Docker-compose set user and group on mounted volume

问题

I'm trying to mount a volume in docker-compose to apache image. The problem is, that apache in my docker is run under www-data:www-data but the mounted directory is created under root:root. How can I specify the user of the mounted directory?

I tried to run command setupApacheRights.sh. chown -R www-data:www-data /var/www but it says chown: changing ownership of '/var/www/somefile': Permission denied

services:
    httpd:
        image: apache-image
        ports:
            - "80:80"
        volumes:
            - "./:/var/www/app"
        links:
            - redis
        command: /setupApacheRights.sh

I would prefer to be able to specify the user under which it will be mounted. Is there a way?

回答1:

First determine the uid of the www-data user:

$ docker exec DOCKER_CONTAINER_ID id
uid=100(www-data) gid=101(www-data) groups=101(www-data)

Then, on your docker host, change the owner of the mounted directory using the uid (100 in this example):

chown -R 100 ./

Dynamic Extension

If you are using docker-compose you may as well go for it like this:

$ docker-compose exec SERVICE_NAME id
uid=100(www-data) gid=101(www-data) groups=101(www-data)
$ chown -R 100 ./

You can put that in a one-liner:

$ chown -r $(docker-compose exec SERVICE_NAME id -u) ./

The -u flag will only print the uid to stdout.

回答2:

If you're using Docker, you want this directly in your config rather than performing manual steps every time you build an image. The bad news is there's no owner/group/permission settings for volume as of 2019 😢. The good news is there's a trick that does let you bake it into your config 🎉.

You simply need to create the directory with desired settings in your Dockerfile, which means the directory will be present before docker-compose mounts to the location. When the mount occurs, the directory's permissions will be retained.

Dockerfile:

# setup folder before switching to user
RUN mkdir /volume_data
RUN chown postgres:postgres /volume_data
USER postgres

docker-compose.yml

volumes:
   - /home/me/postgres_data:/volume_data

source

回答3:

To achieve the desired behavior without changing owner / permissions on the host system do the following steps.

add the definition to your docker-compose.yml

user: "${UID}:${GID}"

so your file could look like this

php: # this is my service name
    user: "${UID}:${GID}" # we added this line to get a specific user / group id
    image: php:7.3-fpm-alpine # this is my image
# and so on

set the values in your .env file
```
UID=1000
GID=1001
```

Now your user in the container has the id 1000 and the group is 1001 and you can set that differently for every environment.

If you don't use docker-compose or want to know more different approaches to achieve this have a read through my source of information: https://dev.to/acro5piano/specifying-user-and-group-in-docker-i2e

来源：https://stackoverflow.com/questions/40462189/docker-compose-set-user-and-group-on-mounted-volume

标签

Docker

docker-compose