How to add variables in json file? - json

Question

Below is json file. I want to use variables for db password and db username. How can I add a variable in json ?
{
"name" : "mydb3",
"storage" : {
"binaryStorage" : {
"type" : "database",
"driverClass" : "com.mysql.jdbc.Driver",
"url" : "$jdbcdburl",
"username" : "$jdbcusername",
"password" : "$jdbcpassword"
}
},
"workspaces" : {
"default" : "default",
"allowCreation" : true
}
}

Answer 1

You can either build the JSON up using something like JSON Variables
https://www.npmjs.com/package/json-variables
Or you can load the JSON into memory look for the key and update it, example below using Node.JS
How to update a value in a json file and save it through node.js
Either way you wouldn't have to store the username and passwords in clear text, which is what I am guessing your are trying to avoid?

Answer 2

You may want to try Jsonnet, a data templating language, that is an extension of JSON and can export JSON files. E.g.
{
person1: {
username: "Alice",
password: "abc",
welcome: "Hello " + self.username + "!",
},
person2: self.person1 { username: "Bob", password: "123" },
}
would produce
{
"person1": {
"password": "abc",
"username": "Alice",
"welcome": "Hello Alice!"
},
"person2": {
"password": "123",
"username": "Bob",
"welcome": "Hello Bob!"
}
}
Other than fields you can also declare variables using local, e.g.
local pi = 3.14;

Answer 3

You can use string interpolation + backslash...
See "{{testUrl}}" in Postman exported JSON for exmaple:
Variable value:
"info":{
"_postman_id": "YOUR-ID-IN-POSTMAN",
"name": "YOU-EXPORTED-COLLECTION-FILE-NAME",
"schema": "https://schema.getpostman.com/json/collection/v2.1.0/collection.json",
"testUrl": "https://www.techeader.com"},
Variable implemented in raw:
"url":{
"raw": "\"{{testUrl}}\"",
"protocol": "http",
"host": ["test","com"]},

Answer 4

JSON is a standard format for representing objects as a textual, human readable (most of the time :-/ ) format. The concept of a variable is not applicable in this context. Variables exist in memory/code only, and a variable can be written to JSON format in a file for example, but with the risk of sounding "blunt" IMHO, your question doesn't make much sense at this point.
If you elaborate a little more on what you want to achieve in your application, I might be able to help you better.