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Prerequisites This article builds on the prior article: Patch. Tracking History The way our service is currently built, all modifications (PATCH requests) happen in-place to records in DynamoDB. It is common in most production applications that someone will want to know the history of a record. A business user may want to know who changed...

Prerequisites This article builds on the prior article: Node Reference - Get Product by Id. Supporting Updates Sooner or later, there will be a need to modify a product. Except in the case of immutable data stores, rarely are there entities that are truely "insert only". In order to support this, we need...

Prerequisites This article builds on the prior article: Node Reference - Listing. Add Get By Id At this point, we have only one way to get Products. We have to list all products and page through them to find the one we want. However, a lot of the time, a RESTful service client will have...

Prerequisites This article builds on the prior article: Node Reference - Monitoring. Add listing Clients of our service will need a way to find products. For that, we need a product listing service. DynamoDB provides an operation for listing the contents of a table called a 'scan'. (As a table or index grows,...

Monitoring How do we answer the question: "Is our application performing correctly?" With just one application server we could remotely log into the server, look at CPU and memory load, run grep{:target="_blank"} on the log files and then determine that everything is fine. This approach is manual intensive and obviously does not scale...

Prerequisites This article builds on the prior article: Node Reference - Validation. Add Integration or Smoke Tests So far, our testing strategy has consisted of only Unit Testing{:target="_blank"}, testing each module in isolation. While this type of testing covers most business logic, it does leave some gaps. It does not test that our modules interact...

Prerequisites This article builds on the prior article: Node Reference - Put. Add model validation We now have a service that allows us to create product records but does not provide any mechanism for ensuring those products contain all the required data we need in the correct format. For this, we need data...

Prerequisites This article builds on the prior article: Node Reference - DynamoDB. Create put test/endpoint First, lets write a spec for our POST /products endpoint. Create a file called products/createProduct.spec.js with the following contents: const proxyquire = require('proxyquire'); describe('products', function () { describe('createProduct', function () { ...

Prerequisites This article builds on the prior article: Node Reference - Authentication. Add DynamoDB Before we can start building out our product endpoints, we need a place to store them. For that, we are turning to DynamoDB{:target="_blank"}. Tables are the main component, not a "database", so we can create just a single table....

Prerequisites This article builds on the prior article: Node Reference - Cognito. Adding authentication In order to leverage our new identity provider, we need to add a middleware into our Koa pipeline. This middleware will reject requests that do not contain valid tokens. We can accomplish this by using two libraries: koa-jwt{:target="_blank"} to validate...