Spring Boot to Azure Container Apps Migration
Migrate Spring Boot applications from Azure Spring Apps, VMs, or other platforms to Azure Container Apps with containerization, deployment, and Spring Cloud integration.
Overview
This migration enables you to move existing Spring Boot applications from Azure Spring Apps (or any platform) to Azure Container Apps with minimal code changes.
Migration Scenarios
| Source Platform | Target Platform | Migration Path |
|---|---|---|
| Azure Spring Apps | Azure Container Apps | Assess → Containerize → Deploy → Spring Cloud components |
| Spring Boot on VMs | Azure Container Apps | Assess → Containerize → Deploy |
| Spring Boot (other cloud) | Azure Container Apps | Assess → Containerize → Deploy |
Service Mapping
| Spring Apps Feature | Container Apps Equivalent |
|---|---|
| App Deployment | Container App |
| Service Registry (Eureka) | Managed Eureka for Spring (eureka-server-for-spring); alt: Dapr service invocation + internal DNS |
| Config Server | Managed Config Server for Spring (config-server-for-spring); alt: Azure App Configuration + Key Vault |
| Spring Cloud Gateway | Managed Gateway for Spring; alt: Azure API Management / Container Apps ingress |
| Distributed Tracing | Application Insights |
| Log Streaming | Log Analytics Workspace |
Pre-Migration Assessment
Assess your Spring Boot application for migration readiness:
- Local State: Check for in-memory sessions, singletons, file-based state → spring-assessment-guide.md
- File System: Identify file writes, temp files, shared storage needs → spring-assessment-guide.md
- Platform Compatibility: Verify Java 17+, Spring Boot 3.x support → spring-assessment-guide.md
- External Resources: Inventory databases, message brokers, caches → spring-assessment-guide.md
Migration Workflow
- Assess — Analyze application for migration readiness
Present findings and complexity rating to user. Ask: "Assessment complete — proceed with containerization?"
- Containerize — Create Dockerfile, build image, push to ACR
- Provision — Create Container Apps environment, configure logging
- Deploy — Deploy container to Azure Container Apps
- Optimize — Add Spring Cloud components (Config, Eureka, Gateway)
See spring-deployment-guide.md for detailed phase-by-phase instructions.
Key Differences from Azure Spring Apps
| Aspect | Azure Spring Apps | Container Apps |
|---|---|---|
| Deployment Unit | JAR/WAR | Container Image |
| Service Discovery | Built-in Eureka | Managed Eureka component (or Dapr / DNS) |
| Configuration Management | Built-in Config Server | Managed Config Server component (or App Configuration) |
| Scaling | Auto-scaling | HTTP/CPU/Memory/Custom metrics |
| Networking | VNet injection | VNet integration + Internal ingress |
Best Practices
- Use managed identity for Azure resource access (no connection strings)
- Store secrets in Azure Key Vault, reference via environment variables
- Use Application Insights for observability
- Enable Log Analytics for centralized logging
- Use Azure Files for persistent storage if needed
Next Steps After Migration
After successful migration:
- Configure Spring Cloud components (optional)
- Set up CI/CD pipeline with GitHub Actions / Azure DevOps
- Configure custom domains and SSL certificates
- Implement autoscaling rules
- Hand off to
azure-preparefor infrastructure optimization