The Coffee Bar App

The demo application instrumented by OpenTelemetry framework.

Content

• deployments directory contains specific deployments templates files
• applications directory contains sources of the application
  • aws-lambdas - contains sources of the CheckSweets and Sweets AWS lambda functions
  • dotnet-core-calculator-svc - contains sources of the calculator-svc application
  • js-the-coffee-bar-ui-clicker - contains sources of the puppeteer which clicks on the frontend application
  • python-the-coffee-bar-apps - contains sources of the-coffee-lover, the-coffee-bar, the-coffee-machine and the-cashdesk applications
  • ruby-the-coffee-bar-apps - contains sources of machine-svc, coffee-svc and water-svc applications
  • the-coffee-bar-frontend - contains sources of the web UI application
• scripts - directory contains build scripts

Prerequisities

• Installed docker
• Installed docker-compose

How to build?

Execute the build script build_local_all.sh from scripts directory. The script is going to build all of the applications in the docker images. To run the application execute docker-compose up command in the dockerization directory.

Application Overview

The Coffee Bar is an application designed to test instrumentation possibilities using the OpenTelemetry framework. The application consists of several small services written in various languages, including Python, Ruby and ASP .NET Core.

Application flow

Like in the real italian coffee bar there is espresso and his fans. The coffee enthusiast role goes to the-coffee-bar-frontend web application or the-coffee-lover app (traffic simulator). the-coffee-bar is a small italian bar where the-coffee-machine and the-cashdesk are located. the-coffee-machine with her parts: machine-svc responsible for coffee preparation, coffee-svc responsible for providing coffee beans and water-svc responsible for water provision. The espresso coffee is not for free. Payment is handled by the-cashdesk. To be sure that the sum to be paid is correct, calculator-svc is present.

1. the-coffee-bar-frontend - The Coffee Bar user interface
2. the-coffee-lover is asking for espresso coffee by HTTP POST request with specific JSON to the-coffee-bar service.
3. the-coffee-bar is sending the HTTP POST request to the-coffee-machine which sends a request to machine-svc.
4. machine-svc calls coffee-svc and water-svc for ingredients and then prepares coffee.
5. When coffee is done the-coffee-bar is sending the payment request to the-cashdesk.
6. the-cashdesk application is querying postgres to get a coffee price and then sends a request to calculator-svc
7. calculator-svc is doing some simple mathematical operations.

• the-coffee-bar-frontend - NodeJS
• the-coffee-lover - Python
  • the-coffee-bar - Python
    • lambdas - Python
    • the-coffee-machine - Python
      • machine-svc - Ruby
        • coffee-svc - Ruby
        • machine-svc - Ruby
    • the-cashdesk - Python
      • calculator-svc - ASP .NET Core
      • postgres

Contact

In case of any issues please contact Mateusz 'mat' Rumian @ [email protected]