Wraps "helm package" in order to be able to --set values at package time. Depends on yq and helm.

helm-package.sh

#!/usr/bin/env bash

scriptName=$(basename "$0")

USAGE="Wraps \"helm package\" in order to be able to --set values at package time.

Usage:
  $scriptName \\
    --set key1=value1 --set key2=value2 \\
    [--app-version 1.2.3] <chart-path>"
    
set -e

function error() {
  echo -e "$1" >&2
  exit 1
}

if [[ "$#" -eq 0 ]]; then
    error "$USAGE";
fi

type helm &>/dev/null || error "helm not installed"
type yq &>/dev/null || error "yq not installed"

setValues=()
originalArgs=()

while [[ $# -gt 0 ]]; do
  key="$1"

  case $key in
  --set)
    # specifically --set key=value format - this are for processing by this script only and shouldn't be passed
    # to Helm package.
    setValues+=("$2")
    shift # past argument
    shift # past key/value pair
    ;;
  --*=*)
    # --option=value format
    originalArgs+=("$1")
    shift
    ;;
  --*)
    originalArgs+=("$1")
    if [[ ! "$2" =~ ^--* ]]; then
      # if next argument doesn't start with a "--" assume is the value for this argument
      originalArgs+=("$2")
      shift
    fi
    shift
    ;;
  *) # nameless option - no "--" - must be the chart directory
    chartPath=$1
    originalArgs+=("$1")
    shift
    ;;
  esac
done
set -- "${originalArgs[@]}" # restore positional parameters

[ -d "${chartPath}" ] || error "Directory ${chartPath} does not exist"
valuesFile="${chartPath%/}/values.yaml"
[ -f "${valuesFile}" ] || error "File ${valuesFile} does not exist"

valuesBackupFile="${chartPath%/}/values.yaml.bak"
cp "${valuesFile}" "${valuesBackupFile}"

function cleanup {
  # restore values file
  cp "${valuesBackupFile}" "${valuesFile}"
  rm -f "${valuesBackupFile}"
}
trap cleanup EXIT

# set values using yq
for keyValue in "${setValues[@]}"; do
  key="${keyValue%=*}"
  value="${keyValue#*=}"
  echo "Setting \"${key}\" to value \"${value}\""
  yq w -i "${valuesFile}" "${key}" "${value}"
done

helm package "${originalArgs[@]}"