lambda-powertools-correlation-ids

A helper module for recording correlation IDs.

Main features:

• allows you to fetch, update, and delete correlation IDs

• respects convention for correlation IDs - i.e. x-correlation-

• Manually enable/disable debug logging (debug-log-enabled) to be picked up by other/downstream middleware

• allows you to store more than one correlation IDs, which allows you to correlate logs on multiple dimensions (e.g. by x-correlation-user-id, or x-correlation-order-id, etc.)

Getting Started

Install from NPM: npm install @buyerassist/dazn-lambda-powertools-correlation-ids

API

const CorrelationIds = require("@buyerassist/dazn-lambda-powertools-correlation-ids");

// automatically inserts 'x-correlation-' prefix if not provided
CorrelationIds.set("id", "12345678"); // records id as x-correlation-id
CorrelationIds.set("x-correlation-username", "theburningmonk"); // records as x-correlation-username

// Manully enable debug logging (debug-log-enabled)
CorrelationIds.debugLoggingEnabled = true;

const myCorrelationIds = CorrelationIds.get();
// {
//   'x-correlation-id': '12345678',
//   'x-correlation-username': 'theburningmonk',
//   'debug-log-enabled': 'true'
// }

CorrelationIds.clearAll(); // removes all recorded correlation IDs
CorrelationIds.replaceAllWith({
  // bypasses the 'x-correlation-' convention
  "debug-log-enabled": "true",
  "User-Agent": "jest test",
});

// Disable debug logging
CorrelationIds.debugLoggingEnabled = false;

In practice, you're likely to only need set when you want to record correlation IDs from your function.

The middleware, @buyerassist/dazn-lambda-powertools-middleware-correlation-ids, would automatically capture the correlation IDs from the invocation event for supported event sources:

• API Gateway (via HTTP headers)

• Kinesis (via the JSON payload)

• SNS (via message attributes)

• any invocation event with the special field __context__ (which is how we inject them with the Step Functions and Lambda clients below)

Whilst other power tools would use get to make use of the correlation IDs:

• @buyerassist/dazn-lambda-powertools-logger includes recorded correlation IDs in logs

• @buyerassist/dazn-lambda-powertools-http-client includes recorded correlation IDs as HTTP headers when you make a HTTP request

• @buyerassist/dazn-lambda-powertools-sns-client includes recorded correlation IDs as SNS message attributes when you publish a message to SNS (ie. SNS.publish)

• @buyerassist/dazn-lambda-powertools-kinesis-client injects recorded correlation IDs as part of the event payload when you publish event(s) to Kinesis (ie. Kinesis.putRecord and Kinesis.putRecords)

• @buyerassist/dazn-lambda-powertools-step-functions-client injects recorded correlation IDs as part of the payload when you start a Step Functions execution (ie. SFN.startExecution)

• @buyerassist/dazn-lambda-powertools-lambda-client injects recorded correlation IDs as part of the invocation payload when you invoke a Lambda function directly (ie. Lambda.invoke and Lambda.invokeAsync)