url routing - Python flask web application with multilanguages support by host and prefix

Question

I have one server with flask application instance and have several domain which mapped to this server by DNS.

My site must support several languages by host and prefix:

mysite.com - english
mysite.com/fr - franch
mysite.ru - russian
mysite.ru/by - belarusian
localhost or other unknown host without language prefix - default language (english)

I implemented it with double route registration /endpoint and /<lang>/endpoint and reloaded url_for function and it work, but now I must implement custom error pages for abort function:

mysite.com/wrong-url-there - mysite.com/404.html (english)
mysite.com/fr/wrong-url-there - mysite.com/fr/404.html (franch)
mysite.ru/wrong-url-there - mysite.ru/404.html (russian)
mysite.ru/by/wrong-url-there - mysite.ru/by/404.html (belorusian)

And I don't see solution for this. I think my implementation bad and I must improve it. I think I must create one instance of application for each site language root with predefined language for it or use blueprint, but I don't find solution for me yet.

Is anybody can give me advice how resolve this url multilanguages support with flask or wsgi or nginx?

Answer 1

It's in the official doc: http://flask.pocoo.org/docs/patterns/urlprocessors/ (This is basically the same answer as Matthew Scragg's).