This post walks through how to orchestrate Keycloak, Platform, and Portal applications using .NET Aspire — complete with OpenTelemetry integration, configurable RUN_MODE, and a flexible multi-project structure that scales from infra-only to a full stack.

1. Setting up the Infra layer

Start by preparing your .NET and Aspire projects:

# Set SDK version
dotnet new globaljson --sdk-version 9.0.304

# Aspire orchestration projects
dotnet new aspire-apphost -n AppHost -o infra/aspire/AppHost -f net9.0
dotnet new aspire-servicedefaults -n ServiceDefaults -o infra/aspire/ServiceDefaults -f net9.0

2. Backend services

We’ll define two web APIs — Platform and Portal — both using shared authentication logic via Keycloak.

dotnet new webapi -n Platform -o services/backend/Platform -f net9.0 --use-controllers
dotnet new webapi -n Portal   -o services/backend/Portal   -f net9.0 --use-controllers

dotnet add services/backend/Platform/Platform.csproj reference infra/aspire/ServiceDefaults/ServiceDefaults.csproj
dotnet add services/backend/Portal/Portal.csproj   reference infra/aspire/ServiceDefaults/ServiceDefaults.csproj

dotnet add infra/aspire/AppHost/AppHost.csproj reference services/backend/Platform/Platform.csproj
dotnet add infra/aspire/AppHost/AppHost.csproj reference services/backend/Portal/Portal.csproj

# Shared authentication library
mkdir -p services/backend/_shared/Common.Auth
dotnet new classlib -n Common.Auth -f net9.0 -o services/backend/_shared/Common.Auth
dotnet add services/backend/Platform/Platform.csproj reference services/backend/_shared/Common.Auth/Common.Auth.csproj
dotnet add services/backend/Portal/Portal.csproj   reference services/backend/_shared/Common.Auth/Common.Auth.csproj

3. RUN_MODE: controlling what to launch

Your RUN_MODE variable defines which part of the system Aspire starts.
Examples:

Mode	Description
infra-only	Only observability + databases + Keycloak
platform:be	Platform backend only
platform:be+fe	Platform backend + frontend
platform:be,portal:be+fe	Platform backend + Portal stack
platform:be+fe,portal:be+fe	Full stack

Continue reading “Running Keycloak with Observability and Multi-App Orchestration in .NET Aspire” →