DrawTogether.NET

A collaborative browser-based drawing program written in .NET. Think of it like "multi-player MS paint."

Architecture and Motivation

Want to understand how DrawTogether was built and how it works? Please see our videos on the subject:

• Building Real-Time Web Applications with Blazor and Akka.NET
• Application Design with Actors Made Easy: Think Locally, Act Globally

Running Locally

First things first, you will need to launch the dependencies for DrawTogether.NET - make sure you have docker installed locally - the easiest way to do this is with .NET Aspire:

dotnet run --project src/DrawTogether.AppHost/DrawTogether.AppHost.csproj

This will:

• Start the SQL Server database
• Run the migration service to initialize the database
• Launch the DrawTogether web application
• Open the Aspire dashboard in your browser

The Aspire dashboard will show you all running services with their statuses and endpoints.

Entity Framework Core Migrations

If you need to apply a change to the database model, by default this project uses the SQL Server 2022 launched in the step above. To apply migrations, change your directory to the DrawTogether project:

cd ./src/DrawTogether/

And then apply the migrations:

dotnet ef database update

To generate a migration script that you can apply manually (later):

dotnet ef migrations script

MailGun Configuration

DrawTogether.NET can use MailGun to send outbound emails (via FluentEmail.Mailgun) - and the following two secrets need to be configured in order for that sending to work:

cd ./src/DrawTogether/
dotnet user-secrets set "EmailSettings:MailgunDomain" "<mailgun-domain>"
dotnet user-secrets set "EmailSettings:MailgunApiKey" "<mailgun-api-key>"

If these settings are not provided, DrawTogether.NET will simply fall back to not having email available to support ASP.NET Core Identity.

Deployment

Out of the box DrawTogether.NET supports Kubernetes deployments, however, if you want to run it locally you'll need to make sure that you have Nginx Ingress enabled.

This is how to deploy the most recent version of Nginx Ingress on Docker Desktop at the time of writing this:

kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.10.1/deploy/static/provider/cloud/deploy.yaml

Next, you will need to build a local Docker image:

dotnet publish src/DrawTogether/DrawTogether.csproj --os linux --arch x64 -c Release -p:PublishProfile=DefaultContainer

This will tag a local Docker image with the following labels:

• drawtogether-app:latest
• drawtogether-app:{VERSION}

Update the k8s-web-service.yaml to use the drawtogether-app:{VERSION} label - if you try to use the drawtogether-app:latest Kubernetes will attempt to pull the latest image from Docker Hub.

Finally, launch everything via the ./k8s/deployAll.cmd - and DrawTogether should be available at http://drawtogether.localdev.me