serverless-dotenv-plugin

What is serverless-dotenv-plugin?

The serverless-dotenv-plugin is a Serverless Framework plugin that automatically loads environment variables from a .env file into your serverless project. This allows you to manage environment-specific configurations and secrets in a centralized and secure manner.

What are serverless-dotenv-plugin's main functionalities?

Load Environment Variables

This feature allows you to load environment variables from a .env file into your serverless project. The code sample demonstrates how to configure the serverless-dotenv-plugin in the serverless.yml file and access an environment variable in a function.

module.exports = {
  service: 'my-service',
  plugins: ['serverless-dotenv-plugin'],
  provider: {
    name: 'aws',
    runtime: 'nodejs14.x'
  },
  functions: {
    hello: {
      handler: 'handler.hello',
      environment: {
        MY_ENV_VAR: process.env.MY_ENV_VAR
      }
    }
  }
};

Custom .env File Path

This feature allows you to specify a custom path for your .env file. The code sample shows how to configure the plugin to load environment variables from a .env file located in a custom directory.

module.exports = {
  service: 'my-service',
  plugins: ['serverless-dotenv-plugin'],
  custom: {
    dotenv: {
      path: './config/.env'
    }
  },
  provider: {
    name: 'aws',
    runtime: 'nodejs14.x'
  },
  functions: {
    hello: {
      handler: 'handler.hello',
      environment: {
        MY_ENV_VAR: process.env.MY_ENV_VAR
      }
    }
  }
};

Multiple Environment Files

This feature allows you to use different .env files for different environments. The code sample demonstrates how to configure the plugin to load environment variables from different .env files based on the environment.

module.exports = {
  service: 'my-service',
  plugins: ['serverless-dotenv-plugin'],
  custom: {
    dotenv: {
      path: {
        development: './config/.env.development',
        production: './config/.env.production'
      }
    }
  },
  provider: {
    name: 'aws',
    runtime: 'nodejs14.x'
  },
  functions: {
    hello: {
      handler: 'handler.hello',
      environment: {
        MY_ENV_VAR: process.env.MY_ENV_VAR
      }
    }
  }
};

Other packages similar to serverless-dotenv-plugin

dotenv

dotenv is a popular package for loading environment variables from a .env file into process.env. It is widely used in Node.js applications but does not have built-in support for the Serverless Framework. You would need to manually integrate it into your serverless project.

serverless-secrets-plugin

serverless-secrets-plugin is another Serverless Framework plugin that helps manage secrets and environment variables. It integrates with AWS Secrets Manager to securely store and retrieve secrets. Unlike serverless-dotenv-plugin, it focuses on using AWS Secrets Manager rather than .env files.

serverless-env-generator

serverless-env-generator is a plugin that generates environment variables for your serverless project based on a configuration file. It provides more flexibility in generating environment variables but requires additional configuration compared to serverless-dotenv-plugin.

README

serverless-dotenv-plugin

Preload Environment Variables Into Serverless

Use this plugin if you have variables stored in a .env file that you want loaded into your serverless yaml config. This will allow you to reference them as ${env:VAR_NAME} inside your config and it will load them into your lambdas.

Install and Setup

First, install the plugin:

> npm i -D serverless-dotenv-plugin

Next, add the plugin to your serverless config file:

service: myService
plugins:
  - serverless-dotenv-plugin
...

Now, just like you would using dotenv in any other JS application, create your .env file in the root of your app:

DYANMODB_TABLE=myTable
AWS_REGION=us-west-1
AUTH0_CLIENT_ID=abc12345
AUTH0_CLIENT_SECRET=12345xyz

Automatic Env file name resolution

By default, the plugin looks for the file: .env. In most use cases this is all that is needed. However, there are times where you want different env files based on environment. For instance:

.env.development
.env.production

When you deploy with NODE_ENV set: NODE_ENV=production sls deploy the plugin will look for a file named .env.production. If it doesn't exist it will default to .env. If for some reason you can't set NODE_ENV, you could always just pass it in as an option: sls deploy --env production. If NODE_ENV or --env is not set, it will default to development.

Valid .env file names	Description
.env	Default file name when no other files are specified or found.
.env.development	If NODE_ENV or --env is not set, will try to load .env.development. If not found, load .env
.env.{ENV}	If NODE_ENV or --env is set, will try to load .env.{env}. If not found, load .env

Plugin options

path: path/to/my/.env

The plugin will look for your .env file in the same folder where you run the command using the file resolution rules as described above, but these rules can be overridden by setting the path option.

basePath: path/to/my/

The problem with setting the path option is that you lose environment resolution on the file names. If you don't need environment resolution, the path option is just fine. If you do, then use the basePath option.

include: ...

All env vars found in your file will be injected into your lambda functions. If you do not want all of them to be injected into your lambda functions, you can whitelist them with the include option.

logging: true|false (default true)

(Added Feb 2, 2020 by @kristopherchun)

By default, there's quite a bit that this plugin logs to the console. You can now quiet this with the new logging option. (This defaults to true since this was the original behavior)

Complete example:

custom:
  dotenv:
    path: path/to/my/.env (default ./.env)
    basePath: path/to/ (default ./)
    logging: false
    include:
      - AUTH0_CLIENT_ID
      - AUTH0_CLIENT_SECRET

exclude: ...

If you do not want all of them to be injected into your lambda functions, you can blacklist the unnecessary ones with the exclude option.

Example:

custom:
  dotenv:
    exclude:
      - NODE_ENV # E.g for Google Cloud Functions, you cannot pass this env variable.

Usage

Once loaded, you can now access the vars using the standard method for accessing ENV vars in serverless:

...
provider:
  name: aws
  runtime: nodejs6.10
  stage: ${env:STAGE}
  region: ${env:AWS_REGION}
...

Lambda Environment Variables

Again, remember that when you deploy your service, the plugin will inject these environment vars into any lambda functions you have and will therefore allow you to reference them as process.env.AUTH0_CLIENT_ID (Nodejs example).

Examples

You can find example usage in the examples folder.