Azure Container Apps - Java Todo API

A Quarkus-based Todo API deployed to Azure Container Apps using Terraform and Azure Developer CLI (azd).

Architecture

┌────────────────────────────────────────────────────────────────┐
│                        Azure Resource Group                    │
│                                                                │
│  ┌──────────────────┐    ┌──────────────────────────────────┐  │
│  │ Container        │    │ Container Apps Environment       │  │
│  │ Registry (ACR)   │───▶│                                  │  │
│  └──────────────────┘    │  ┌─────────────────────────────┐ │  │
│                          │  │ Backend Container App       │ │  │
│                          │  │ (Quarkus Todo API)          │ │  │
│                          |  |                             | |  |
│                          │  └─────────────────────────────┘ │  │
│                          └──────────────────────────────────┘  │
│                                         │                      │
│                                         ▼                      │
│                          ┌──────────────────────────────────┐  │
│                          │ PostgreSQL Flexible Server       │  │
│                          │ - Database: todo                 │  │
│                          └──────────────────────────────────┘  │
│                                                                │
│  ┌──────────────────────────────────────────────────────────┐  │
│  │ Log Analytics Workspace                                  │  │
│  └──────────────────────────────────────────────────────────┘  │
└────────────────────────────────────────────────────────────────┘

Prerequisites

• Azure CLI
• Azure Developer CLI (azd)
• Terraform >= 1.0
• Docker
• Java 21 (for local development)
• Maven (for local development)

Project Structure

.
├── azure.yaml                 # Azure Developer CLI configuration
├── infra/                     # Terraform infrastructure
│   ├── main.tf               # Main configuration using modules
│   ├── variables.tf          # Input variables
│   ├── outputs.tf            # Output values
│   ├── main.tfvars.json      # azd parameter file
│   └── modules/              # Terraform modules
│       ├── resource-group/   # Resource group module
│       ├── container-registry/# ACR module
│       ├── postgresql/       # PostgreSQL module
│       └── container-apps/   # Container Apps module
└── src/
    └── backend/              # Quarkus application
        ├── Dockerfile
        ├── pom.xml
        └── src/
            └── main/
                ├── java/     # Java source code
                └── resources/# Application configuration

Quick Start

1. Login to Azure

azd auth login

2. Build the Application Locally

cd src/backend
./mvnw package -DskipTests
cd ../..

3. Deploy to Azure

azd up

This command will:

1. Prompt for environment name and Azure location
2. Provision all Azure resources using Terraform
3. Build and push the Docker image to ACR
4. Deploy the application to Container Apps

4. Access the Application

After deployment, the API will be available at the URL shown in the output:

BACKEND_URI = "https://backend.<unique-id>.azurecontainerapps.io"

API Endpoints

Method	Endpoint	Description
GET	/api/todos	List all todos
POST	/api/todos	Create a new todo

Example Usage

# Get all todos
curl https://backend.<unique-id>.azurecontainerapps.io/api/todos

# Create a todo
curl -X POST https://backend.<unique-id>.azurecontainerapps.io/api/todos \
  -H "Content-Type: application/json" \
  -d '{"description": "Learn Azure", "details": "Deploy apps to ACA"}'

Infrastructure Modules

resource-group

Creates an Azure Resource Group to contain all resources.

container-registry

Provisions Azure Container Registry (ACR) for storing Docker images.

postgresql

Deploys Azure Database for PostgreSQL Flexible Server with:

• Auto-generated secure password
• Firewall rule for Azure services
• Database named todo

container-apps

Creates the Container Apps environment and application with:

• Log Analytics workspace for monitoring
• Ingress configuration for external access
• Environment variables for database connection
• Auto-scaling (0-3 replicas)

Local Development

Run PostgreSQL locally

docker run -d \
  --name postgres \
  -e POSTGRES_PASSWORD=postgres \
  -e POSTGRES_DB=todo \
  -p 5432:5432 \
  postgres:16

Run the application

cd src/backend
./mvnw quarkus:dev

The API will be available at http://localhost:8080/api/todos

Environment Variables

Variable	Description	Default
QUARKUS_DATASOURCE_JDBC_URL	PostgreSQL connection URL	jdbc:postgresql://localhost:5432/todo
QUARKUS_DATASOURCE_USERNAME	Database username	postgres
QUARKUS_DATASOURCE_PASSWORD	Database password	postgres
QUARKUS_HIBERNATE_ORM_DATABASE_GENERATION	Schema generation strategy	drop-and-create (dev) / update (prod)

Commands Reference

# Deploy everything
azd up

# Provision infrastructure only
azd provision

# Deploy application only (after code changes)
azd deploy

# View deployed resources
azd show

# Tear down all resources
azd down

# View logs
azd monitor --logs

Troubleshooting

Build fails with Java version error

Ensure you're using Java 21:

java -version
export JAVA_HOME="/opt/homebrew/opt/openjdk@21/libexec/openjdk.jdk/Contents/Home"

Container App fails to start

Check the logs:

az containerapp logs show \
  --name backend \
  --resource-group <resource-group> \
  --follow

Database connection issues

Verify the PostgreSQL firewall allows Azure services:

az postgres flexible-server firewall-rule list \
  --resource-group <resource-group> \
  --name <server-name>

Clean Up

To delete all Azure resources:

azd down

License

MIT