Example Voting App
A simple distributed application running across multiple Docker containers.
Getting started
Download Docker Desktop for Mac or Windows. Docker Compose will be automatically installed. On Linux, make sure you have the latest version of Compose.
Linux Containers
The Linux stack uses Python, Node.js, .NET Core (or optionally Java), with Redis for messaging and Postgres for storage.
Run in this directory:
docker-compose up
The app will be running at http://localhost:5000, and the results will be at http://localhost:5001.
Run the app in Kubernetes
The folder k8s-specifications contains the yaml specifications of the Voting App's services.
First create the vote namespace
$ kubectl create namespace vote
Run the following command to create the deployments and services objects:
$ kubectl create -f k8s-specifications/
deployment "db" created
service "db" created
deployment "redis" created
service "redis" created
deployment "result" created
service "result" created
deployment "vote" created
service "vote" created
deployment "worker" created
The vote interface is then available on port 31000 on each host of the cluster, the result one is available on port 31001.
Architecture
- A front-end web app in Python or ASP.NET Core which lets you vote between two options
- A Redis or NATS queue which collects new votes
- A .NET Core, Java or .NET Core 2.1 worker which consumes votes and stores them in…
- A Postgres or TiDB database backed by a Docker volume
- A Node.js or ASP.NET Core SignalR webapp which shows the results of the voting in real time
Note
The voting application only accepts one vote per client. It does not register votes if a vote has already been submitted from a client.