home/.local/script/kubectl-ssh

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2024-03-26 21:15:01 +00:00
#!/usr/bin/env bash
set -e
ssh_node() {
node=$1
if [ "$node" = "" ]; then
node=$(kubectl get node -o name | sed 's/node\///' | tr '\n' ' ')
node=${node::-1}
if [[ "$node" =~ " " ]]; then
echo "Node name must be specified. Choose one of: [$node]"
exit 1
else
echo "Single-node cluster detected. Defaulting to node $node"
fi
fi
pod=$(
kubectl create -o name -f - <<EOF
apiVersion: v1
kind: Pod
metadata:
generateName: ssh-node-
labels:
plugin: ssh-node
spec:
nodeName: $node
containers:
- name: ssh-node
image: busybox
imagePullPolicy: IfNotPresent
command: ["chroot", "/host"]
tty: true
stdin: true
stdinOnce: true
securityContext:
privileged: true
volumeMounts:
- name: host
mountPath: /host
volumes:
- name: host
hostPath:
path: /
hostNetwork: true
hostIPC: true
hostPID: true
restartPolicy: Never
EOF
)
deletePod() {
kubectl delete $pod --wait=false
}
trap deletePod EXIT
echo "Created $pod"
echo "Waiting for container to start..."
kubectl wait --for=condition=Ready $pod >/dev/null
kubectl attach -it $pod -c ssh-node
}
ssh_pod() {
# TODO: improve this
if [ "$1" == "" ]; then
echo "Pod name must be specified."
exit 1
fi
kubectl exec -it "$@" bash || (
echo "Running bash in pod failed; trying with sh"
kubectl exec -it "$@" sh
)
}
print_usage() {
echo "Provider-agnostic way of opening a remote shell to a Kubernetes node."
echo
echo "Enables you to access a node even when it doesn't run an SSH server or"
echo "when you don't have the required credentials. Also, the way you log in"
echo "is always the same, regardless of what provides the Kubernetes cluster"
echo "(e.g. Minikube, Kind, Docker Desktop, GKE, AKS, EKS, ...)"
echo
echo "You must have cluster-admin rights to use this plugin."
echo
echo "The primary focus of this plugin is to provide access to nodes, but it"
echo "also provides a quick way of running a shell inside a pod."
echo
echo "Examples: "
echo " # Open a shell to node of a single-node cluster (e.g. Docker Desktop)"
echo " kubectl ssh node"
echo
echo " # Open a shell to node of a multi-node cluster (e.g. GKE)"
echo " kubectl ssh node my-worker-node-1"
echo
echo " # Open a shell to a pod"
echo " kubectl ssh pod my-pod"
echo
echo "Usage:"
echo " kubectl ssh node [nodeName]"
echo " kubectl ssh pod [podName] [-n namespace] [-c container]"
exit 0
}
if [ "$1" == "--help" ]; then
print_usage
fi
if [[ "$1" == node/* ]]; then
ssh_node ${1:5}
elif [ "$1" == "node" ]; then
ssh_node $2
elif [[ "$1" == pod/* ]]; then
ssh_pod "$@"
elif [ "$1" == "pod" ]; then
shift
ssh_pod "$@"
else
print_usage
fi