Docker image $PATH does not include confluent-hub executable

[colinhicks]

Describe the bug With the UBI image introduced in ksqlDB 0.9.0, the confluent-hub executable is installed to /home/appuser/bin. This directory is not on the default $PATH, so invoking confluent-hub via docker run fails.

To Reproduce

docker run -it confluentinc/ksqldb-server:0.9.0 confluent-hub
docker: Error response from daemon: OCI runtime create failed: container_linux.go:346: starting container process caused "exec: \"confluent-hub\": executable file not found in $PATH": unknown.

Additional context

• Previously confluent-hub was installed into /bin:

  docker run -it confluentinc/ksqldb-server:0.8.1 which confluent-hub
  /bin/confluent-hub

• /home/appuser/bin is added to $PATH after user login, by .bashrc. So incantations like docker run -it ... bash -lc confluent-hub work against 0.9.0 (the -l switch runs the shell login procedure).

[colinhicks]

This can be addressed either by:

• Extracting confluent-hub to the root /bin, or
• Updating the Dockerfile to extend the default value of $PATH: ENV PATH /home/appuser/bin:$PATH