chapter3.md

Create AMQP clients

Our Federated AMQ Interconnect deployment has been completed, and you've visually validated all the expected Router nodes are connected. All there's left to do is to inject a data flow in the routing layer and see how messages cross from one region to another.

The chapter below will help you to build an AMQP producer using Fuse that connects to Region-2 and starts sending AMQP messages. On Region-1 you will connect an AMQP consumer to receive the messages, also built with Fuse.

Above you see how the AMQP producer is connected to Region-2, from where messages will be sent, and an AMQP consumer, connected in Region-1, collecting the messages.

Create a Fuse client producer

We will use Fuse to create an AMQP producer to send messages over the Interconnect layer. The producer will connect to Cluster-2 to send messages.

Create a Fuse project skeleton using the following Maven command:

mvn org.apache.maven.plugins:maven-archetype-plugin:2.4:generate \
-DarchetypeCatalog=https://maven.repository.redhat.com/ga/io/fabric8/archetypes/archetypes-catalog/2.2.0.fuse-740017-redhat-00003/archetypes-catalog-2.2.0.fuse-740017-redhat-00003-archetype-catalog.xml \
-DarchetypeGroupId=org.jboss.fuse.fis.archetypes \
-DarchetypeArtifactId=spring-boot-camel-xml-archetype \
-DarchetypeVersion=2.2.0.fuse-740017-redhat-00003

With coordinates:

'groupId': org.demo
'artifactId': producer
'version': 1.0.0

Add in the POM file the following dependency:

<dependency>
	<groupId>org.apache.camel</groupId>
	<artifactId>camel-amqp</artifactId>
</dependency>	

Add Configuration:

• Point the configuration of this producer to Cluster-2.

  For instance, a sample application.properties should look similar to the configuration below, where the URL points to Cluster-2 running in CRC:

   # AMQP connectivity
   amqp.uri=amqps://cluster2-router-mesh-5671-amq-cluster2.apps-crc.testing:443?transport.trustAll=true&jms.sendTimeout=10000&amqp.saslMechanisms=PLAIN
   amqp.username=guest@cluster2-router-mesh
   amqp.password=sGZqNMFk

  Note: the authentication mechanism is SASL Plain, via TLS. The user/password in this configuration would be the same defaults used to access Interconnect's console.

  Reminders:

  • you can obtain the URL to AMQP's port in Cluster-2 running:

    oc get route cluster2-router-mesh-5671 -o=jsonpath={.spec.host}
    

  • you can obtain the guest's password as follows:

    linux:

    oc get secret cluster2-router-mesh-users -o=jsonpath={.data.guest} | base64 -d
    

    macos:

    oc get secret cluster2-router-mesh-users -o=jsonpath={.data.guest} | base64 -D
    

Add Connection and Routes

• Spring XML:

  	<!-- AMQP connectivity -->
  	<bean id="jmsConnectionFactory"
  		class="org.apache.qpid.jms.JmsConnectionFactory"
  		primary="true">
  			<property name="remoteURI" value="${amqp.uri}" />
  			<property name="username" value="${amqp.username}" />
  			<property name="password" value="${amqp.password}" />
  	</bean>
  	<bean id="jmsCachingConnectionFactory"
  		class="org.springframework.jms.connection.CachingConnectionFactory">
  			<property name="targetConnectionFactory" ref="jmsConnectionFactory" />
  	</bean>
  	<bean id="jmsConfig"
  		class="org.apache.camel.component.jms.JmsConfiguration" >
  			<constructor-arg ref="jmsCachingConnectionFactory" /> 
  			<property name="cacheLevelName" value="CACHE_CONSUMER" />
  	</bean>    
  	<bean id="amqp"
  		class="org.apache.camel.component.amqp.AMQPComponent">
  			<property name="configuration" ref="jmsConfig" />
  	</bean>

• Camel Routes:

  Delete the default Camel route definitions and include the following:

  	<route id="amqp-producer">
  		<from uri="timer:tick"/>
  		<log message="sending AMQP request."/>
  		<setBody>
  			<simple>TLS AMQP message</simple>
  		</setBody>
  		<to uri="amqp:queue:test.tls?concurrentConsumers=10&amp;disableReplyTo=true"/>
  	</route>

Run Fuse locally with:

mvn

You should see in the logs how Camel connects to the cluster and attempts to send a message. In the logs you should see:

... INFO  amqp-producer - sending AMQP request.

You will observe Fuse waits for the process to send the message, but nothing happens. This is because Fuse succeeds to connect but it's not obtaining credit from Interconnect to allow it to send the message. Only when a consumer is on the other end, the producer will obtain credit.

Create a Fuse client consumer

We also use Fuse to create the AMQP consumer that will be listening from Cluster-1.

The Fuse consumer implementation will be identical to the producer, except its configuration will point to Cluster-1, and the Camel route definition will consume from the target address where messages are published.

Use the following Maven coordinates:

'groupId': org.demo
'artifactId': consumer
'version': 1.0.0

A sample application.properties should look similar to the configuration below, where the URL points to Cluster-1 running in CRC:

# Disable HTTP port (prevents conflict with client)
spring.main.web-environment=false

# AMQP configuration to Cluster-1
amqp.uri=amqps://cluster1-router-mesh-5671-amq-cluster1.apps-crc.testing:443?transport.trustAll=true&amqp.saslMechanisms=PLAIN
amqp.username=guest@cluster1-router-mesh
amqp.password=VMBojiuX

Note: the authentication mechanism is SASL Plain, via TLS. The password can be obtained running the following command against Cluster-1

Reminders:

• you can obtain the URL to AMQP's port in Cluster-1 running:

  oc get route cluster1-router-mesh-5671 -o=jsonpath={.spec.host} -n amq-cluster1
  

• you can obtain the guest's password as follows:

  linux:

    oc get secret cluster1-router-mesh-users -o=jsonpath={.data.guest} -n amq-cluster1 | base64 -d
  

  macos:

    oc get secret cluster1-router-mesh-users -o=jsonpath={.data.guest} -n amq-cluster1 | base64 -D
  

The Camel route definition to include can look like:

	<route id="amqp-consumer">
		<from uri="amqp:queue:test.tls"/>
		<log message="GOT AMQP request."/>
	</route>

Run Fuse locally with:

mvn

You should see in the logs how Camel connects to the cluster and starts listening for incoming messages. In the logs you should see:

... Route: amqp-consumer started and consuming from: amqp://queue:test.tls.

If the client is up and running, the flow of messages will begin, since the consumer gives credit to the producer to start sending messages.

Logs from both AMQP clients should be similar to:

• Producer:

   ... INFO  amqp-producer - sending AMQP request.
   ... INFO  amqp-producer - sending AMQP request.
   ... INFO  amqp-producer - sending AMQP request.
   ... 
  

• Consumer:

  ... INFO  amqp-consumer - GOT AMQP request.
  ... INFO  amqp-consumer - GOT AMQP request.
  ... INFO  amqp-consumer - GOT AMQP request.
  ...
  

Interconnect's web console should show on its topology graph all the entities involved:

• routing nodes
• connected web console
• connected producer
• connected consumer

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