Starting from WildFly-8.0.0.Alpha3, OSGi support is not part of WildFly any more. As per: Getting Started - JBoss OSGi - Project Documentation Editor
Red Hat JBoss Fuse is the best option for you.
Copying the Announcement from link https://access.redhat.com/products/red-hat-jboss-fuse-service-works
Red Hat JBoss Fuse Service Works and Red Hat JBoss Fuse have been merged into a single product, known as Red Hat JBoss Fuse. With the merger, you now have consistent integration technology that can be deployed on your container of choice, OSGI based Apache Karaf or Java EE based JBoss EAP.
JBoss OSGI (JBOSGI) for WildFly 9 and WildFly 10 are about 1 and 2 weeks aware respectively.
Snapshot release is available and so far passes all tests on WildFly 9: Index of /repositories/snapshots/org/jboss/osgi/wildfly/jbosgi-wildfly-build/2.4.0.Final-SNAPSHOT