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. (Note that there is currently no "blacklist" option)
Complete example:
custom:
dotenv:
path: path/to/my/.env (default ./.env)
basePath: path/to/ (default ./)
include:
- AUTH0_CLIENT_ID
- AUTH0_CLIENT_SECRET
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.