This script get's the netns from a Kubernetes pod

get_pod_netns.sh

#### WAY with crictl 
#### TODO validate crictl with docker runtime !!

# Get all pods of a specific node 
#kubectl  get po --field-selector=spec.nodeName="fluffy-master" --all-namespaces
kubectl get --all-namespaces po --field-selector=spec.nodeName=="$(hostname)" -o json | jq -r '.items[] | select(.status.hostIP!=.status.podIP) | "\(.metadata.name) \(.metadata.namespace)"'

# Get the Pod ID of the Pod with crictl
POD_ID=$(sudo crictl pods --name=nginx-6f858d4d45-vnszm --namespace=default -q --no-trunc)

# Get the network namespace of this pod
NETNS=$(sudo crictl inspectp ${POD_ID} | jq -r '.info.runtimeSpec.linux.namespaces[] |select(.type=="network") | .path')

# Jump into the network namespace and execute something
sudo nsenter --net=${NETNS} ip -o a s

in case you're running somewhere with no jq
crictl inspectp ${POD_ID} | grep "/var/run/netns" | grep path | awk '{print $2}'