Dockerfile

# We use multi-stage build contexts to generate different versions of the image from one dockerfile
#  base: the complete software system is installed, non executable
#  app:  executable app
#
#   See https://medium.com/@tonistiigi/advanced-multi-stage-build-patterns-6f741b852fae 
#
# Note that ARG for image name needs to come before any FROM so it can be used in a FROM at the end
#
#   See https://docs.docker.com/engine/reference/builder/#understand-how-arg-and-from-interact
#

ARG image_name "base"

# built upon the rocker/tidyverse image, which includes remotes and shiny

FROM rocker/tidyverse:latest AS tidyverse

# set env vars

ARG SHINY_ACCOUNT ""
ARG SHINY_TOKEN ""
ARG SHINY_SECRET ""

ENV SHINY_ACCOUNT=""
ENV SHINY_TOKEN=""
ENV SHINY_SECRET=""



# Build args, default to the base image from the main branch

ARG event_sha "HEAD"

# Install ShinyDocker from github event that is triggering the build

RUN echo "Installing ShinyDocker from github at ref $event_sha"
RUN R -e "remotes::install_github('dapperstats/ShinyDocker', ref = '$event_sha')"

# Each image branches for specific run code

FROM tidyverse AS base-branch


FROM tidyverse AS app-branch

RUN R -e "library(ShinyDocker); setup_dir( )"
CMD ["R", "-e", "library(ShinyDocker); deploy_app( )"]

# Bring the branches together

FROM ${image_name}-branch AS final