Kubectl useful commands

export-secrets-configmaps.sh

#!/bin/bash
set -e

# Export all secrets and configmaps in all namespaces to files
# Every file will have name <namespace>__<type>__<name>.yaml
# e.g. default__secret__database.yaml

namespaces=$(kubectl get namespace | awk '{print $1}' | tail -n +2)
for ns in $namespaces
do
    if [[ "$ns" == *"kube-system"* ]]; then
        echo "Skipping namespace $ns"
        continue
    fi

    echo "Checking namespace $ns for secrets and configmaps"

    # Add other objects (statefulset,svc,deployment etc) here to also be exported
    for n in $(kubectl get -o=name -n=$ns configmap,secret)
    do
        if [[ "$n" == *"kube-root-ca"* ]] || [[ "$n" == *"default-token"* ]]; then
            echo "Skipping $n"
            continue
        fi
        echo "Exporting $n"
        filename=$(sed s:/:__:g <<< $n)
        kubectl get -o=yaml -n=$ns $n > "${ns}__${filename}.yaml"
        # Delete creationTimestamp, resourceVersion and uid lines
        sed -i '/creationTimestamp:/d;/resourceVersion:/d;/uid:/d' "${ns}__${filename}.yaml"
    done
done

kubectl.sh

# Show all secrets being used by pods in all namespaces
# Does not filter out null values
kubectl get pods --all-namespaces -o json | jq '.items[] | [{pod:.metadata.name , secrets: [.spec.containers[].env[]?.valueFrom.secretKeyRef.name] }]' > pod-secrets.json

# Show pods in all namespaces that run on given node
kubectl get pods --all-namespaces -o wide --field-selector spec.nodeName=

# Show every node's CPU and memory requests and limits
kubectl describe nodes | grep 'Name:\|  cpu\|  memory'