Configuration of cloud server and using data in QGIS

[jakubstaszel]

Hello, I am trying to use COPC data in QGIS 3.28.7 from Azure Storage blob, but every time there is an error:
Invalid Data Source: https://magisterkacog.blob.core.windows.net/aois/autzen-classified.copc.laz is not a valid or recognized data source, error: "Unable to recognize https://magisterkacog.blob.core.windows.net/aois/autzen-classified.copc.laz as a LAZ file: "The server of submitted URL doesn't support range queries""

The only thing that I did is that I moved your file from https://s3.amazonaws.com/hobu-lidar/autzen-classified.copc.laz to https://magisterkacog.blob.core.windows.net/aois/autzen-classified.copc.laz. Additionally, the data from S3 is accessible from QGIS, no error.

I configured CORS and the data is normally visible in COPC Viewer, the problem is only with QGIS. Can you tell me what additional configuration you did for S3?

[connormanning]

Your data works fine for me: example.

So you'll have to ask the QGIS folks why QGIS thinks range requests are not supported when actually they are working. There could be a number of reasons. Maybe there is some preliminary check (like an OPTIONS/HEAD request etc.) that is hinting that Range requests might not be supported so QGIS is not actually continuing on to make any of the GET requests.

As far as I can tell, your endpoint seems configured properly - the key pieces are a) proper CORS and b) enabling Range requests (this was recently added as a note in the spec).

Maybe @wonder-sk can chime in.

[uclaros]

QGIS relies on the server's reply Accept-Ranges header in order to load copc files.
It does a preliminary HEAD request with a Range: bytes=0-0 header and checks for the Accept-Ranges header in the reply.
It seems your server does support range requests but does not advertise so in the headers.

[wonder-sk]

As @uclaros says - QGIS currently requires that server sends Accept-Ranges header in the reply.

Looking at the RFC on range requests, this requirement is maybe a bit strict on QGIS side, as the RFC permits clients to do range requests even if this header is not present. In any case, it is a good idea to have Accept-Ranges: bytes header sent by the server.
https://datatracker.ietf.org/doc/html/rfc7233#section-2.3

[jakubstaszel]

Thank you for the advice! I will start the communication with QGIS community.