ShinyApps duplicate environment for local development

Hi: I spent a bunch of time setting up a Shiny app to run on ShinyApps-io only to find that it doesn't work because ShinyApps-io does not support Conda (stated in the 2018 post, /t/how-to-use-conda-environment-in-shinyapps-io/18630). I feel that I would have discovered this more quickly if I could mimic the ShinyApps-io environment locally. My question is, How can I duplicate the ShinyApps-io environment locally, so I can verify that my app' works in the ShinyApps-io environment before deploying? For example, is there a Docker container that mirrors the ShinyApps-io environment?

Thank you.