Dockerfile: running /usr/sbin/init [closed]

Question

Dockerfile

FROM centos:7
COPY docker-entrypoint.sh /data/
ENTRYPOINT ["/data/docker-entrypoint.sh"]

docker-entrypoint.sh

exec /usr/sbin/init && systemctl restart autofs %% python /data/myapp.py

I need to run /usr/sbin/init as the first command then run subsequent commands such as systemctl restart autofs and python myapp.py

I cant seem to get all working inside docker-entrypoint.sh because /usr/sbin/init does not return

if i change docker-entrypoint.sh to

/usr/sbin/init &
systemctl restart autofs && python /data/myapp.py

it fails with error in d-bus

what can i do so the container runs /usr/sbin/init, systemctl restart autofs and python /data/myapp.py in that order when "docker run" is executed?

Is there any other ways to run commands after /usr/sbin/init is executed? i've tried putting systemctl as CMD in Dockerfile

FROM centos:7
ENTRYPOINT ["/usr/sbin/init"]
CMD ["systemctl restart autofs"]

but CMD is never executed

Answer 1

Declaring

ENTRYPOINT ["/usr/sbin/init"]
CMD ["systemctl"]

Will result in:

/usr/sbin/init systemctl

In other words, the ENTRYPOINT directive sets the executable which is used to execute the command given from the COMMAND directive.

The default ENTRYPOINT is /bin/sh -c so /bin/sh -c /data/docker-entrypoint.sh should work, if /data/docker-entrypoint.sh contains:

/usr/sbin/init
systemctl restart autofs
python /data/myapp.py

That means: You don't have to change the ENTRYPOINT

If you change the the ENTRYPOINT to /data/docker-entrypoint.sh than it should contain something like:

/usr/sbin/init
systemctl restart autofs
python /data/myapp.py
# run the command given as arguments from CMD
exec "$@"

reference