Accessing environment configs defined in serverless.yaml in standalone nodejs script

Question

I have recently started working on a project in which we are using serverless framework. We are using docker to make dev environment easier to setup.

As part of this docker setup we have created a script that creates S3 buckets & tables among other things. We were earlier defining environment variables in the docker-compose file and were accessing them in our nodejs app. For purposes of deployment to other environments our devops team defined a few environment variables in the serverless.yaml file resulting in environment configs being present at two places. We are now planning to move all the environment configs defined in our docker-compose file to serverless.yaml. This works well for our lambdas functions as they are able to read these configs, but it doesn't work for the standalone setup script that we have written.

I tried using this plugin(serverless-scriptable-plugin) in an attempt to be able to read these env variables but still unable to do so.

Here is my serverless.yaml file

service:
  name: my-service

frameworkVersion: '2'
configValidationMode: error

provider:
  name: aws
  runtime: nodejs14.x
  region: 'us-east-1'
  profile: ${env:PROFILE, 'dev'}
  stackName: stack-${self:provider.profile}
  apiName: ${self:custom.environment_prefix}-${self:service.name}-my-api
  environment: ${self:custom.environment_variables.${self:provider.profile}}

plugins:
  - serverless-webpack
  - serverless-scriptable-plugin
  - serverless-offline-sqs
  - serverless-offline

functions:
  myMethod:
    handler: handler.myHandler
    name: ${self:custom.environment_prefix}-${self:service.name}-myHandler
    events:
      - sqs:
          arn:
            Fn::GetAtt:
              - MyQueue
              - Arn

resources:
  Resources:
    MyQueue:
      Type: AWS::SQS::Queue
      Properties:
        QueueName: ${self:custom.queuename}
        Tags:
          - Key: product
            Value: common
          - Key: service
            Value: common
          - Key: function
            Value: ${self:service.name}
          - Key: region
            Value: ${env:REGION}

package:
  individually: true

custom:
  webpack:
    webpackConfig: ./webpack.config.js
    includeModules: true
  serverless-offline:
    host: 0.0.0.0
    port: 3000

  serverless-offline-sqs:
    apiVersion: '2012-11-05'
    endpoint: http://sqs:9324
    region: ${self:provider.region}
    accessKeyId: root
    secretAccessKey: root
    skipCacheInvalidation: false

  localstack:
    stages:
      - local
    lambda:
      mountCode: true
    debug: true

  environment_prefixes:
    staging: staging
    production: production
    dev: dev
  environment_prefix: ${self:custom.environment_prefixes.${self:provider.profile}}
  queuename: 'myQueue'

  environment_variables:
    dev:
      AWS_ACCESS_KEY_ID: test
      AWS_SECRET_ACCESS_KEY: test
      BUCKET_NAME: my-bucket
      S3_URL: http://localstack:4566
      SLS_DEBUG: '*'

  scriptable:
    commands:
      setup: node /app/dockerEntrypoint.js

In my DockerFile I try executing script using sls setup CMD. I initially thought using sls command might expose these environment variables defined in serverless.yaml file but it doesn't seem to happen.

Is there any other way this can be achieved? I am trying to access these variables using process.env which works for lambdas but not for my standalone script. Thanks!

score 1 · Answer 1 · answered Aug 04 '21 at 22:39

There's not a good way to get access to these environment variables if you're running the lambda code as a script.

The Serverless Framework injects these variables into the Lambda function runtime configuration via CloudFormation.

It does not insert/update the raw serverless.yml file, nor does it somehow intercept calls to process.env via the node process.

You'll could use the scriptable plugin to run after package, and then export each variable into your local docker environment. But that seems pretty heavy for the variables in your env.

Instead, you might consider something like dotenv, which will load variables from a .env file into your environment.

There is a serverless-dotenv plugin you could use, and then your script could also call dotenv before running.

Thanks for your response. I think this is the only way we can proceed. I initially thought the using scriptable plugin serverless might inject the env variables into the context when executing my standalone script. — abhinav, Aug 04 '21 at 23:18
It could, but you'd have to write that logic yourself. It's probably easier to just use `nodenv` instead. — Aaron Stuyvenberg, Aug 05 '21 at 13:19

Accessing environment configs defined in serverless.yaml in standalone nodejs script

1 Answers1