minor clean up of Dockerfile

Author: hturner

Dockerfile

@@ -1,29 +1,31 @@
-FROM mcr.microsoft.com/devcontainers/cpp:dev-ubuntu
-
-# Update and install necessary dependencies
-# (software-properties-common installed for apt-add-repository)
-RUN sed -i.bak "/^#.*deb-src.*universe$/s/^# //g" /etc/apt/sources.list \
-    && apt-get update \
-    && apt-get install -y --no-install-recommends \
-      software-properties-common \
-      subversion \
-    && add-apt-repository --enable-source --yes "ppa:marutter/rrutter4.0" \
-    && wget -qO- https://cloud.r-project.org/bin/linux/ubuntu/marutter_pubkey.asc | tee -a /etc/apt/trusted.gpg.d/cran_ubuntu_key.asc \
-    && apt-get update \
-    && apt-get build-dep -y r-base-dev \
-    && apt-get install -y r-base-dev \
-    && rm -rf /var/lib/apt/lists/*
-
-# Install R packages, with dynamic r-universe URL
-RUN Rscript -e "runiverse <- sprintf('r-universe.dev/bin/linux/%s-%s/%s/', \
-                                 system2('lsb_release', '-sc', stdout = TRUE), \
-                                 R.version\$arch, \
-                                 substr(getRversion(), 1, 3)); \
-                print('Installing packages...'); \
-                install.packages(c('languageserver', 'httpgd'), \
-                 repos = c(runiverse = paste0('https://cran.', runiverse), \
-                           nx10 = paste0('https://nx10.', runiverse))); \
-                print('Packages installed.')"
-
-ARG CONTAINER_VERSION
-ENV CONTAINER_VERSION=${CONTAINER_VERSION}
+FROM mcr.microsoft.com/devcontainers/cpp:dev-ubuntu
+
+# Update and install necessary dependencies
+# (software-properties-common installed for apt-add-repository)
+RUN sed -i.bak "/^#.*deb-src.*universe$/s/^# //g" /etc/apt/sources.list \
+    && apt-get update \
+    && apt-get install -y --no-install-recommends \
+      software-properties-common \
+      subversion \
+    && add-apt-repository --enable-source --yes "ppa:marutter/rrutter4.0" \
+    && wget -qO- https://cloud.r-project.org/bin/linux/ubuntu/marutter_pubkey.asc | tee -a /etc/apt/trusted.gpg.d/cran_ubuntu_key.asc \
+    && apt-get update \
+    && apt-get build-dep -y r-base-dev \
+    && apt-get install -y r-base-dev \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
+
+# Install R packages, with dynamic r-universe URL
+RUN Rscript -e "runiverse <- sprintf('r-universe.dev/bin/linux/%s-%s/%s/', \
+                                 system2('lsb_release', '-sc', stdout = TRUE), \
+                                 R.version\$arch, \
+                                 substr(getRversion(), 1, 3)); \
+                print('Installing packages...'); \
+                install.packages(c('languageserver', 'httpgd'), \
+                 repos = c(runiverse = paste0('https://cran.', runiverse), \
+                           nx10 = paste0('https://nx10.', runiverse))); \
+                print('Packages installed.')"
+
+# Define env var used in GitHub Actions that build and deploy container
+ARG CONTAINER_VERSION
+ENV CONTAINER_VERSION=${CONTAINER_VERSION}