Not understanding what is happening when I try to execute two commands at runtime via CMD directive in `Dockerfile. I assumed that this should work:
CMD ["/etc/init.d/nullmailer", "start", ";", "/usr/sbin/php5-fpm"]
But it's not working. Container has not started. So I had to do it like this:
CMD ["sh", "-c", "/etc/init.d/nullmailer start ; /usr/sbin/php5-fpm"]
I don't understand. Why is that? Why first line is not the right way? Can somebody explain me these "CMD shell format vs JSON format, etc" stuff. In simple words.
Just to note - the same was with command: directive in docker-compose.yml, as expected.