Design a REST Microserviceusing Apache Cameltechnology

Charles Moulliard (@cmoulliard)22 Jan 2016

Who

Committer, Coder, Architect

Work on Apache Camel, Karaf, Fabric8, Hawtio, Apiman, DeltaSpike

Mountain Biker, Belgian Beer Fan

Blog:

Twitter:

Email:

http://cmoulliard.github.io

@cmoulliard

cmoulliard@redhat.com

Agenda

Integration …

Apache Camel

Micro Container

Kubernetes Service

 

Integration

Point to Point vision

Integrate many systems. Play with formats & protocols

Hub Approach

In 2003, it was reported that 70% of all EAI projects fail !

Bus

Communication done through a Bus with Normalized messages

MicroService

It is an architectural style wherean application

composed of individualstandalone services

communicating usinglightweight protocols

in event based manner

 

Apache Camel

Apache Camel

Java Integration Framework

Implements Domain Specific Language

Supports Enterprise Integration Patterns

Enterprise Patterns

implemented

and more : Loadbalancer, Throttler, Delayer, …

> 50 patterns

Route, processor

Camel project Collection of routes

Route = Processor(s) + Interceptor(s)

Producing or consuming Message

Java DSL

Fluent API, extend RouteBuilder class

import org.apache.camel.builder.RouterBuilder;

public class FilterRoute extends RouteBuilder {

public void configure() throws Exception {

from("activemq:queue:all") .filter(xpath("/quote/product = 'widget'")) .to("activemq:widget"); } }

XML DSL

Spring, Blueprint

<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd ">

<bean id="quotesService" class="my.cool.demo.camel.QuotesService"/>"

<camelContext xmlns="http://camel.apache.org/schema/spring"> <route> <from uri="activemq:queue:all"/> <filter> <xpath>"/quote/product/ = 'widget"</xpath> <bean id="quotesService" method="widget"/> </filter> </route> </camelContext>

REST DSL

One of the components available : servlet, jetty, netty, spark, restlet,undertow

Hostname

Port

Root of the REST Application endpoint

@Override public void configure() throws Exception {

restConfiguration() .component("servlet") .host(HOST) .setPort(PORT);

// use the rest DSL to define the rest services rest("/users/") .get("{id}/hello") .route() .process(new Processor() { public void process(Exchange exchange) throws Exception { String id = exchange.getIn().getHeader("id", String.class); exchange.getOut().setBody("Hello " + id + "! Welcome from pod : " } });

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Container agnostic

Endpoints registered CamelContext

Policy

Security

Lifecycle

Tracing

JMX

Threads can be configured

 

Demo

 

Docker Container

Process

Docker

Union FS mounted with immutable images

Benefits: portability, reusability, versioning, application-centric

Docker config

Docker

Container runtime, Process launcher

Maven Docker Plugin

docker:build Build image of app

docker:push Push image

<docker.from>fabric8/s2i-java:1.2</docker.from> <docker.image>${docker.registryPrefix}fabric8/${project.artifactId}:${project.version}<docker.port.container.jolokia>8778</docker.port.container.jolokia> <docker.registryPrefix>${env.DOCKER_REGISTRY}/</docker.registryPrefix>

<plugin> <groupId>org.jolokia</groupId> <artifactId>docker-maven-plugin</artifactId> <version>${docker.maven.plugin.version}</version> <configuration> <images> <image> <name>${docker.image}</name> <build> <from>${docker.from}</from> <assembly> <basedir>/deployments</basedir> <descriptorRef>hawt-app</descriptorRef> </assembly> <env> <JAVA_LIB_DIR>/deployments/lib</JAVA_LIB_DIR> <JAVA_MAIN_CLASS>org.apache.camel.cdi.Main</JAVA_MAIN_CLASS> </env>

 

With Docker

 

 

Kubernetes & Openshift

Kubernetes

Runtime & Operational management of containers

ApiServer (event, status)

Scheduler, Controller & State Storage

Agent - Kubelet - manage containers on host

Containers pods (= shared docker containers)

Kubernetes

Pod & docker

Communicate to each other using skyDNS to resolve hostname

Pod & port

Ports can be exposed

Pod & volume

Share data using mounted volume between host & container

Kubernetes Service

Kube Service loadbalanced through the pods using HA-Proxy Routes mapprivate with public IP address

Kube Application JSon

 

Fabric8

Fabric8 Maven Plugin

fabric8:json generates Kube MetaData

fabric8:apply deploy on Openshift

<fabric8.service.name>hellorest</fabric8.service.name> <fabric8.service.port>9090</fabric8.service.port> <fabric8.service.containerPort>8080</fabric8.service.containerPort>

<fabric8.label.component>${project.artifactId}</fabric8.label.component> <fabric8.label.container>tomcat</fabric8.label.container> <fabric8.label.group>demo</fabric8.label.group> <fabric8.service.type>LoadBalancer</fabric8.service.type> <fabric8.iconRef>camel</fabric8.iconRef>

<plugin> <groupId>io.fabric8</groupId> <artifactId>fabric8-maven-plugin</artifactId> <version>${fabric8.version}</version> <executions> <execution> <id>json</id> <goals> <goal>json</goal> </goals>

 

With OpenShift & Kubernetes

 

Questions

Twitter :

Camel Rest MicroService in Action

@cmoulliard

https://github.com/FuseByExample/microservice-camel-in-action

http://fabric8.io/