Adding report generation dependencies to Dockerfile

[dgkf]

First, I didn't have the good sense to look at ongoing work before kicking this off, so some of it is a bit overlapping with @epijim's add/generator branch.

Changes

• Added docker.io/ prefix to FROM statement (thanks podman for warning me that omitting this is a potential security concern... also means the same file should work without issue now on podman as well as docker without additional configurations)
• Added remotes::install_github steps to the Dockerfile to install covtracer from github
• Incorporated params$pkg_dir when collecting git info in the template report
• Generalized the report format to accept any valid render target for rmarkdown::render - defaults to "all" (which uses the output defined in the template, "md_document"). Instead of accepting an extension, this should now accept render formats - eg "pdf_document" instead of "pdf".
• Renamed inputs to have a report_ prefix. Not sure how inputs get managed across multiple actions, but I felt that having a prefix might help mitigate potential input name conflicts. Feel free to revert this change if that's not necessary.

Considerations

I'm not totally comfortable with what directory structure we should assume gets mounted into the action container. I tested it assuming the repo contents get copied into the container's $HOME (/root). Nothing is hard coded around this assumption, but it hasn't been tested against anything else.

[dgkf]

Sorry for the commit spam :stuck_out_tongue:

Looks like remaining issues are in covtracer's ballpark. I'll have to dig into what error it's causing on that end. Otherwise I think this is working as intended.

[dgkf]

This sent me down the rabbit hole. This error can be managed in covtracer, but the root cause actually lies in a difference of behavior in rocker/verse images and its R setup.

I haven't traced it down entirely yet, but for whatever reason the tests aren't being sourced with preserved srcref information when covr runs in a rocker/verse image. This is different from the behavior on all of my local machines and rocker/tidyverse - even on the same R version and package versions. There must be R compile flag, environment variable or option that is configured somewhere changing this behavior.

Still trying to track it down to be more comprehensive in the template, but for the time being I'm going to try to add a safe fallback for this scenario to covtracer.