CODEWITHSUNDEEP
node.js
Ben
Ben

Reputation: 5361

How can I use environment variables in JSON files?

I'm using a 3rd party library that needs a JSON config file, and I need to pass some env variables in as key values. If I include them as I normally would, eg:

  "s3": {
    "key": process.env.AWS_ACCESS_KEY_ID,
    "secret": process.env.AWS_SECRET_ACCESS_KEY,
    "bucket": process.env.S3_MLL_BUCKET_NAME,
    "destination": "/backups/database",
    "encrypt": false,
    "region": process.env.AWS_REGION
  }

...I get the error:

SyntaxError: config/s3_backup.config.json: Unexpected token p

Upvotes: 46

Views: 125542

Answers (3)

Steven Muganwa
Steven Muganwa

Reputation: 480

What worked for me was using a js file and exporting an object:

module.exports = {config: {"exampleAPIKey":"ruier4343"}}

Then I stringified the object and then parsed it back to json:

const config = require("./jsConfigs.js").config;
const jsonConfig = JSON.parse(JSON.stringify(config));

Upvotes: 8

Sharath Jallu
Sharath Jallu

Reputation: 143

I faced similar issue where i have to pass Env variables inside config.json and my 3rd party system accepts mainly config.json.

Here is the workaround that worked for me.

  1. My app.js gets executed inside start script of package.json
  2. So During Runtime (i.e deployment which runs command 'npm run start') it will update config.json dynamically using below code placed inside app.js (before creating server).

App.js

    //updating config.json to use environment variables during run time
    const fs = require('fs');
    const fileName = './public/config.json';
    const file = require(fileName);
    if (file && file.arguments && file.arguments.execute)
        file.arguments.execute.url = process.env.executeUrl || "";

    if (file && file.configurationArguments && file.configurationArguments.publish)
        file.configurationArguments.publish.url = process.env.publishUrl || "";

    fs.writeFile(fileName, JSON.stringify(file, null, 2), function writeJSON(err) {
        if (err)
            return console.log(err);
        console.log('updated config.json');
    });
    http.createServer(app).listen(app.get('port'), function() {
        console.log('App Express server listening on port ' + app.get('port'));
    });

Upvotes: 4

dtoux
dtoux

Reputation: 1884

JSON does not have notion of environment variables. What you can do though is to declare your configuration file as node.js module and then you will be able to use your environment variables as follows:

module.exports = {
  s3: {
    key: process.env.AWS_ACCESS_KEY_ID,
    secret: process.env.AWS_SECRET_ACCESS_KEY,
    bucket: process.env.S3_MLL_BUCKET_NAME,
    destination: "/backups/database",
    encrypt: false,
    region: process.env.AWS_REGION
  }
};

Upvotes: 45

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