Build a JSON string with Bash variables

Question

I need to read these bash variables into my JSON string and I am not familiar with bash. any help is appreciated.

#!/bin/sh

BUCKET_NAME=testbucket
OBJECT_NAME=testworkflow-2.0.1.jar
TARGET_LOCATION=/opt/test/testworkflow-2.0.1.jar

JSON_STRING='{"bucketname":"$BUCKET_NAME"","objectname":"$OBJECT_NAME","targetlocation":"$TARGET_LOCATION"}'


echo $JSON_STRING 

Answer 1

For Node.js Developer, or if you have node environment installed, you can try this:

JSON_STRING=$(node -e "console.log(JSON.stringify({bucketname: $BUCKET_NAME, objectname: $OBJECT_NAME, targetlocation: $TARGET_LOCATION}))")

Advantage of this method is you can easily convert very complicated JSON Object (like object contains array, or if you need int value instead of string) to JSON String without worrying about invalid json error.

Disadvantage is it's relying on Node.js environment.