ENTRYPOINT vs CMD
The ENTRYPOINT specifies a command that will always be executed when the container starts. The CMD specifies arguments that will be fed to the ENTRYPOINT. FROM debian:wheezy ENTRYPOINT ["/bin/ping"] CMD ["localhost"] $ docker run -it img google.com Ref: https://stackoverflow.com/questions/21553353/what-is-the-difference-between-cmd-and-entrypoint-in-a-dockerfile/34245657#34245657