Doppler System Usage

It is a simple HTTP API that allows Doppler client side services to register what features the user access to, and expose a summary.

This is our first production Doppler service based on Node.js running on AWS Lambda and API Gateway using the Serverless Framework.

See https://github.com/FromDoppler/aws-node-http-api-project for details about related POC.

Manual setup

Buckets

For the moment, we decided to share a bucket for all lambda functions in the same environment, so we have three:

• doppler-fun-int-us-east-2
• doppler-fun-qa-us-east-2
• doppler-fun-production-us-east-2

Each of them has been created manually using the S3 Buckets page.

Custom domain

We are using a custom domain for each environment:

• {custom-domain}.fromdoppler.com/lambdas-poc/ ➡ lambdas-poc-production API
• {custom-domain}qa.fromdoppler.net/lambdas-poc/ ➡ lambdas-poc-qa API
• {custom-domain}int.fromdoppler.net/lambdas-poc/ ➡ lambdas-poc-int API

Our custom domain is managed by Cloudflare.

Step by step configuration

1. Create a certificate

2. Validate certificate

3. Create custom domain in AWS

4. Add DNS to the custom domain

5. Configure mappings

Now it is done by code 😀

Usage

Deployment

$ serverless deploy

After deploying, you should see output similar to:

Deploying doppler-system-usage to stage dev (us-east-1)

✔ Service deployed to stack doppler-system-usage-dev (152s)

endpoint: GET - https://xxxxxxxxxx.execute-api.us-east-2.amazonaws.com/
functions:
  hello: doppler-system-usage-dev-hello (1.9 kB)

Invocation

After successful deployment, you can call the created application via HTTP:

curl https://xxxxxxx.execute-api.us-east-2.amazonaws.com/

Which should result in response similar to the following (removed input content for brevity):

{
  "message": "Go Serverless v2.0! Your function executed successfully!",
  "input": {
    ...
  }
}

Local development

You can invoke your function locally by using the following command:

serverless invoke local --function hello

Which should result in response similar to the following:

{
  "statusCode": 200,
  "body": "{\n  \"message\": \"Go Serverless v3.0! Your function executed successfully!\",\n  \"input\": \"\"\n}"
}

Alternatively, it is also possible to emulate API Gateway and Lambda locally by using serverless-offline plugin, you can start local emulation with:

serverless shn run-offline.sh

To learn more about the capabilities of serverless-offline, please refer to its GitHub repository.