Update linkerd loglevel for a deployment

linkerd-set-log-level.sh

#!/bin/bash

# Usage: ./linkerd-set-log-level.sh app-name level

APP=$1
LEVEL=$2

declare -a PODS=($(
  kubectl               \
    get                 \
    pods                \
    --selector=app=$APP \
    -o json |           \
    jq -r '.items[].metadata.name'
))

for pod in "${PODS[@]}"
do
  echo "Updating linkerd-proxy log level to *$LEVEL* for $pod..."

  # Background port-fowarding
  kubectl port-forward $pod linkerd-admin &> /dev/null &

  # Give a second for the port-forward to be setup
  sleep 1

  # Submit the request to change the level
  curl --data "linkerd=$LEVEL" -X PUT localhost:4191/proxy-log-level

  # Kill the port-forward and wait for it to exit; supressing the termination
  kill $!
  wait $!  2>/dev/null
done