Brand new rabbitmqctl in 3.7.0

As of v3.7.0 Milestone 8, RabbitMQ ships with a brand new set of CLI tools (rabbitmqctl, rabbitmq-plugins, and more), reworked from the ground-up. We had a few goals with this project.

We wanted to use a more user-friendly command line parser and produce more useful help and error messages.

• CLI tools should be extensible from plugins: plugins such as management, federation, shovel, trust store all have functions that are meant to be invoked by CLI tools but the only way of doing it was rabbitmqctl eval, which is error prone and can be dangerous.
• We wanted to give Elixir a try on a real project and make it easier for developers new to Erlang to extend the CLI functionality.
• Our CLI tools historically didn't have good test coverage; the new ones should (and do).
• CLI tools should be able to produce machine-friendly formats, be it JSON, CSV or something else; there was no internal infrastructure for doing that in the original implementation.
• CLI tools should be a separate repository just like all plugins, client libraries, and so on.

Nine months later the experiment was declared a success and integrated into RabbitMQ distribution.

Please give v3.7.0 Milestone 8 a try and take a look at how easy it is to extend the CLI.

There's also a longer document that covers new features and implementation decisions.