Strategies for using renv in Docker

This repository showcases different ways to handle renv cache in docker.

Case	Description
01-cache-in-project	Renv cache is kept locally in the project, restore happens in docker build
02-cache-in-project-restore-after	Mounts the cache and restores when container is run
03-global-cache-restore-after	Keeps cache outside the project, restores when container is run, as in case 02

Tip

To try them out, clone this repo and do:

• cd 01-cache-in-project
• make shell
• R
• library(tidyverse)

All cases should behave the same, you can run make shell in either. In all of them it should say:

- Project '/project' loaded. [renv 1.1.1]
> library(tidyverse)
── Attaching core tidyverse packages ─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── tidyverse 2.0.0 ──
✔ dplyr     1.1.4     ✔ readr     2.1.5
✔ forcats   1.0.0     ✔ stringr   1.5.1
✔ ggplot2   3.5.1     ✔ tibble    3.2.1
✔ lubridate 1.9.4     ✔ tidyr     1.3.1
✔ purrr     1.0.4
── Conflicts ───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── tidyverse_conflicts() ──
✖ dplyr::filter() masks stats::filter()
✖ dplyr::lag()    masks stats::lag()
ℹ Use the conflicted package (<http://conflicted.r-lib.org/>) to force all conflicts to become errors

Case 01: Cache in project

This setup keeps the renv cache in the project (in this example in a subfolder .renv_cache/.

This renv cache is ignored by git, but not by docker.

During build, the cache is copied into the image to make it available for subsequent renv::restore()

When running, the cache is mounted as a volume in the container so that cache from future renv installs are persistently captured in the cache.

Case 02: Cache in project, but restore at runtime

This setup is similar to Case 01 in that it maintains the renv cache in the project, but renv::restore() is not called during build. Cache is also not copied into the image during build.

Case 03: Cache outside, shared between projects, and restored at runtime

For all intents and purposes an identical setup to Case 02, with the only difference that cache is kept outside of the project and potentially shared with other projects.