Serverless Docker options

Same image: $DOCKERHUB_USERNAME/email-link-host

Platform	Port	Notes
Fly.io	internal 8080	fly launch / fly deploy with Dockerfile or image
Railway	set PORT/ADDR	Deploy from Docker Hub image
Render	Web Service	Docker runtime
Google Cloud Run	$PORT	Map container port 8080; set env
AWS App Runner	8080	From ECR or public Docker Hub
Azure Container Apps	8080	Ingress external

Go listens on ADDR (default :8080) or PORT.

Cloud Run example

gcloud run deploy email-link-host \
  --image=$DOCKERHUB_USERNAME/email-link-host:latest \
  --platform=managed \
  --allow-unauthenticated \
  --port=8080 \
  --set-env-vars="SITE_BRAND=MyApp,ANDROID_STORE_URL=https://..."

Prefer secret managers for sensitive values in production.