The ENTRYPOINT instruction is used to configure a docker image to run like an application or a command. For example, we can use the ENTRYPOINT instruction to make an image that displays help for the curl command. Consider this Dockerfile:

# ENTRYPOINT instruction Dockerfile for Docker Quick Start
FROM alpine
RUN apk add curl
ENTRYPOINT ["curl"]
CMD ["--help"]

We can run the container image with no overriding CMD parameter and it will show help for the curl command. However, when we run the container with a CMD override parameter, in this case, a URL, the response will be to curl the URL. Take a look:

When run parameters are provided to a container that has the exec form of the ENTRYPOINT command, those parameters will be appended to the ENTRYPOINT instruction, overriding anything provided in a CMD instruction. In this example, --help...