[BUG]: Access blocked for OpenStreetMap tiles

[elpamplina]

Description

Generating a map from OpenStreetMap, some tiles are filled with the error message: "403r Access blocked. Referer is required by tile usage policý of OpenStreetMap's volunteer-run servers: osm.wiki/Blocked"

This occurs randomly about half the times, on one or more tiles.

Screenshots/Video

Steps to reproduce

Python code:

import plotly.graph_objects as go

lat = 41.580472
lon = -1.1161953

fig = go.Figure(go.Scattermap(
    lat=[lat],
    lon=[lon],
    mode='markers',
    marker=dict(symbol="circle", size=30)
))
fig.update_layout(
    map=dict(
        style="open-street-map",
        center=dict(lat=lat, lon=lon),
        zoom=16
    ),
    margin={"r": 0, "t": 0, "l": 0, "b": 0} 
)
img = fig.to_image('png')

with open('map.png', 'wb') as f:
    f.write(img)

Generated with:
plotly 6.6.0
kaleido 1.2.0

[StyXman]

According to OSM's tile policy https://operations.osmfoundation.org/policies/tiles/ you have to either set "a valid HTTP User-Agent [header]" or "a valid HTTP Referer header", otherwise you might get throttled as above.

Plotly should allow to provide either of these so OSM people are happy.

[camdecoster]

I just tried running your example and didn't see an issue. Is the problem still happening for you?

[camdecoster]

The image I produced:

[NorthLake]

I just tried running your example and didn't see an issue. Is the problem still happening for you?

For us the issue happens every 50% of times a map is rendered, I'd say. Only some of the tiles in view would be replaced by the error. Perhaps it's a usage thing that regular testing wouldn't bring up?
Either way, I took a look at the obfuscated frontend code, and it seems like the referrer is passed along when creating the Request object, but the browser ignores the argument and sets it to about:client. At least, that's the case for us when rendering it in a new iframe (using Viktor). Why this is the case I do not know, but that's why OpenStreetMap is saying the referer header is missing.