Evaluate replacing Docker/ACR deployment with native App Service runtime deployment

[prasadhonrao]

Summary

The current App Service deployment pipeline follows this flow:

Build Docker image → Push to Azure Container Registry (ACR) → Deploy container to App Service

Azure App Service natively supports all runtimes used in this project:

Service	Runtime	App Service Runtime
Node.js services	Node.js 20	NODE|20-lts
Python services	Python 3.12	PYTHON|3.12
.NET services	.NET 8	DOTNETCORE|8.0
Java services	Java 21 / Spring Boot	JAVA|21-java21

This raises the question: should we switch to native runtime (zip) deployment using az webapp deploy, eliminating the Docker/ACR dependency entirely?

Potential Benefits

• Simpler pipeline — No Docker build step, no ACR, no image push
• Lower cost — ACR has a monthly fee; native deployment has none
• Faster deployments — Zip deploy is significantly faster than building and pushing container images
• No Docker on CI agents — Reduces CI/CD agent requirements
• Managed runtime patching — App Service handles OS and runtime security patches automatically

Trade-offs to Assess

• Environment parity — Docker gives identical environments locally and in Azure. Native runtime relies on App Service's managed runtime, which may differ subtly from local
• Custom startup complexity — Some services have non-trivial startup configuration (gunicorn workers, dumb-init, multi-stage builds) that's cleanly expressed in Dockerfiles but would need App Service startup command strings instead
• Polyglot consistency — With 4 different runtimes, containers provide one uniform deployment mechanism; native runtime requires runtime-specific handling per technology
• Rollback — ACR stores tagged images enabling precise rollback; zip deploy rollback is less straightforward
• Dependency control — Dockerfiles pin exact dependency versions; native runtime inherits whatever App Service provides for that runtime version

Recommendation to Evaluate

A hybrid approach may be optimal:

• Frontend UIs (customer-ui, admin-ui) — Static React builds are ideal for zip deploy or Azure Static Web Apps; no reason to run a container
• Backend services — Keep containers for environment parity and startup control, or switch to native if simplicity is the priority

Related

• Current deployment scripts: infrastructure/azure/app-service/bash/services/
• Common deployment function: deploy_service_full in services/_common.sh