Web APIs

Wed, 21 Oct 2026 17:55:00 +0000

My backends are ASP.NET Core APIs, and every one of them meets the platform the same way. Heimdall’s API is the example throughout; Fortuna’s follows the same shape.

Concern	Choice
Framework	ASP.NET Core on .NET 10
Image	Multi-stage: the SDK to build, the ASP.NET runtime to run
Database	The host’s PostgreSQL, one database per environment
Configuration	Environment variables, from yggdrasil
Health	`/healthcheck`, probed by Docker, yggdrasil and the status API
Metrics	OpenTelemetry’s Prometheus exporter, on port 9464
Logs	Standard output, shipped to Loki
Checks	Tests and a Docker build in GitHub Actions

The image

The Dockerfile has two stages. The first restores and publishes with the .NET 10 SDK, copying the project files before the sources so a source-only change reuses the cached restore. The second copies the output onto the much smaller ASP.NET runtime image, and runs it as the image’s own non-root user:

OpenTelemetry on Artur Rios Lab

Web APIs

The image