Task 'run' not found in root project ''.

[omriShneor]

Im trying to create a dockerfile running this webapp as a service.
and im getting the following:

Unzipping /root/.gradle/wrapper/dists/gradle-2.3-bin/a48v6zq5mdp1uyn9rwlj56945/gradle-2.3-bin.zip to /root/.gradle/wrapper/dists/gradle-2.3-bin/a48v6zq5mdp1uyn9rwlj56945
Set executable permissions for: /root/.gradle/wrapper/dists/gradle-2.3-bin/a48v6zq5mdp1uyn9rwlj56945/gradle-2.3/bin/gradle
Native Lib Architecture: Clifferx64

FAILURE: Build failed with an exception.

• What went wrong:
  Task 'run' not found in root project ''.

• Try:
  Run gradlew tasks to get a list of available tasks. Run with --stacktrace option to get the stack trace. Run with --inf or --debug option to get more log output.

BUILD FAILED

any ideas why?