Sven's comment above sums up why I migrated it. You're using a development tool, which is used much more frequently by SO folks than SF folks. So not only is your question off-topic *here*, but it stands a better chance of being answered *there*. So in that regard, you're in a better situation now than if your question was left here.

If you'd been asking about general docker engine use, from the command-line, on a Linux server, the question would be on-topic here.