I was trying karaf4.x with the DS(declarative service) in command bundles, but found it falied to get service via DS.
karaf.log
2017-07-10T15:01:43,163 | INFO | pipe-bundle:install -s mvn:com.gogo.sdn/opensdn-hello-cli/1.0-SNAPSHOT | CommandExtension | 38 - org.apache.karaf.shell.core - 4.1.1 | Command registration delayed for bundle com.gogo.sdn.opensdn-hello-cli/1.0.0.SNAPSHOT. Missing dependencies: [com.gogo.sdn.core.service.hello.HelloService]
