It seems that the GeoServer RAT extension is capable of reading the raster attribute table from the PAM (Persistent Auxiliary metadata) (.aux.xml) sidecar file only when the GeoTiff (and sidecar) file are stored on the local file system. I cannot get it to work for cloud-optmized geotiffs that are stored on s3 (minio). If tried reading with both the s3-geotiff and cog plugins… Is it correct that this functionality has not yet been implemented? Is there a workaround?
The RAT extension is usefull because it includes attribute information in WMS GetFeatureInfo requests and because style info can be generated from it.