Use rocker/rstudio:3.5.3 as base image

Dockerfile

@@ -1,14 +1,15 @@
 # Only run this after making packrat/packrat.lock by
 # running install_packages.R
 
-FROM rocker/tidyverse:3.5.3
+FROM rocker/rstudio:3.5.3
 
 RUN apt-get update
 
 COPY ./packrat/packrat.lock packrat/
 
+RUN install2.r packrat
+
 RUN Rscript -e 'packrat::restore()'
 
-# .Rprofile doesn't get parsed by Rstudio, so modify Rprofile.site instead
-# This is needed so R uses packrat libraries by default
+# Modify Rprofile.site so R loads packrat library by default
 RUN echo '.libPaths("/packrat/lib/x86_64-pc-linux-gnu/3.5.3")' >> /usr/local/lib/R/etc/Rprofile.site

README.md

@@ -1,6 +1,7 @@
 ## Installing R packages to a Docker image with packrat
 
-This is a minimal example that installs a single package each from CRAN, bioconductor, and github to a Docker image using packrat.
+This is a minimal example that installs a single package each from CRAN,
+bioconductor, and github to a Docker image using packrat.
 
 ### Setup
 
@@ -9,20 +10,19 @@ project directory.
 
 ### First step: make packrat/packrat.lock file
 
-Launch `rocker/tidyverse` with tag set to same version we will use in
-the `Dockerfile`, and this directory mounted.
+Launch `rocker/rstudio` (or any other [rocker image](https://www.rocker-project.org/)
+of your choice) with tag set to same version we will use in the `Dockerfile`,
+and this directory mounted.
 
-Here I'm using `rocker/tidyverse` because it comes with RStudio server, so we can
-edit code in the container directly with RStudio. However, `rocker/tidyverse`
-comes with `tidyverse` pre-installed, so if you want to track those packages
-properly you would have to install them like the other example packages in 
-`install_packages.R`.
+Note that the rocker images come with various packages pre-installed,
+so if you want to track those packages properly you would have to install them
+like the other example packages in `install_packages.R`.
 
 ````
-docker run -it -e PASSWORD=cleverpw -v /path/to/project/:/home/rstudio/project rocker/tidyverse:3.5.3 bash
+docker run -it -e DISABLE_AUTH=true -v /path/to/project/:/home/rstudio/project rocker/rstudio:3.5.3 bash
 ````
 
-Inside the docker container, run the script to install R packages 
+Inside the docker container, run the script to install R packages
 with `packrat`. Exit when done.
 
 ```
@@ -35,7 +35,7 @@ but the main reason is to write `packrat/packrat.lock`.
 
 ### Second step: actually build the image
 
-Now we can use `packrat.lock` to restore (i.e., install) packages when we 
+Now we can use `packrat.lock` to restore (i.e., install) packages when we
 build the image.
 
 ```

install_packages.R

@@ -2,11 +2,10 @@
 
 ### Initialize packrat ###
 
-# rocker/tidyverse comes with packrat, so we don't need to install it.
-# Uncomment the next line if using an image that doesn't already have packrat.
-# install.packages("packrat", repos = "https://cran.rstudio.com/")
+# Install packrat
+install.packages("packrat", repos = "https://cran.rstudio.com/")
 
-# Don't let packrat try to find packages to install itself.
+# Initialize packrat, but don't let it try to find packages to install itself.
 packrat::init(
   infer.dependencies = FALSE,
   enter = TRUE,