In smaakage85/dockr: Creation of Lightweight Docker Images for Your Packages

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  fig.path = "man/figures/README-"
)

options(repos = c(CRAN = "https://cran.rstudio.com/"))

dockr

dockr is a small toolkit to build a lightweight Docker r-base container image for your R package, in which the package itself is available. The Docker image seeks to mirror your R session as close as possible with respect to R specific dependencies. Both dependencies on CRAN R packages as well as local non-CRAN R packages will be included in the Docker container image.

Installation

Install the development version of dockr with:

remotes::install_github("smaakage85/dockr")

Or install the version released on CRAN:

install.packages("dockr")

Workflow

In order to create the files, that will constitute the Docker image, simply invoke the prepare_docker_image() function and point to the folder with your package.

The workflow of prepare_docker_image() is summarized below:

Build and install the package on your system
Identify R package dependencies of the package
Detect the version numbers of the loaded and installed versions of these packages on your system
Link the individual packages to the right repositories (either CRAN or local repos)
Write Dockerfile and create all other files needed to build the Docker r-base image

Now, I will let dockr do its magic and create the files for a Docker r-base container image, in which dockr is installed together with all of the R package dependencies, dockr needs to run.

Beware that the files for the Docker image are created as side-effects of the function call (under the 'dir_image' directory). Also the package is installed as a side effect (in the 'dir_install' directory).

library(dockr)
image_dockr <- prepare_docker_image(".", dir_image = tempdir(), 
                                    dir_install = "temp")

Great, all necessary files for the Docker image have been created, and you can build the Docker image right away by following the instructions. It is as easy as that! Yeah!

What about non-R dependencies?

dockr does not deal with non-R dependencies at this point. In case that, for instance, your package has any Linux specific dependencies, you will have to install them yourself in the Docker container image. For that purpose you can edit the Dockerfile further with the 'write_lines_to_file' function.