`rabbitmqctl environment` JSON output prints all `string()`s as-is

[the-mikedavis]

Describe the bug

Erlang string()s in application env are printed by rabbitmqctl environment --formatter=json as lists of bytes rather than as JSON strings.

Reproduction steps

1. make run-broker
2. rabbitmqctl environment --formatter=json

Expected behavior

Values like application:get_env(rabbit, cluster_name) should be printed as JSON strings like "cluster_name":"localhost". Currently they are printed as lists of bytes: "cluster_name":[108,111,99,97,108,104,111,115,116]

Additional context

Any binary()s and atom()s are printed as expected, like "anonymous_login_user":"guest".

I'm not sure this can be solved without false-positives but we can try to do as well as EShell and convert lists of UTF-8-looking bytes to binaries.

[michaelklishin]

@the-mikedavis that command was never supposed to support the JSON formatter. I don't think you can realistically map an arbitrary Erlang application environment data structure to JSON because some things do not map well (functions, function references, tuples, atoms).

I'd much rather introduce a new HTTP API endpoint and/or rabbitmq-diagnostics command that would produce just enough data in a JSON-friendly format.

[lukebakken]

Re-opening because the fix turns out to be pretty simple.