docker 挂载卷，但将文件保留在 docker 容器内

Question

I use Dockerfile to build an image of php, but as the default, PHP don't have a php.ini file. So I need to create it. Now I have three ways to do this:

1. use RUN command in Dockerfile RUN cp /usr/local/etc/php/php.ini-production /usr/local/etc/php/php.ini . But this way still use a default setting, I can't edit it (or edit it and commit container).

2. use COPY command in Dockerfile COPY php.ini /usr/local/etc/php/php.ini . OK, now I can edit the config and then build image, but if I need to change some setting, I need rebuild image

3. use volumn args, add this in docker-compose.yml - $PWD/php/conf.d:/usr/local/etc/php/conf.d/my_config . By this way, I can edit php.ini anytime and just reload config file. But, the best way I wonder is - $PWD/php/conf.d:/usr/local/etc/php/conf.d . the first way will create a new sub folder in docker container, the second way will delete the *.ini file that originally in the folder

I want to know is here some way that could mount volumn and don't delete the file in container (the second way of 3 but don't delete file)

Answer 1

Actually the files are not deleted from the subfolder. The volume is mounted over it.

Reference

What you can do is, assign a separate folder for your *.ini files, and reference it from the main php.ini file. So every time you reload php, it goes to php.ini and from there it gets your dedicated config folder and loads all the *.ini files from there.