Tracing a Serverless Application

Recap.dev provides two levels of tracing: basic tracing and function-level tracing

Basic tracing collects request, response and error information, logs and provides a timeline of external resource access (databases, http endpoints, external services) of your unit (basically, endpoint or handler).

Function-level tracing also adds timings of the individual function calls to the timeline.

Setting up a Basic Tracing#

Recap.dev currently supports tracing of Serverless Framework out of the box. It's also easy to setup tracing for applications not using Serverless Framework.

Serverless Framework#

To use recap.dev with the Serverless Framework all you need to do is to add recap.dev serverless plugin and configure it.

1. Install recap.dev serverless plugin#

yarn add --dev @recap.dev/serverless-plugin

npm i --save-dev @recap.dev/serverless-plugin

2. Install recap.dev client library#

yarn add @recap.dev/client

npm i --save @recap.dev/client

3. Add recap.dev plugin to your serverless.yml#

Please note that recap.dev plugin should be the first plugin in the list.

plugins:
  - "@recap.dev/serverless-plugin"

4. Add `RECAP_DEV_SYNC_ENDPOINT` environment variable#

It should point to your recap.dev server installation.

provider:
  environment:
    RECAP_DEV_SYNC_ENDPOINT: http://recap-dev.company.com:8080/traces

After doing this and redeploying you should start getting tracing data with basic details.

Check out an example project here.

Applications Not Using Serverless Framework#

Almost any serverless application can be easily traced with recap.dev even when not using Serverless Framework.

1. Install recap.dev client library#

yarn add @recap.dev/client

npm i --save @recap.dev/client

2. Wrap Your Handler Function with Recap.Dev#

Use wrapLambdaHandler exported from the @recap.dev/client package like this:

import { wrapLambdaHandler } from '@recap.dev/client'

export const handler = wrapLambdaHandler(async () => {
  const response = await fetch('https://cat-fact.herokuapp.com/facts')
  return response.json()
})

3. Add `RECAP_DEV_SYNC_ENDPOINT` environment variable#