Deno Config

Utility to streamline your deno app config management through cli, .env and json files.

Installation

deno-config is hosted at https://deno.land/x/deno_config and can be imported like this. Check latest version in deno.land when you want to import.

import { augmentConfiguration } from 'https://deno.land/x/deno_config@v0.1.2/mod.ts';

Usage

deno-config accepts a config object as the source of truth and applies changes to it according to cli, env files or json files.

// config.ts

import { augmentConfiguration } from '...';

export const Config = {
  port: 8080,
  db: {
    host: 'localhost',
    port: 27017,
    name: 'my-db'
  },
  cors: {
    allowed: false,
    allowedHosts: []
  }
};

augmentConfiguration(config);

deno-config changes (augments) this object according to options passed through cli as described below.

Note: deno-config always follows this config objects structure. if a property does not exist in this object, deno-config will not add it.

Cli

You can augment your config object using cli by giving arguments like this: --config-{keyPath}={value}. You can nest key path by using - like this --config-db-port=3000. One example of using cli is this.

// if you run your app like this
// deno run app.ts --config-port=3000 --config-db-host=127.0.0.1 --config-cors-allowed --config-cors-allowedHosts=khoshghadam.com --config-cors-allowedHosts=yooneskh.ir
// your config file will be this

{
  port: 3000,
  db: {
    host: '127.0.0.1',
    port: 27017,
    name: 'my-db'
  },
  cors: {
    allowed: true,
    allowedHosts: ['khoshghadam.com', 'yooneskh.ir']
  }
}

Note usage of arrays and booleans. If a property is array in your config object, specifing value for it through cli will add the value to the array. boolean values can be given with true and false but omitting =true will imply true as in --config-cors-allowed.

JSON files

You can specify JSON file path like this --json-config={json file path} and deno-config will merge it with the config object.

// ./config/sample-config.json
{
  "port": 3000,
  "cors": {
    "allowed": true,
    "allowedHosts": ['khoshghadam.com', 'yooneskh.ir']
  }
}

// if you run your app like this
// deno run app.ts --json-config=./config/sample-config.json
// your config file will be this
{
  port: 3000,
  db: {
    host: 'localhost',
    port: 27017,
    name: 'my-db'
  },
  cors: {
    allowed: true,
    allowedHosts: ['khoshghadam.com', 'yooneskh.ir']
  }
}

Env files

You can specify env file path like --env-config={env file path} and deno-config will augment you config object with it. each line must have this format {keyPath}={value}. you can nest keyPath with . as in db.host=localhost

// ./.env
port=3000

cors.allowed=true
cors.allowedHosts=khoshghadam.com
cors.allowedHosts=yooneskh.ir

// if you run your app like this
// deno run app.ts --env-config=./.env
// your config file will be this
{
  port: 3000,
  db: {
    host: 'localhost',
    port: 27017,
    name: 'my-db'
  },
  cors: {
    allowed: true,
    allowedHosts: ['khoshghadam.com', 'yooneskh.ir']
  }
}

Note usage of arrays and booleans. You cannot omit =true in env files and they must be explicitly specified.

further examples are in ./examples directory.

Licence

Use as you wish.