@seek/aws-codedeploy-hooks

Runtime helpers for working with AWS CodeDeploy Hooks.

Usage

isHttpHook

Whether the HTTP request originated from AWS CodeDeploy Hooks.

This can be used to customise smoke test handling. When recovering a system with unhealthy dependencies, it may be desirable to expedite recovery efforts by skipping pre-deployment checks, while continuing to run the checks as per usual on subsequent health check polling.

const smokeTest = (req: Request) => {
  if (process.env.SKIP_HOOK && isHttpHook(req)) {
    // Expedite deployment even if dependencies are unhealthy.
    return;
  }

  // Run dependency checks otherwise.
  return checkDependencies();
};

Checks for a user-agent header that starts with either:

• aws-codedeploy-hook-BeforeAllowTraffic/
• gantry-codedeploy-hook-BeforeAllowTraffic-

Compatible with Gantry v2.3.7 and newer.

isLambdaHook

Whether the Lambda invocation originated from AWS CodeDeploy Hooks.

This can be used to customise smoke test handling. When recovering a system with unhealthy dependencies, it may be desirable to expedite recovery efforts by skipping pre-deployment checks, while continuing to run the checks as per usual on subsequent health check polling.

const handler = (event: Event, ctx: Context) => {
  if (!Object.entries(event).length) {
    if (process.env.SKIP_HOOK && isLambdaHook(event, ctx)) {
      // Expedite deployment even if dependencies are unhealthy.
      return;
    }

    // Run dependency checks otherwise.
    return checkDependencies();
  }

  // Run application logic.
  // ...
};

Checks for:

• An empty event object
• A custom user-agent in context that starts with aws-codedeploy-hook-BeforeAllowTraffic/

smokeTest.koaMiddleware

A Koa middleware that executes a smoke test function to check whether the application is broadly operational and ready to serve requests.

The skipHook option skips synchronous validation of the smoke test function during pre-deployment checks from an AWS CodeDeploy hook. This may be used when a build needs to be expedited in a disaster recovery scenario or when a dependency is known to be unhealthy.

import { Env } from 'skuba-dive';
import Router from '@koa/router';
import logger from '@seek/logger';

const config = {
  skipHook: Env.boolean('SKIP_SMOKE', { default: false }),
};

const logger = createLogger();

export const router = new Router().get(
  '/smoke',
  smokeTest.koaMiddleware({ logger, skipHook: config.skipHook }, async () => {
    // Run dependency checks.
    await checkDependencies();
  }),
);

Uses isHttpHook under the hood.