in order to facilitate development, we plan to create a LNMP environment based on docker, which makes it much more convenient to change computers or unify the team"s development environment.

choreographed a docker-compose.yaml file with nginx, php-fpm, mysql, redis and other services. All of them have been done except php-fpm

tell me about the process:

• first of all, pull"s official php image php:7.x-fpm . Create images and containers, and have no problems connecting to other containers
.
• but the PHP extension (extension) supported by this image is too few, and many commonly used ones do not (such as the gd library)
• is installed by setting RUN docker-php-ext-install gd in Dockerfile, indicating that libpng library
is missing.
• enter the container and install it with yum install-y libpng , prompting yum is an unknown command
• installs yum through rpm xxx , prompting that rpm is an unknown command.

then change the way of thinking and plan to create your own php-fpm image based on the centos image, so:

• pull official centos 7.x image, enter the container to download the php source code package, and compile and install it smoothly
• start the container and find that the php-fpm service
cannot be opened automatically.
• in docker-compose , command and entrypoint define commands (not at the same time):
  / path/to/sbin/php-fpm-y / path/to/etc/php-fpm.conf . When the container starts, the service fails to start, and the prompt message is equivalent to entering: php-fpm-h , all related parameters
.

I feel that this problem is because php-fpm is in the sbin directory and can only be run by a superuser, but executing command or entrypoint when the container is started is not a superuser, so it fails
, which causes me to enter php container to manually open the service every time I start container orchestration

I really don"t know what to do. I hope all of you can give me some hints:
1. How do I make the centos container automatically open the php-fpm service when it starts?
2. Or instead of using this idea, we can use other solutions

Thank you very much, thank you ~