Set environment variables from external file in serverless.yml - environment-variables

Question

I'm using serverless and serverless-local for local development.
I've got an external file which holds references to environment variables which I retrieve from node.env in my app.
From what I understand, I should be able to set my environment variables such as
dev:
AWS_KEY: 'key',
SECRET: 'secret
test:
AWS_KEY: 'test-key',
SECRET: 'test-secret',
etc:
...
and have those environment variables included in my app through the following line in my serverless.yml
provider:
name: aws
runtime: nodejs4.3
stage: ${opt:stage, self:custom.default_stage}
deploymentBucket: serverless-deploy-packages/${opt:stage, self:custom.default_stage}
environment:
${file(./serverless-env.yml):${opt:stage, self:custom.default_stage}}
then in the commandline, I call
serverless offline --stage dev --port 9000
I thought this would include the correct vars in my app, but it isn't working. Is this not how it is supposed to work? Am I doing something wrong here?

Answer 1

From docs:
You can set the contents of an external file into a variable:
file: ${file(./serverless-env.yml)}
And later you can use this new variable to access the file variables.
secret: file.dev.SECRET
Or you can use the file directly:
secret: ${file(./serverless-env.yml):dev.SECRET}

Answer 2

You can also now use remote async values with the serverless framework. See https://serverless.com/blog/serverless-v1.13.0/
This means you can call values from s3 or remote databases etc.
Example:
serverless.yml
service: serverless-async-vars
provider:
name: aws
runtime: nodejs6.10
custom:
secret: ${file(./vars.js):fetchSecret} # JS file running async / promised
vars.js
module.exports.fetchSecret = () => {
// async code
return Promise.resolve('SomeSecretKey');
}

Answer 3

This is how you can separate your environments by different stages:
serverless.yml:
custom:
test:
project: xxx
prod:
project: yyy
provider:
...
stage: ${opt:stage, 'test'}
project: ${self:custom.${opt:stage, 'test'}.project}
environment:
${file(.env.${opt:stage, 'test'}.yml):}
package:
exclude:
- .env.*
.env.test.yml:
VARIABLE1: value1
VARIABLE2: value2
During deploy, pass --stage=prod or skip and test project will be deployed. Then in your JS code you can access ENV variables with process.env.VARIABLE1.

Answer 4

Set Lambda environment variables from JSON file ( using AWS CLI)
aws lambda update-function-configuration --profile mfa --function-name test-api --cli-input-json file://dev.json

Answer 5

I had this correct, but I was referencing the file incorrectly.
I don't see this in the docs, but passing a file to environment will include the files yaml file, and the above structure does work.