As Play!Framework has not published the version 2.9, the lack of exported modules makes the run fail.
You should run the app using the following VM parameter :
--add-exports java.base/sun.net.www.protocol.file=ALL-UNNAMED
For example, this can be achieved in Intellij by setting this option to the sbt-shell launch command. Go to Preferences, Build, Execution, Deployment, Build Tools, sbt and add it to the VM parameters.
When building the Docker image, this parameter can be passed to the JVM, using the -J option :
/app/bin/briventory -Dconfig.file=$CONF_FILE -Dpidfile.path=/var/run/briventory.pid -Djava.awt.headless=true -J--add-exports -Jjava.base/sun.net.www.protocol.file=ALL-UNNAMED
⚠️ -Jshould be specified after each whitespace.