bash script to shorten helm release names

helm-release-shortener

#!/usr/bin/env bash

set -euo pipefail

RELEASE_NAME=$1
MAX_LENGTH=${2-53}
HASH_SIZE=${3-8}

if [[ $MAX_LENGTH -le $(($HASH_SIZE+1)) ]]; then
    echo "max length must be bigger than hash size + 1"
    exit 1
fi


if [[ ${#RELEASE_NAME} -le $MAX_LENGTH ]]; then
    echo -n $RELEASE_NAME
    exit
fi

TRUNCATION_SIZE=$(($MAX_LENGTH-$HASH_SIZE-1))
TRUNCATION=${RELEASE_NAME:0:$TRUNCATION_SIZE}

RELEASE_NAME_HASH=$(echo -n $RELEASE_NAME | sha1sum | awk '{print $1}')

echo -n $TRUNCATION-${RELEASE_NAME_HASH:0:$HASH_SIZE}