kubetools

A collection of simple shell scripts (and notes) to help with Kubernetes and make your life easier

Tools

Note: most of the tools depend on jq

• pod-to-rc.sh - Convert an existing (unmanaged) pod to a replication-controller
• pod-to-rs.sh - Convert an existing (unmanaged) pod to a replicaset
• pod-to-deployment.sh - Convert an existing (unmanaged) pod to a deployment

Basically this is the same shell script that determines by its own name what the conversion destination should be. Example usage:

./pod-to-rc.sh my-pod | kubectl apply -f -

FORCE=true ./pod-to-rc.sh managed-pod

cat my-pod | ./pod-to-rc.sh - > rc.json

• rc-to-rs.sh - Convert a replication-controller to a replicaset resource

Example usage:

cat rc.json | ./rc-to-rs.sh - > rs.json

./rc-to-rs.sh k8s-resource > rc.json

./rc-to-rs.sh k8s-resource 1

(this last example automatically reparents pod from RC to RS)

• rs-to-rc.sh - Convert a replicaset to a replication-controller resource.

Is the exact opposite of the previous tool. You usually don't need to go into this direction but can undo the last previous command with:

./rs-to-rc.sh k8s-resource 1

• find-unamanged-pods.sh - list all pods that don't have a source (owner reference)

• fake-k8s-service.sh - Create a fake k8s service - so it is possible to access external resources from k8s as if they were native

./fake-k8s-service.sh something 1337 192.168.0.1 1337

Interesting third-party tools

• kubectx - Allows you to switch context or namespace easily
• kube-ps1 - Change your shell prompt to now which k8s cluster you are connected to

Notes

How to list all local annotations:

kubectl get rc resource -o go-template='{{range $k,$v := .metadata.annotations}}{{$k}}={{$v}}|{{end}}' | tr '|' '\n' | grep -E "^myorganization.com$"

How to clean-up failed pods:

for i in $(kubectl get pods -o jsonpath='{range .items[*]}{.metadata.name},{.metadata.namespace} {end}'  --field-selector=status.phase=Failed --all-namespaces); do kubectl delete pod $(cut -d"," -f 1 <<< $i) --namespace  $(cut -d"," -f 2 <<< $i); done