dockerfile cmd and entrypoint

very confusing, poor design IMHO


Dockerfile:

FROM ubuntu
ENV myname "pierre"
ENTRYPOINT ["/bin/bash", "-c", "echo hello ${myname}"]


docker built -t hello01 .
docker run hello01





FROM ubuntu
ENTRYPOINT ["sleep"]

docker built -t hello02 .
docker run hello02

#this sleep for 5s
docker run hello02 5

#this gives error because parameter is missing
docker run hello02



FROM ubuntu
ENTRYPOINT ["sleep"]
CMD ["5"]


this version uses a default time of 5, if not specified in command line
"docker run hello02" will sleep for 5
"docker run hello02 10" will sleep for 10