Currently the portable Flink runner only works with SDK Docker containers for execution (DockerJobBundleFactory, besides an in-process (embedded) factory option for testing ). I'm considering adding another out of process JobBundleFactory implementation that directly forks the processes on the task manager host, eliminating the need for Docker. This would work reasonably well in environments where the dependencies (in this case Python) can easily be tied into the host deployment (also within an application specific Kubernetes pod).
There was already some discussion about alternative JobBundleFactory implementation in . There is also a JIRA to make the bundle factory pluggable , pending availability of runner level options.
For a "ProcessBundleFactory", in addition to the Python dependencies the environment would also need to have the Go boot executable  (or a substitute thereof) to perform the harness initialization.
Is anyone else interested in this SDK execution option or has already investigated an alternative implementation?