Configuring port offset on JBoss AS / WildFly

Do you want to learn how to change the default ports in WildFly application server? Then keep reading this tutorial!

Port offset is an useful tweak which can be applied to execute several application servers on the same machine. A typical usage of the port-offset is for creating a vertical cluster, with multiple nodes on the same machine.

In standalone mode, the port offset is contained in the standard-sockets definition:

<socket-binding-group name="standard-sockets" default-interface="public"  
 port-offset="${jboss.socket.binding.port-offset:0}">

        <socket-binding name="management-http" interface="management" port="${jboss.management.http.port:9990}"/>
        <socket-binding name="management-https" interface="management" port="${jboss.management.https.port:9993}"/>
        <socket-binding name="ajp" port="${jboss.ajp.port:8009}"/>
        <socket-binding name="http" port="${jboss.http.port:8080}"/>
        <socket-binding name="https" port="${jboss.https.port:8443}"/>
        <socket-binding name="txn-recovery-environment" port="4712"/>
        <socket-binding name="txn-status-manager" port="4713"/>
        <outbound-socket-binding name="mail-smtp">

            <remote-destination host="localhost" port="25"/>

        </outbound-socket-binding>

</socket-binding-group>

As you can see it contains a Beanshell expression which means, unless the jboss.socket.binding.port-offset is set, it evaluates to 0 so to standard sockets.

So by starting the standalone server with:

standalone.sh -Djboss.socket.binding.port-offset=100

 …will shift all ports by 100. This means also the management bindings, such as management-http and management-https :

13:36:47,186 INFO  [org.jboss.as] (Controller Boot Thread) WFLYSRV0060: Http management interface listening on http://127.0.0.1:10090/management
13:36:47,187 INFO  [org.jboss.as] (Controller Boot Thread) WFLYSRV0051: Admin console listening on http://127.0.0.1:10090
13:36:47,187 INFO  [org.jboss.as] (Controller Boot Thread) WFLYSRV0025: WildFly Full 14.0.0.Final (WildFly Core 6.0.1.Final) started in 20057ms - Started 1057 of 1226 services (359 services are lazy, passive or on-demand) 

If you want to apply the change permanentely in your configuration, then you can achieve the same result with:

/socket-binding-group=standard-sockets:write-attribute(name=port-offset,value=100)

Assigning a Fixed port to WildFly

Another thing that not every administrator knows, is that you can assign a fixed port value to a binding. This is usually the case of the HTTP port which is often decided with different rules other than port offset. You can set a fixed port bindings by CLI as follows:

/socket-binding-group=standard-sockets/socket-binding=http:write-attribute(name=fixed-port,value=true)

This results in the following:

<socket-binding name="http" port="${jboss.http.port:8080}" fixed-port="true"/>

Binding a single interface to an IP Address

Finally, one tricky question could be, how do you bind just one channel (let’s say http) to an IP address, while keeping the others on the default interface (loopback) ? That’s not too complex to do: you have to define one interface at first with your binding rule: 

<interfaces>

  . . . .

	<interface name="allIPs">

            <inet-address value="${jboss.bind.address:0.0.0.0}"/>

        </interface>

</interfaces>

Now you can use the interface attribute on the single socket binding:

/socket-binding-group=standard-sockets/socket-binding=http:write-attribute(name=interface,value=allIPs)

This way, you can mix and match the inet address used by the single channels.

Domain mode

When running in Domain mode, you cannot use the property -Djboss.socket.binding.port-offset at start up to shift the port of your Domain Servers.

You must apply the port offset change through the Host Controller that govern the server:

/host=master/server-config=server-one:write-attribute(name=socket-binding-port-offset,value=100)

 This results in the following change in the host.xml configuration file:

<server name="server-one" group="main-server-group" auto-start="true">
            <socket-bindings port-offset="100"/>
</server>