How to do livereload for php in Docker?

Question

Docker

Good day.
It's no secret that the main disadvantage of docker is the inconvenience of development: every time after changing files, you have to do docker cp in order to copy the changes to the container. However, volume would seem to provide the ability to link a directory in a container to a directory on the host machine.

FROM php:7.2.19-apache

VOLUME data /var/www/html
COPY data /var/www/html

# все остальные команды

The folder structure is like this:

- Dockerfile
- config
- data
-- app

After starting the container, I expect Docker to automatically update the corresponding directory (map "data" to "var/www/html", that is, analogous to "COPY data /var/www/html", that is, analogous to volume ./data:/var /www/html in docker-compose). However, this does not happen. I change the files, but the version in the container remains the same.
What did I do wrong, or is this how it should work? If so, is it possible to have docker automatically update directories on file changes on disk?

Answer 1

VOLUME is not analogous to the -v switch when starting a container or volume ./data:/var/www/html in docker-compose. It simply creates a disk storage for the container and maps it to /var/lib/docker/volumes.
To mount a local directory, you still need to use the -v switch for docker or the equivalent in docker-compose.