Quarkus Flow Applications

Learn how to structure and configure Quarkus Flow applications to work with Data Index.

Overview

To integrate with Data Index, your Quarkus Flow application needs:

Structured logging enabled - Emit JSON events to stdout
Kubernetes deployment - Run in Kubernetes where FluentBit can collect logs
Proper configuration - Property files for different environments

Application Structure

A typical Quarkus Flow application has this structure:

my-workflow-app/
├── pom.xml
├── src/
│   ├── main/
│   │   ├── java/
│   │   │   └── com/example/
│   │   │       ├── workflows/
│   │   │       │   └── MyWorkflow.java      # Java DSL workflows
│   │   │       └── resources/
│   │   │           └── WorkflowResource.java # JAX-RS endpoints
│   │   └── resources/
│   │       ├── application.properties         # Common config
│   │       ├── application-kind.properties    # KIND local dev
│   │       ├── application-prod.properties    # Production runtime
│   │       └── workflows/                     # YAML workflows (optional)
│   └── test/
│       └── java/
│           └── com/example/
│               └── WorkflowTest.java

Required Dependencies

Add to your pom.xml:

<dependencies>
    <!-- Quarkus Flow runtime -->
    <dependency>
        <groupId>io.quarkiverse.flow</groupId>
        <artifactId>quarkus-flow</artifactId>
    </dependency>

    <!-- REST API -->
    <dependency>
        <groupId>io.quarkus</groupId>
        <artifactId>quarkus-rest-jackson</artifactId>
    </dependency>

    <!-- Health checks -->
    <dependency>
        <groupId>io.quarkus</groupId>
        <artifactId>quarkus-smallrye-health</artifactId>
    </dependency>
</dependencies>

Structured Logging Configuration

Data Index requires structured logging to capture workflow events. Add to application.properties:

# Application name
quarkus.application.name=my-workflow-app

# Structured logging (REQUIRED for Data Index)
quarkus.flow.structured-logging.enabled=true
quarkus.flow.structured-logging.events=workflow.*
quarkus.flow.structured-logging.include-workflow-payloads=true
quarkus.flow.structured-logging.include-task-payloads=false
quarkus.flow.structured-logging.timestamp-format=epoch-seconds
quarkus.flow.structured-logging.log-level=INFO

# Console handler for JSON events
quarkus.log.handler.console."FLOW_EVENTS_CONSOLE".enabled=true
quarkus.log.handler.console."FLOW_EVENTS_CONSOLE".format=%s%n

# Route structured logging to console
quarkus.log.category."io.quarkiverse.flow.structuredlogging".handlers=FLOW_EVENTS_CONSOLE
quarkus.log.category."io.quarkiverse.flow.structuredlogging".use-parent-handlers=false
quarkus.log.category."io.quarkiverse.flow.structuredlogging".level=INFO

See the Quarkus Flow Structured Logging documentation for detailed configuration options.

Why Epoch Seconds?

Data Index uses FluentBit to collect events, which expects Unix epoch timestamps for TIMESTAMP WITH TIME ZONE columns in PostgreSQL. Using epoch-seconds ensures proper timestamp parsing.

JAX-RS Endpoints (Required)

Quarkus Flow does NOT provide default REST endpoints. You must create JAX-RS resources to trigger workflows:

package com.example.resources;

import com.example.workflows.MyWorkflow;
import io.smallrye.mutiny.Uni;
import jakarta.inject.Inject;
import jakarta.ws.rs.*;
import jakarta.ws.rs.core.MediaType;
import java.util.Map;

@Path("/workflows")
public class WorkflowResource {

    @Inject
    MyWorkflow myWorkflow;

    @POST
    @Path("/start")
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public Uni<Map<String, Object>> startWorkflow(Map<String, Object> input) {
        return myWorkflow.startInstance(input)
                .onItem().transform(result -> result.asMap().orElseThrow());
    }
}

Next Steps

Now that you understand the basics, choose your deployment target:

Local Development with KIND - Test locally
Production Deployment - Deploy to Kubernetes

Both guides cover:

Kubernetes deployment dependencies
Environment-specific property files
Build and deployment commands
Verification steps