namespace
• Istio Fucks Up kubectl run, Forever

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