Docker 卷装空

Question

I'm making an image to host a PHP application. I'm using COPY to populate /var/www/html with the app files and creating a VOLUME /var/www/html to be able to mount the dir on the host and edit files like config.

But:

1. When I mount the volume on docker-compose.yml, the directory is empty.

2. When I omit the "volmue" entry on the docker-compose.yml and connect with the container shell, the directory /var/www/html is filled.

I already read tons of examples and documentations but, sincerely, don't know what is wrong.

dockerfile:

FROM php:8.0-apache-buster
LABEL description="OCOMON 3.2 Frontend (noDB)"
RUN docker-php-ext-install pdo_mysql

WORKDIR /var/www/html/ocomon

COPY ./ocomon .

VOLUME /var/www/html/ocomon

docker-compose.yml:

version: '3.5'
services:
    ocomon:
        image: ocomon:3.2
        container_name: ocomon
        volumes:
            - ./volumes/ocomon/ocomon:/var/www/ocomon
        ports:
            - 4682:80

Answer 1

Assuming your host's directory is ${PWD}/www/html , then you need only provide the volumes value in docker-compose.yml and it should be:

Dockerfile :

FROM php:8.0-apache-buster
LABEL description="OCOMON 3.2 Frontend (noDB)"
RUN docker-php-ext-install pdo_mysql

WORKDIR /var/www/html/ocomon

COPY ./www/html/ocomon .

and: docker-compose.yml :

version: '3.5'
services:
  ocomon:
    image: ocomon:3.2
    container_name: ocomon
    volumes:
    - ${PWD}/www/html:/var/www/html
    ports:
    - 4682:80

Explanation

• Dockerfile VOLUMES creates a volume in the image. By following WORKDIR (which always create if the path does not exist), with VOLUME , you overwrite whatever was either in (or created by WORKDIR ). NOTE this is done during image build .

• Docker Compose volumes mounts a directory from the host into the image. The syntax is volumes: - ${HOST_PATH}:${IMAGE_PATH} . NOTE this is done during image run .