Narwhal

This repository contains a miniature version of the infrastructure we run in OneOcean. We use this repo as a test during our hiring process.

It is a full web application, displaying a world map, and showing points where Navigational Warning from France are emitted.

Also, the api call /tracking/get provides a list of vessels positions in the system.

The goal is to provide a test canvas for any candidate to ask various tasks and questions while staying close enough to our real world needs. It contains 8 different components, using multiple applications, tools and languages.

This test framework is valid for any technical position, as it includes some infrastructure, web services, front-end application, ETL pipelines and more.

Structure

• Narwhal.App: Web application, built with Angular. It sits behind the reverse proxy and communicates with the service to get information. It displays a world map and some
• Narwhal.Database: A MongoDB storage used to store information collected through the ETL pipeline
• Narwhall.ETL: A simple ETL pipeline written in Python, reads a text file to extract information and stores it in the database
• Narwhal.Front: A reverse proxy sitting in fromt of all web endpoints, similar to a real infrastructure. Any application or service call will go through it. It uses Nginx
• Narwhal.Importer: A Powershell script used to import the text based file for processing using the ETL pipeline
• Narwhal.Messaging: A MQTT server (mosquitto) used to notify the service, and the application when new data is available
• Narwhal.Service: An ASP.NET Core web service written in C#. It exposes the database information and reacts when new data is available
• Narwhal.Tests: A test suite for this application, writte in Python

Two scripts are available inside of every service directory:

• start_local.bat: A batch used to quickly start the corresponding service locally on your machine
• start_docker.bat: A batch used to build a Docker image and run it on your machine

Scripts with the same name are available in the root directory to run the full service stack at once. Please note that the root start_docker.bat script will use Docker Compose.

Requirements

You will be able to run all the services only using Docker on your machine. As mentionned, we also provide a docker-compose.yml file.

To develop on this application locally, you will need:

• Powershell to run Narwhal.Importer
• Python 3+ to run Narwhal.ETL and Narwhal.Tests
• .NET Core 3.1 to run Narwhal.Service
• NodeJS 12+ to run Narwhal.App

Even though the scripts are only provided in .bat files, the services should not be platform dependent and should be usable on Linux or Mac.

Quick start guide

If you have Docker and Docker Compose on your machine, just run start_docker.bat in the root diretory to get everything running. If you don't have it installed or if you want to work on the solution, please follow the steps below.

First, make sure you have all the requirements from the above paragraph installed properly.

You should now be able to run the start_local.bat in the root directory of Narwhal. It will create 5 console windows (Narwhal.Database, Narwhal.Messaging, Narwhal.Service, Narwhal.App, Narwhal.Front). Go grab a coffee as the Angular App will need some time to build.

When the build is over, you should be able to hit http://127.0.0.1 in your browser and see an empty map, as the database is empty.

Then, you can start Narwhal.Importer by running its own start_local.bat, it will import data to the Playground/Storage directory. Last step, you can start Narwhal.ETL by running its own start_local.bat, it will process the data previously downloaded and insert it in the database.

By refreshing your browser, you should be able to see some points on the map.

FAQ

I get some error with ports not available / already allocated

Below is the list of used ports. Work needs to be done in order to modify the ports easily.

• Narwhal.Database on port 27017
• Narwhal.Messaging on port 1883
• Narwhal.App on port 6162
• Narwhal.Service on port 6161
• Narwhal.Front on port 80

X was not found / Node asks me to update the version

• Make sure all the dependencies are up to date, refer to the Requirements block above

Attribution

The MIT licensing is not applicable to the following resources, as they are considered as external resources with their own licensing available in the links below.

• Icon by Freepik from flaticon.com
• MongoDB downloaded from mongodb.com
• Nginx downloaded from nginx.org
• Mosquitto downloaded from mosquitto.org
• Fart downloaded from sourceforge.net/projects/fart-it
• Map tiles from openstreetmap.org