kubectl port-forward service made easy

README.md

A script to port-forward via Service name

• kubectl should support port-forwarding with service name but it doesn't
• k9s does though 👍🏼
• So this script mimics its behavior

credits:

• https://stackoverflow.com/a/60221588/1570165

Roadmap (maybe)

• maintain as a repo instead of gist
• publish as a kubectl plugin

pfs.sh

#!/usr/bin/env bash

set -e

command -v kubectl > /dev/null || (echo "kubectl not detected and exiting." && exit 1)

function print_usage {
  echo "usage:"
  echo "pfs.sh SERVICE_NAME PORTS"
  echo ""
  echo "examples:"
  echo '- `pfs.sh prometheus 9090`'
  echo '- `KUBE_NAMESPACE=my-namespace pfs.sh prometheus 9090:10090`'
  echo '- `export KUBE_NAMESPACE=my-namespace; pfs.sh prometheus 9090 9093`'
  echo ""
  echo 'run `kubectl port-forward -h` to get more help'
}

svc="$1"

if test -z "${svc}"; then
  print_usage
  exit 1
fi

shift
ports="$@"

if test -z "${ports}"; then
  print_usage
  exit 1
fi

if test -n "${KUBE_NAMESPACE}"; then
  namespace=" -n ${KUBE_NAMESPACE} "
else
  namespace=""
fi

ip_addrs="$(kubectl ${namespace} get ep $svc -o=jsonpath='{.subsets[*].addresses[*].ip}' | tr ' ' '\n')"
random="$(echo "${ip_addrs}" | shuf | head -n1)"

podname="$(echo "${random}" | xargs -I % kubectl ${namespace} get pods -o=name --field-selector=status.podIP=%)"

echo "${podname} is selected for ${svc}"

kubectl ${namespace} port-forward $podname $ports