julia_on_colab.md

In order to execute julia code on Colab, execute the following code snippet and then refresh:

%%shell
set -e

#---------------------------------------------------#
JULIA_VERSION="1.4.2" # any version ≥ 0.7.0
JULIA_PACKAGES="IJulia"
JULIA_PACKAGES_IF_GPU="CUDA"
JULIA_NUM_THREADS=4
#---------------------------------------------------#

if [ -n "$COLAB_GPU" ] && [ -z `which julia` ]; then
  # Install Julia
  JULIA_VER=`cut -d '.' -f -2 <<< "$JULIA_VERSION"`
  echo "Installing Julia $JULIA_VERSION on the current Colab Runtime..."
  BASE_URL="https://julialang-s3.julialang.org/bin/linux/x64"
  URL="$BASE_URL/$JULIA_VER/julia-$JULIA_VERSION-linux-x86_64.tar.gz"
  wget -nv $URL -O /tmp/julia.tar.gz # -nv means "not verbose"
  tar -x -f /tmp/julia.tar.gz -C /usr/local --strip-components 1
  rm /tmp/julia.tar.gz

  # Install Packages
  if [ "$COLAB_GPU" = "1" ]; then
      JULIA_PACKAGES="$JULIA_PACKAGES $JULIA_PACKAGES_IF_GPU"
  fi
  for PKG in `echo $JULIA_PACKAGES`; do
    echo "Installing Julia package $PKG..."
    julia -e 'using Pkg; pkg"add '$PKG'; precompile;"'
  done

  # Install kernel and rename it to "julia"
  echo "Installing IJulia kernel..."
  julia -e 'using IJulia; IJulia.installkernel("julia", env=Dict(
      "JULIA_NUM_THREADS"=>"'"$JULIA_NUM_THREADS"'"))'
  KERNEL_DIR=`julia -e "using IJulia; print(IJulia.kerneldir())"`
  KERNEL_NAME=`ls -d "$KERNEL_DIR"/julia*`
  mv -f $KERNEL_NAME "$KERNEL_DIR"/julia  

  echo ''
  echo "Successfully installed `julia -v`!"
  echo "Please reload this page (press Ctrl+R, ⌘+R, or the F5 key) then"
  echo "jump to the 'Checking the Installation' section."
fi

Additional Julia packages can be installed by providing them in space separated values in JULIA_PACKAGES. Credits: Julia for Pythonistas