Kenv

Treat environment variables like json objects. process.kenv.nowThis?.isPossible!

• Easily manage and consolidate app secrets through a flexible environment configuration.
• Support nested configuration objects. (For example, Google Cloud Platform uses service-account json files for server-server authentication.)
• Support primitive types. process.kenv.BOOLEAN_VALUE === true.
• Validate syncing between your local, sample and production config files.
• Get a real-time view of how environment variables are used in your system.
• Introduce typescript intellisense to effectively locate and use environment variables.

Kenv loads a json or jsonc (json with comments) file into a unique process.kenv property. Kenv supports node, typescript and webpack client/server.

Usage

# install
yarn add kenv
# [or]
npm i --save kenv

# prepare the two config files that kenv requires
echo '{"TEST_KEY":{"INNER_KEY":true}}' > ./.kenv.json # development-only config
echo '{"TEST_KEY":{"INNER_KEY":true}}' > ./.kenv.sample.json # sample config committed to source

Then load kenv at the top of your node/typescript entrypoint.

// sample.js
require("kenv").config({
  // all configurations are optional
  environmentPath: '.kenv.json', // the main jsonc file to load
  environmentTemplatePath = '.kenv.sample.json', // template file to validate syncing
  whitelistKeys = [], // keys to ignore for validation
  throwOnMissingKeys: false, // exit with an error instead of a console.warn when keys are out of sync  (default: false)
  devSyncPaths = ['.kenv.production.json', '.kenv.staging.json'] // extra config files to validate syncing during development
  freeze: false, // makes process.kenv readonly (default: false)
  logUsage: false, // logs usage of environment keys on the console (default: false). Alternatively, use KENV_LOG_USAGE in .kenv.json.
})

// or
import { config } from kenv
config()

// then anywhere else in your code
console.log(process.kenv.TEST_KEY.INNER_KEY) // logs true

• config() also returns the loaded json object.
• inline comments are supported in json files.
• nested object access is case-sensitive.
• use devSyncPaths while developing to ensure that the different config files are in sync.

The logUsage option

logUsage enables environment key usage logging. This is useful to find out which scripts are calling process.kenv variables. A sample output follows:

[kenv] SPECIAL_ENV_KEY                                      xxx3343-f3*********
       /path/to/the/script/index.js:22:15

We recommend only enabling this in dev environments as it requires stack tracing to gather information.

Usage with webpack

To use process.kenv in webpack scripts, use the getDefinePluginConfig to configure webpack.definePlugin:

const { getDefinePluginConfig, config } = require("kenv")
const { DefinePlugin } = require("webpack")

config()

// then in your webpack configurations:
webpackConfig.plugins.push(
  new DefinePlugin({
    "process.kenv": getDefinePluginConfig({
      // all configurations are optional
      kenvironment: process.kenv, // specify an object. defaults to `process.kenv`
      hideKeys: ["list", "of.hidden.keys"], // list of keys that won't be published to webpack (case-sensitive)
    }),
  })
)

// then anywhere else in your webpack-based js/ts code
console.log(process.kenv.some.environment.variable)

• Use getDefinePluginConfig to define and control which environment variables to publish to webpack. This is useful if you wish to hide certain keys in compile-time, client-side and server-side environments.

Logging environment variables safely to the console

Kenv provides a getRedactedDump helper to safely expose an environment dump to the console. This is useful for deployment debugging.

const { config, getRedactedDump } = require("kenv")

config()

const redactedKenvDump = getRedactedDump({
  // all configurations are optional
  kenvironment: process.kenv, // specify an object, defaults to `process.kenv`
  decimalPercentageToShow: 0.3, // the amount to mask relative to the size of the string
  truncateLength: 20, // truncates values to the specified character length
  hideKeys: ["keys.to.hide"], // explicitly prevents showing these keys
})

// Dumps to the console, with double-space formatting.
console.log(JSON.stringify(redactedKenvDump, null, 2))

// Example output:
{
  "A.NESTED.SECRET": "abc********",
  "BOOLEAN_RULE": true,
  "NUMBER_KEY": 25.00,
  "A_LONG_NUMBER": 231231204293
}

Adding typescript intellisense for your kenv variables

Add a similar typescript declaration file to your root:

// kenv.d.ts
import kenvVariables from "./.kenv.sample.json"

declare global {
  namespace NodeJS {
    interface Process {
      kenv: typeof kenvVariables
    }
  }
}

// If this file has no import/export statements (i.e. is a script)
// convert it into a module by adding an empty export statement.
export {}

FAQs

Why does kenv require creating a new process property?

process.env is reserved for string-only variables. By creating a new global process property, we can specify our own environment structure.

Should I completely replace process.env with process.kenv?

Cloud hosting services have different ways to set .env variables. It is left to the user to use .kenv solely or in combination with .env.

How can I use kenv with cli-based applications?

We recommend creating a patched bin/cli file in your home directory, e.g.

touch my-cli-override.js;
chmod +x ./my-cli-override.js

// my-cli-override.js
require("kenv").config()
require("cli/to/override.js")

// package.json
{
  "scripts": {
    "start": "./my-cli-override.js start"
  }
}

What does kenv use for its dependencies?

Kenv uses json5 to parse Jsonc and Json files, flat to preprocess webpack.DefinePlugin configs, deep-freeze to make process.kenv contents readonly, and colors to add color to the console outputs.

Can you recommend a single-config environment workflow?

• Create environment specific .kenv configurations.
  • .kenv.sample.json for developer reference
  • .kenv.json for local development
  • .kenv.production.json for deployed apps
  • make sure you gitignore everything apart from the sample file.
• Publish your environment-specific configs to AWS or Google Cloud Secrets Manager. Other options include AWS parameter store and AWS/Google KMS.
• Use AWS CodeDeploy or GCP Cloudbuild to decrypt and dump the secrets into a .kenv.json file prior to building or starting your app.

Inspiration

• dotenv
• yenv
• process.env

Other projects

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