Autostart Script for Docker Container

I want a script that starts if my container start in docker. I have a and a dockerfile.

I tried to change the command but it is the same or it didnt work. The file copy of the works and it runs.

In my Dockerfile is this code

COPY /etc/init.d/
RUN chmod +x /etc/init.d/
RUN /etc/init.d/

In my

update-rc.d starter defaults
echo "Hello"

This is the message that comes if it runs the

usage: update-rc.d [-n] [-f] <basename> remove
       update-rc.d [-n] [-f] <basename> defaults
       update-rc.d [-n] <basename> disable|enable [S|2|3|4|5]
                -n: not really
                -f: force

The disable|enable API is not stable and might change in the future.

I hope someone could help me

Source: StackOverflow