shared-node-env

SharedNodeEnv

A Node.js library designed to handle the creation of shared Environment Variables within multiple node applications running on the same server and sharing identical environmental variables that must be updated across all applications when changed.

The library also allows for a application specific local environments variable file to be created that holds environment variables that are specific to that application. If the local environments variable file contains any entries that are identical to those in the shared file, the local variables will take precedence, effectively overriding the shared variable with the local value.

Installation

npm install shared-node-env --save

Configuration

The library can accept an optional configuration object that defines two optional configuration values.

Format

{
    sharedEnv: 'path-to-shared-env-file/.env-shared', // default = undefined
    localEnv: 'path-to-local-env-file/.env-local',    // default = '.env-local'
    local: true                                       // default = true
}

sharedEnv

Specifies the absolute path to the shared environment variables file. The file must be named .env-shared and can be located anywhere on the server's file system so long as all Node.js applications that utilize the shared environment variables can access it.

localEnv

Specifies the absolute path to the local environment variables file. This file is meant to be application specific and should only be loaded by a single application. This value ONLY needs to be passed in if the local file is not located in the default location at the root of the Node.js application. No matter where the file is located it must be named .env-local.

local

Because the library assumes the existence of a local environments file the ability to turn off local is premitted through this configuration value. This is extremely useful when a shared environments file exists but a local does not for a specific application. When set to false the library will not process a local environments file even if one exists.

Notes:

Being that the two environment files will be opened and read by this library, it is important that the user account under which the Node.js application is running has sufficient permissions to open and read them.

Environment File Format (.env-shared, .env-local)

The individual environment files are simply comprised of a single array of key/value objects representing each environment variable you wish to have added to the process.env object or your application. This of course allows you to add as many variables as needed to the file.

[
    {
        "key": "SERVER_ID",
        "value": "123456"
    },
    {
        "key": "SYSTEM_TOKEN",
        "value": "qwe789asd"
    }
]

The library simply iterates over the array and processes each key/value pair adding it to the applications environment variable.

process.env[item.key] = item.value;

Logic

The library first checks to see if a config object has been provided, if not the library assumes it is being used to manage a local environments file and will attempt to load .env-local from the root of the Node.js application.

If a confuguration file is provided the library will check for each of the optional config keys and process each one in order starting with the shared env file and then the local. It is for this reason the local will overwrite values provided by the shared env file.

If local is disabled only the shared environment file will be processed.

Potential Errors

If neither a local file nor a shared file is found the library will throw an error. This is due to the fact that the library is being executed within your Node.js application and expects to perform the task it was created for.

If either the shared or the local environments file being passed is not named correctly an error will be thrown.

If either the shared or the local environments file is empty an error will be thrown.

If either the shared or the local environments file is poorly formatted an error will be thrown.