TL;TR

The goal of this project is to present the learning of the course Service Design and Engineering. The requirements are to develop a project that consists of multiple microservices and use techniques and technologies presented during the course. The idea of the project is an application where the user can create wishlists, and invites other persons to buy an item from that wishlist via email. The content of a wishlist is based on a vendor wishlist (e.g. Amazon.com). To make a wishlist available, the application extracts the content from a given wishlist URL and saves it in a structured format to the database.

Design

This chapter describes the architecture and database design.

Architecture

The figure illustrates the architecture of the application. It consists of four different layers, each serving a different purpose. Each layer (except the Data Layer) includes services that are designed to solve a specific task and be self-describing and self-continued. The architecture is designed as a choreography. No service takes responsibility for the whole process and services are aware of collaborating.

Database

Figure 2 illustrates the UML diagram of the database model. There exist two models, a user, and an item. A single user owns multiple items. To simplify the database model, an item can only be owned by a single user. A user only exists of an ID that identifies a user and is unique for each one. The User-Service creates new user instances and randomly creates a UUIDv4 for a new user. An item is identified by its ID. Furthermore, the item model also saves the vendor ID which refers to the ID that was given by the vendor. Important to mention is also the has been bought property, the reason why an item can only be owned by a single user. It represents if an item has been bought by a buyer or not.

Documentation

• User-Endpoint
  • API
  • Usage
• User-Service
  • API
  • Usage
• Mail-Service
  • API
  • Usage
• Scrapper-Facade
  • API
  • Usage
• Database-Adapter
  • API
  • Usage
• GMail-Adapter
  • API
  • Usage
• Amazon-Adapter
  • API
  • Usage

Generate HTML decoumentation

You will find a script called genHtml.sh in docs/. This will transform all .apib files in the folder into .html files using Aglio.

$ cd docs/
$ ./genHtml.sh

Usage

Set up

Go workspace

To simplify working with this multi-module application, Go workspaces come in handy. It can be initialized using the following command:

$ go work use utils \
    user-endpoint \
    user-service \
    mail-service \
    scrapper-facade \
    database-adapter \
    gmail-adapter

Add wishlists

The Amazon-Clone requires some wishlists exported from Amazon.com. You can open a wishlist on Amazon and save it using your browser. Then, save the content to amazon-clone/nginx/hz/wishlist/ls/WISHLIST-ID.

The ID is visible via the URL. For example, if your wishlist URL is https://www.amazon.com/hz/wishlist/ls/194N1KF03IPTL/, the ID is 194N1KF03IPTL.

JWT

For authentication purposes, a JWT token is necessary. You can create a random secret at https://bitwarden.com/password-generator/.

Save the secret at /env/JWT.env.

JWT_SIGN_KEY=THIS-IS-THE-RANDOM-SECRET

Google-Mail

To send mails via the Google-Mail SMTP server an app password is necessary. This is explained at https://support.google.com/mail/answer/185833?hl=en. Save your GMail address and the app password at /env/gmail-adapter/.env.

[email protected]
GMAIL_PASSWORD=THE-APP-PASSWORD

Run

This project uses Podman to run all services in a container. A docker-compose.yml file exists in the root directory of the project, that can be used with podman-compose to start the whole multi-service application. After that, the User-Endpoint is available at http://localhost:8080.

$ sudo podman-compose up --build

After that, you can delete all builder images using:

$ sudo podman image prune --filter label=stage=builder

You can also use podman-compose to build and run a specific collection of services.

$ sudo podman-compose up --build database-adapter database

Important to mention: By default only the User-Endpoint and Amazon-Clone are accessible through the outside. If you wanto to test/access specific services using Podman, you have to publish its ports in the docker-compose.yml.

Testing

To test this project, a Postman collection is provided at /Wishlist-Inviter.postman_collection.json.

License

Creative Commons Attribution 4.0 International Public License