Flask: Define reloader extra_files in `flask run` CLI

[rochacbruno]

Expected Behavior

I expected to have FLASK_RUN_EXTRA_FILES to be processed in the same way of FLASK_RUN_PORT and FLASK_RUN_HOST

When using the old style app.run we can define an extra_files to be watched for changes by the reloader, that is useful for example, if you have a static settings file like settings.toml (using dynaconf) or another kind of static config or themed templates loaded from other paths

Actual Behavior

In the run command https://github.com/pallets/flask/blob/master/flask/cli.py#L775 the argument extra_files is not being passed to wekzeug.run_simple https://github.com/pallets/werkzeug/blob/master/werkzeug/serving.py#L738

Suggestion

Add FLASK_RUN_EXTRA_FILES="path1,path2,path" to flask run command.

or

Map all variables from werkzeug.run_simple - https://github.com/pallets/werkzeug/blob/master/werkzeug/serving.py#L738

In to FLASK_RUN_* prefixed env var or WERKZEUG_RUN_* prefixed env var.

Environment

• Python version: 3.6
• Flask version: 1.0.2
• Werkzeug version: 0.14.1

[rochacbruno]

I can provide a Pull Request to add this, just let me know what you think about it.

[RonnyPfannschmidt]

i believe adding a argument/cli option for the extra files should fit the expectations well
i'd like @davidism 's input on this as well

[davidism]

I'm fine with adding it.