Docker-compose set user and group on mounted volume

Question

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 directo

Answer 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.

Answer 2

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

1. 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
   

2. 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

Answer 3

The bad news is there's no owner/group/permission settings for volume

Answer 4

Adding rw to the end of the volume mount worked for me:

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