OpenStreetMap is blocking use of their tile servers whenever Referrer is not included

[petervanwylen]

Describe the bug
OpenStreetMap is blocking use of their tile servers whenever Referrer is not included. This is a change in the last few days. See https://wiki.openstreetmap.org/wiki/Blocked_tiles.

To Reproduce

Use folium.Map in any way with the default OSM tiles as the map.

Remaining to be understood
Can you send a Referrer header when running in an embedded way say in a Jupyter Notebook? How could their policy be satisfied when it's running locally or just being viewed in a notebook / potentially even a VS Code Notebook that doesn't have a URL (not Jupyter in a browser but Jupyter in an app).

[hansthen]

Hi Peter,

I was unable to reproduce the issue. Do you also have this issue when you open our documentation? https://python-visualization.github.io/folium/latest/index.html should contain some maps that use the OpenStreetMap base tiles.

[petervanwylen]

Hi Hans,

It's only happening for me in two situations. Also this only started a few days ago when they implemented the policy change at OSM.

Situation 1:

m = folium.Map(location=[lat,lng], zoom_start=11)
m.save("smoothed_overlay.html")

Then open up the html file in a browser such that the browser is reading the local filesystem directly / no hosting / not localhost in the location bar. In this case most all browsers will not send referrer information.

Situation 2:
If I create a map in VS Code's notebook app and then run display(m) it will also not have any referrer information. I think it might work in Jupyter Notebook (although I don't ever use that) because Jupyter runs in the browser and may will then send a localhost-like referrer.

-Peter

[hansthen]

Ah I see. That's annoying. We cannot add these headers from Folium, they are added by the browser (or any other html renderer). The best advice I can give for now is to use a different tile provider. Maybe you can host your own?