URL ‘/hello’ rule in public site

[usingsky]

I suggest providing the /hello path only in debug mode.

CKAN Version if known (or site URL)

2.8

Please describe the expected behaviour

Ckan extension can determine whether to use /hello routing.

Please describe the actual behaviour

Currently ckan core provides the "/hello" path by default.
In a production build, I think this is unnecessary information for users.
There is no way to remove "/hello" routing from an extension without modifying the core, and it must be redefined.

What steps can be taken to reproduce the issue?

It is being routed on some sites based on ckan
eg)
https://demo.ckan.org/hello
https://data.stadt-zuerich.ch/hello
https://data.gov.ie/hello
https://ckan0.cf.opendata.inter.sandbox-toronto.ca/hello

[amercader]

Thanks @usingsky . That's a leftover from the initial stages of the Flask migration. I've removed in #4913