Dockerize a ShinyApp

In this post I want to describe how to dockerize a simple Shiny App. Docker is a great way of sharing and deploying projects. You can download it here.

Resources:

• R Docker tutorial, recommended for Docker beginners.
• Running a shiny app in a docker container by Mark Sellors (which is an updated and more complete version of this post).

Assume you have a project folder structure as follows:

.
+-- project.Rproj
+-- app.R
+-- R
|   +-- script_1.R
|   +-- script_2.R
+-- data
|   +-- data_df.rds
|   +-- raw_data.csv

• The script app.R contains the code of the Shiny application.
• The folder R contains auxiliary scripts.
• The folder data contains a csv and an rds file which might be nessesary for the application (cleaned data set, for example).

To create a docker image you need to create a Dockerfile, which is a simple text file located in the same directory as app.R. The name of the file must be Dockerfile. A common structure of this file is the following:

# get shiny serves plus tidyverse packages image
FROM rocker/shiny-verse:latest
# system libraries of general use
RUN apt-get update && apt-get install -y \
    sudo \
    pandoc \
    pandoc-citeproc \
    libcurl4-gnutls-dev \
    libcairo2-dev \
    libxt-dev \
    libssl-dev \
    libssh2-1-dev 
# install R packages required 
# (change it dependeing on the packages you need)
RUN R -e "install.packages('shiny', repos='http://cran.rstudio.com/')"
RUN R -e "install.packages('shinydashboard', repos='http://cran.rstudio.com/')"
RUN R -e "devtools::install_github('andrewsali/shinycssloaders')"
RUN R -e "install.packages('lubridate', repos='http://cran.rstudio.com/')"
RUN R -e "install.packages('magrittr', repos='http://cran.rstudio.com/')"
RUN R -e "install.packages('glue', repos='http://cran.rstudio.com/')"
RUN R -e "install.packages('DT', repos='http://cran.rstudio.com/')"
RUN R -e "install.packages('plotly', repos='http://cran.rstudio.com/')"
# copy the app to the image
COPY project.Rproj /srv/shiny-server/
COPY app.R /srv/shiny-server/
COPY R /srv/shiny-server/R
COPY data /srv/shiny-server/data
# select port
EXPOSE 3838
# allow permission
RUN sudo chown -R shiny:shiny /srv/shiny-server
# run app
CMD ["/usr/bin/shiny-server.sh"]

To build the docker image you can run on the console (where the Dockerfile is located):

docker build -t my-shiny-app .

To create a container just run:

docker run --rm -p 3838:3838 my-shiny-app

You can share your image on Docker Hub or as a .tar file.