Context: I manage a shinyproxy server and we use golem for most of our apps. They deploy via an AWS CD pipeline powered by a Dockerfile created with golem::add_dockerfile()

Problem: docker build can fail when installing packages from github because the rate limit of the GitHub API is exceeded.

For example, this is from my AWS build log:

1090 | Error: Failed to install 'unknown package' from GitHub:
1091 | Failed to install 'gargle' from GitHub:
1092 | HTTP error 403.
1093 | API rate limit exceeded for 35.176.92.34. (But here's the good news: Authenticated requests get a higher rate limit. Check out the documentation for more details.)
1094 |  
1095 | Rate limit remaining: 0/60
1096 | Rate limit reset at: 2020-10-12 16:31:43 UTC
1097 |  
1098 | To increase your GitHub API rate limit
1099 | - Use `usethis::browse_github_pat()` to create a Personal Access Token.
1100 | - Use `usethis::edit_r_environ()` and add the token as `GITHUB_PAT`.
1101 | Execution halted
1102 | The command '/bin/sh -c Rscript -e 'remotes::install_github("tidyverse/googlesheets4@b86b6f76ee857493dd58135169272c66cb5493f2")'' returned a non-zero code: 1
1103

Solution: Change the command used to install packages from github in the Dockerfile:

RUN Rscript -e 'remotes::install_github("r-lib/[email protected]")'

should become

ARG GITHUB_PAT  # Only once before non CRAN remotes
RUN GITHUB_PAT=$GITHUB_PAT Rscript -e 'remotes::install_github("r-lib/[email protected]")'

This would allow the user to pass a GITHUB_PAT when building the docker image and avoid the rate limit. Another HUGE advantage is that it would allow access to private repository!

I would suggest adding a logical argument use_github_pat = FALSE to the various add_dockerfile_XXX() functions. The default value (FALSE) would preserve the existing behaviour but use_github_pat = TRUE would add the necessary code in the Dockerfile.

Note that the user does not need to pass the value of their GITHUB_PAT to add_dockerfile. Instead it must be passed as a build argument when calling docker build.

Migrated from ThinkR-open/golem#531