Camel Integration

Introduction

Apache Camel is a powerful, lightweight integration framework that enables developers to seamlessly connect diverse systems and applications using well-established Enterprise Integration Patterns (EIPs). It simplifies complex integration challenges by providing a domain-specific language (DSL) to define routing and mediation rules in a readable, declarative manner.

Camel Integration Support

For Domain Services based on Java Spring Boot Stack 2.0, IBM Industry Solutions Workbench provides various capabilities, to easily integrate with the help of the Opensource integration framework Apache Camel

The extension is available for the following project types:

Enable Extension

Before using Apache Camel, you need to enable the Camel extension in the k5-project.yaml file.

.....
camelIntegrationSupport:
  enabled: true

ℹ️note

The Camel extension will be automatically enabled when the Saga extension is enabled.

POM Dependencies

When camel integration extension is enabled the following dependencies will be added automatically to your project pom.xml file

  <dependencies>
        <dependency>
            <groupId>org.apache.camel</groupId>
            <artifactId>camel-core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.camel.springboot</groupId>
            <artifactId>camel-lra-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.camel.springboot</groupId>
            <artifactId>camel-spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.camel</groupId>
            <artifactId>camel-log</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.camel.springboot</groupId>
            <artifactId>camel-spring-security-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.camel</groupId>
            <artifactId>camel-servlet</artifactId>
        </dependency>
    </dependencies>

Servlet Initialization

If you want to customize any servlet property for your local development edit application-local.yaml

camel:
  servlet:
    mapping:
      enabled: true
      context-path: /camel/*
      servlet-name: customServlet

Deployment

You can customize the same properties for single deployment using API Configuration Management. Use POST /api/cfg/v1/runtimes/{runtimeName}/solutions/{solutionAcronym}/configurations/{configurationName} with body like the following

extraConfiguration:
  camel:
    servlet:
      mapping:
        enabled: true
        context-path: /camel/*
        servlet-name: customServlet

For application composition use Configuring components with Custom configuration like the following

extraConfiguration:
  camel:
    servlet:
      mapping:
        enabled: true
        context-path: /camel/*
        servlet-name: customServlet

Camel Security

If you want to secure your camel routes you can enable camel security. Enable secure camel will make sure that all your camel routes like "servicePath/camel/firstRoute" are protected with authorization token

ℹ️note

Check Servlet Initialization to customize your context path.

If you want to enable security for your local development edit application-local.yaml

feature:
  secure-camel:
    enabled: false

Deployment

You can enable security for single deployment using API Configuration Management. Use POST /api/cfg/v1/runtimes/{runtimeName}/solutions/{solutionAcronym}/configurations/{configurationName}

extraConfiguration:
  feature:
    secure-camel:
      enabled: false

For application composition use Configuring components with Custom configuration like the following

extraConfiguration:
  feature:
    secure-camel:
      enabled: false

Implement Camel Routes

Apache Camel is a powerful integration framework for Java Spring Boot applications, designed to simplify message routing and processing, an implementation stub is generated under "src/main/java/yourProject/camel/camelRoutes.java

Example:

@Component
public class CamelRoutes extends RouteBuilder {
  @Override
  public void configure() throws Exception {
    
    // Using Rest DSL
    rest("/")
      .get("order/{id}?matchOnUriPrefix=true").to("direct:getOrder")
      .post("order/{id}?matchOnUriPrefix=true").to("direct:postOrder");

    // Using Direct rest
    from("rest:post:/postOrderRest?matchOnUriPrefix=true")
      .routeId("postOrderRest")
      .log("REST: Processing new order: ${body}")
      .to("direct:saveOrder");

    // Direct        
    from("direct:saveOrder")
      .routeId("saveOrder")
      .log("Saving new order: ${body}")
      .to("mock:database");
    
    // Direct
    from("direct:getOrder")
      .routeId("getOrder")
      .log("Direct: Getting order: ${header.id}")
      .setBody(simple("Direct: Get Order Details for ID ${header.id}"));

     // Direct
    from("direct:postOrder")
      .routeId("postOrder")
      .log("Direct: Posting order: ${header.id}")
      .setBody(simple("Direct: Post Order Details for ID ${header.id}"));

    // secured servlet
    from("servlet:/secured").process(new Processor() {
      public void process(Exchange exchange) throws Exception {
        // Access HTTP headers sent by the client
        Message message = exchange.getMessage();
        String contentType = message.getHeader(Exchange.CONTENT_TYPE, String.class);
        String httpUri = message.getHeader(Exchange.HTTP_URI, String.class);
        String authHeader = message.getHeader("Authorization", String.class);

        // Set the response body
        message.setBody("<b>Got Token: " + authHeader +  "Content-Type: " + contentType + ", URI: " + httpUri + "</b>");
      }
    });

}

ℹ️note

The Camel integration is only available for Domain Services (Java) based on Java Spring Boot Stack 2.0

Introduction​