Geotiff Tags not fully compatible with GDAL

[jdries]

Describe the bug

It seems not possible to write a band name to geotiff metadata that is compatible with GDAL.
Geotrellis writes this:

<GDALMetadata>
  <Item name="DESCRIPTION" sample="0">B02</Item>
</GDALMetadata>

While GDAL would like to also see a "role" attribute:

<GDALMetadata>
  <Item name="DESCRIPTION" sample="0" role="description">B02</Item>
</GDALMetadata>

In the Geotrellis code, it is very clear that the role attribute is not used:

geotrellis/raster/src/main/scala/geotrellis/raster/io/geotiff/Tags.scala

Line 52 in fa88aed

<Item name={key} sample={i.toString}>{value}</Item>

Originally reported here:
Open-EO/openeo-geopyspark-driver#257

To Reproduce

Simply write a geotiff with tags, trying to set a DESCRIPTION on the bands.

Expected behavior

Geotrellis can generate metadata compliant with GDAL, as it already tries to do that.

Environment

Geotrellis 3.6.x

[pomadchin]

Hey @jdries thanks for reporting, definitely sounds like a bug / oversight to me.