Queue service

API Definition

The send message API

To use the queue client to send a message, call function (example in Javascript):

const queueClient = require('queue-client');

queueClient.sendMessage(
    'walletCreated', 
    {
        walletId: '1234',
        createdAt: '2021-01-01'
    }
);

## The receive message API

To use the queue client to receive a message, call function (example in Javascript):

```javascript
const queueClient = require('queue-client');

queueClient.receiveMessage(
    'walletCreated', 
    (message, acknowlege) => {
        console.log(message);
        acknowlege({
            acknowledged: true,
        });
    }
);

Note:

The user of this client decides whether or not to acknowledge the message by calling the callback function acknowlege.

The message should include the ack field which is the jsonb data in db, so the user of this client can choose to modify the existing ack or simply overwrite it.

Database Schema

The queue service use the database schema: 'queue'.

Tables:

• message

  Columns:

  • id: UUID
  • channel: text
  • data: jsonb
  • created_at: timestamptz
  • updated_at: timestamptz
  • ack: jsonb

Note, the act time could be record in ack column, like this:

{ acknowledgedByClientA: {ack: true, timestamp: 2023-03-15 18:37:06.880169-11} acknowledgedByClientB: {ack: true, timestamp: 2023-03-15 18:37:06.880169-11} }

Development toolkit

This repository was created from Greenstand's template for microservice projects. This means it comes with many development tools that we use for development and deployment. As a contributor to this repository, you should learn and use these tools. They are outlined below.

db-migrate

db-migrate is used to create database tables and other database objects

Conventional Commits

https://www.conventionalcommits.org/en/v1.0.0/

husky

husky will check commit messages to make sure they follow the required format

prettier / lint

github actions

mocha

Getting Started

Project Setup

Open terminal and navigate to a folder to install this project:

git clone https://github.com/Greenstand/treetracker-repository-name.git

Install all necessary dependencies:

npm install

Generate Initial Code:

cd scripts
sh generate-resource.sh

The above commands would generate an initial set of endpoints for the resource using our defined code structure

Default development environment setup

1. Ask engineering leads for a doctl dev token

2. Install doctl command line tool

• MacOS: brew install doctl

3. ./scripts/setup-dev-database-passwords.sh

Update an existing API to support ./scripts/setup-dev-database-passwords

1. Copy .env.*.example to API root folder
2. Copy database/database.json.example to API database folder
3. Copy scripts folder to API root folder
4. Set scripts/vars.sh to have the corret schema name

Localhost database Setup

This repository using db-migrate to manage database migrations for its schema.

cd database/
db-migrate --env dev up

If you have not installed db-migrate globally, you can run:

cd database/
../node_modules/db-migrate/bin/db-migrate --env dev up

Documentation for db-migrate: https://db-migrate.readthedocs.io/en/latest/

Architecture of this project

Our microservices use multiple layer structure to build the whole system. Similar with MVC structure:

Handler

• HTTP Domain
• All error and success codes
• API payload validation
• Calls a service or a model function

Service

• Orchestration between services and the domain model
  • Database session
  • External APIs
  • Cloud Services (such as RabbitMQ or S3)

Model

• Domain logic
• Accesses repositories

Repository

• Accesses the database, performs CRUD operations
• One repository for each database table in RDMS

How to test

Unit test

To run the unit tests:

npm run test-unit

Integration test

All the integration tests are located under folder __tests__

To run the integration test:

Run tests:

npm run test-integration

Database seeding test

In order to efficiently run our integration tests, we rely on automated database seeding/clearing functions to mock database entries. To test these functions, run:

npm run test-seedDB

Suggestion about how to run tests when developing

There is a command in the package.json:

npm run test-watch

By running test with this command, the tests would re-run if any code change happened. And with the bail argument, tests would stop when it met the first error, it might bring some convenience when developing.

NOTE: There is another command: test-watch-debug, it is the same with test-watch, except it set log's level to debug.

Postman

Can also use Postman to test the API manually.

To run a local server with some seed data, run command:

npm run server-test

This command would run a API server locally, and seed some basic data into DB (the same with the data we used in the integration test).