hmpps-template-typescript

Template github repo used for new Typescript based projects.

Instructions

If this is a HMPPS project then the creation of new services is automated and cloning/forking this repository is not required.

Documentation to create new services is located here.

This project is community managed by the mojdt #typescript slack channel. Please raise any questions or queries there. Contributions welcome!

Our security policy is located here.

More information about the template project including features can be found here.

Creating a Cloud Platform namespace

When deploying to a new namespace, you may wish to use the templates project namespace as the basis for your new namespace. This namespace contains both the kotlin and typescript template projects, which is the usual way that projects are setup. This namespace includes an AWS elasticache setup - which is required by this template project.

Copy this folder and update all the existing namespace references. If you only need the typescript configuration then remove all kotlin references. Submit a PR to the Cloud Platform team in #ask-cloud-platform. Further instructions from the Cloud Platform team can be found in the Cloud Platform User Guide

Customising the new project

As part of the automation to create the new service, various parts of the codebase will be updated to reflect it's specific name.

Oauth2 Credentials

The template project is set up to run with two sets of credentials, each one support a different oauth2 flows. These need to be requested from the auth team by filling in this template and raising on their slack channel.

Auth Code flow

These are used to allow authenticated users to access the application. After the user is redirected from auth back to the application, the typescript app will use the returned auth code to request a JWT token for that user containing the user's roles. The JWT token will be verified and then stored in the user's session.

These credentials are configured using the following env variables:

• AUTH_CODE_CLIENT_ID
• AUTH_CODE_CLIENT_SECRET

Client Credentials flow

These are used by the application to request tokens to make calls to APIs. These are system accounts that will have their own sets of roles.

Most API calls that occur as part of the request/response cycle will be on behalf of a user. To make a call on behalf of a user, a username should be passed when requesting a system token. The username will then become part of the JWT and can be used downstream for auditing purposes.

These tokens are cached until expiration.

These credentials are configured using the following env variables:

• CLIENT_CREDS_CLIENT_ID
• CLIENT_CREDS_CLIENT_SECRET

Dependencies

HMPPS Auth

To allow authenticated users to access your application you need to point it to a running instance of hmpps-auth. By default the application is configured to run against an instance running in docker that can be started via docker-compose.

NB: It's common for developers to run against the instance of auth running in the development/T3 environment for local development. Most APIs don't have images with cached data that you can run with docker: setting up realistic stubbed data in sync across a variety of services is very difficult.

REDIS

When deployed to an environment with multiple pods we run applications with an instance of REDIS/Elasticache to provide a distributed cache of sessions. The template app is, by default, configured not to use REDIS when running locally.

Running the app via docker-compose

The easiest way to run the app is to use docker compose to create the service and all dependencies.

docker compose pull

docker compose up

Running the app for development

To start the main services excluding the example typescript template app:

docker compose up --scale=app=0

Create an environment file by copying .env.example -> .env Environment variables set in here will be available when running start:dev

Install dependencies using npm install, ensuring you are using node v20

Note: Using nvm (or fnm), run nvm install --latest-npm within the repository folder to use the correct version of node, and the latest version of npm. This matches the engines config in package.json and the github pipeline build config.

And then, to build the assets and start the app with esbuild:

npm run start:dev

Logging in with a test user

Once the application is running you should then be able to login with:

username: AUTH_USER password: password123456

To request specific users and roles then raise a PR to update the seed data for the in-memory DB used by Auth

Run linter

• npm run lint runs eslint.
• npm run typecheck runs the TypeScript compiler tsc.

Run unit tests

npm run test

Running integration tests

For local running, start a wiremock instance by:

docker compose -f docker-compose-test.yml up

Then run the server in test mode by:

npm run start-feature (or npm run start-feature:dev to run with auto-restart on changes)

And then either, run tests in headless mode with:

npm run int-test

Or run tests with the cypress UI:

npm run int-test-ui

Change log

A changelog for the service is available here