-mkdir -p workbench/generated
-tar -c -z -f workbench/generated/workbench.tar.gz -C ../apps workbench
-docker build -t arvados/workbench workbench
+if ! docker images > /dev/null 2>&1
+then
+ echo >&2 "WARNING: docker could not be run."
+ echo >&2 "Please make sure that:"
+ echo >&2 " * You have permission to read and write /var/run/docker.sock"
+ echo >&2 " * a 'cgroup' volume is mounted on your machine"
+ echo >&2 " * the docker daemon is running"
+ build_ok=false
+fi