Allow additional fields in Cloud Storage Connection credentials (or maybe gdal credentials more broadly)

[fvankrieken]

Feature description

When adding an AWS S3 Cloud Storage Connection from the browser, be able to set AWS_S3_ENDPOINT in the credentials widget

Additional context

Very excited to use the s3 browser connection added in #57870. However, my organization uses Digital Ocean Spaces. This implements AWS S3 api, but with a custom endpoint. Connecting to it in python for example with gdal, we do the following

gdal.SetConfigOption("AWS_S3_ENDPOINT", os.environ["AWS_S3_ENDPOINT"])
gdal.SetConfigOption("AWS_SECRET_ACCESS_KEY", os.environ["AWS_SECRET_ACCESS_KEY"])
gdal.SetConfigOption("AWS_ACCESS_KEY_ID", os.environ["AWS_ACCESS_KEY_ID"])

The first field here, AWS_S3_ENDPOINT, is not an option in the widget to add credentials, meaning we're unable to connect to buckets on this custom endpoint using cloud -> AWS S3 in the browser

The only space I see the AWS... variables referenced explicitly in the repo is in https://github.com/qgis/QGIS/blob/master/src/gui/providers/gdal/qgsgdalcredentialoptionswidget.cpp#L610, though that doesn't include all the options shown in my screenshot so I'm not certain that's where it would need to be added.

[agiudiceandrea]

@fvankrieken, thanks for reporting. AFAIK the available options are retrieved from the GDAL library. The missing one should be probably added to https://github.com/OSGeo/gdal/blob/3da654408183e34eed4be7981f1070a3f0c19824/port/cpl_vsil_s3.cpp#L1904-L1941
Ping @rouault.

[rouault]

AFAIK the available options are retrieved from the GDAL library.

indeed, I see a call to

QGIS/src/gui/providers/gdal/qgsgdalcredentialoptionswidget.cpp

Line 551 in 4274ad8

const char *pszVsiOptions( VSIGetFileSystemOptions( vsiPrefix.toLocal8Bit().constData() ) );

The missing one should be probably added to https://github.com/OSGeo/gdal/blob/3da654408183e34eed4be7981f1070a3f0c19824/port/cpl_vsil_s3.cpp#L1904-L1941

yes, pull request welcome