Master Component

If you do not already have a fabric, enter the following console command to create one:

JBossFuse:karaf@root> fabric:create --new-user AdminUser --new-user-password AdminPass
  --zookeeper-password ZooPass --wait-for-provisioning

The --new-user and --new-user-password options specify the credentials for a new administrator user. The Zookeeper password is used to protect sensitive data in the Fabric registry service (all of the nodes under /fabric).

Note

If you use a VPN (virtual private network) on your local machine, it is advisable to log off VPN before you create the fabric and to stay logged off while you are using the local container. A local Fabric Server is permanently associated with a fixed IP address or hostname. If VPN is enabled when you create the fabric, the underlying Java runtime is liable to detect and use the VPN hostname instead of your permanent local hostname. This can also be an issue with multi-homed machines. To be absolutely sure about the hostname, you could specify the IP address explicitly—see ????.

For this example, you must have access to a running instance of an Apache ActiveMQ broker and you must know the IP port of the broker's OpenWire connector. For example, you might get access to an ActiveMQ broker in one of the following ways:

Create the master-example profile, which will be used to deploy a simple Apache Camel route that uses the Master component. Enter the following console command to create the profile:

JBossFuse:karaf@root> fabric:profile-create --parents default master-example

Add the requisite Karaf features to the master-example profile. Enter the following console commands:

fabric:profile-edit --features fabric-camel master-example
fabric:profile-edit --features activemq-camel master-example

Define the simple Camel route as a resource in the master-example profile. Invoke the built-in text editor to create a new camel.xml resource, as follows:

fabric:profile-edit --resource camel.xml master-example

Copy and paste the following content into the built-in text editor:

<?xml version="1.0" encoding="UTF-8"?>
<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

    <reference id="curator" interface="org.apache.curator.framework.CuratorFramework"/>

    <camelContext id="camel" xmlns="http://camel.apache.org/schema/blueprint">
        <route id="fabric-server">
            <from uri="master:lockhandle:activemq:queue:FABRIC.DEMO"/>
            <log message="Message received : ${body}"/>
        </route>
    </camelContext>

    <bean id="activemq"
          class="org.apache.activemq.camel.component.ActiveMQComponent">
        <property name="brokerURL" value="tcp://localhost:OpenWirePort"/>
        <property name="userName" value="UserName"/>
        <property name="password" value="Password"/>
    </bean>

</blueprint>

Remember to customize the route configuration by replacing OpenWirePort with the port number of the OpenWire connector on the broker, and by replacing UserName and Password by any valid JAAS credentials on the container (for example, you could substitute the AdminUser and AdminPass credentials created in Step 1 of these instructions).

To save and exit from the text editor, type Ctrl-S, Ctrl-X.

Configure the master-example profile to deploy the camel.xml resource as an OSGi bundle. Enter the following console command to create a new entry in the master-example agent properties:

fabric:profile-edit --bundles blueprint:profile:camel.xml master-example

	Note
	The blueprint: prefix tells Fabric to deploy the specified resource as a Blueprint XML file, and the profile: prefix tells Fabric where to find the resource (that is, in the current version of the current profile).

Create two new child containers, so that you can deploy the master-example profile as a cluster (one master and one slave). Enter the following console command:

fabric:container-create-child root child 2

Now deploy both the master-example profile and the mq-client profile to each of the child containers, as follows:

fabric:container-change-profile child1 master-example mq-client
fabric:container-change-profile child2 master-example mq-client

If you now send some messages to the FABRIC.DEMO queue on the broker, the messages are consumed by one (and only one) of the deployed master endpoints. For example, you can easily create and send messages to the broker using the browser-based Fuse Management console.

If you stop the container that hosts the current master (initially, the child1 container), the slave will be promoted to be the new master (in the child2 container) and will start consuming messages from the FABRIC.DEMO queue. For example, assuming that child2 contains the current master, you can stop it by entering the following console command:

fabric:container-stop child2