Custom Docker Image Support for other R version

[colbyford]

In an effort to use an R package that requires R 4.0 in Azure Machine Learning, I have attempted to create a custom Docker image that installs R 4.0 using conda install -c conda-forge -y r-base=4.1.0 rpy2, which causes issues given the current Python version (and other packages) on the base image.

Are the Dockerfiles for the azureml MCR base images available on GitHub anywhere? If not, do you have recommendations for upgrading R to a desired version on an existing base image.

Notes:

• I am using base image: mcr.microsoft.com/azureml/base:openmpi3.1.2-ubuntu18.04
• I have attempted to create a new conda environment with Python 3.9 and R 4.1.0, but was unable to get Azure ML to use the new environment.

[csetzkorn]

I have the suspicion that R 4.0 is not supported at all (like for SQL Server ML server etc.). Might be worth waiting until end of this year if possible.