docker_app=$(find /Applications/ \
                  -name "Docker.app" -maxdepth 1 -mindepth 1 -type d)
if [ -z "$docker_app" ]; then
   echo "Installation of Docker for Mac"
   curl -o ~/Downloads/Docker.dmg -sL https://download.docker.com/mac/stable/Docker.dmg
   hdiutil verify ~/Downloads/Docker.dmg
   hdiutil attach ~/Downloads/Docker.dmg -nobrowse
   cp -R /Volumes/Docker/Docker.app /Applications/
   hdiutil detach /Volumes/Docker
   rm ~/Downloads/Docker.dmg
   sudo /Applications/Docker.app/Contents/MacOS/Docker --quit-after-install --unattended
fi