Docker NGINX - PHP-FPM Cross Container Permissions? - docker

Question

I'm setting up a wordpress stack and having cross file permissions.
When using docker-compose up permissions seem not to be a problem but when using local docker swarm and using docker stack deploy, nginx gives me a 403 for file permission errors. When inspecting both the nginx:alpine container and the wordpress:php7.1-fpm-alpine container, i do indeed see that the containers each have different permission, on the nginx side it marks the files inside var/www/html as owned by user and group id 82 while on the php7.1 they are owned by www-data.
How can I make sure permission is correct across containers? The files are being bind mounted from the host.
```
version: '3'
services:
nginx:
depends_on:
- wordpress
image: private/nginx
build:
context: ./stack/nginx
volumes:
- "wordpress:/var/www/html"
ports:
- 80:80
wordpress:
depends_on:
- mysql
image: private/wordpress
build:
context: ./stack/wordpress
volumes:
- "wordpress:/var/www/html"
environment:
WORDPRESS_DB_USER: wordpress
WORDPRESS_DB_PASSWORD: password
mysql:
image: mariadb
volumes:
- "mysql:/var/lib/mysql"
environment:
MYSQL_ROOT_PASSWORD: password
MYSQL_DATABASE: wordpress
MYSQL_USER: wordpress
MYSQL_PASSWORD: password
volumes:
wordpress:
driver: local
driver_opts:
type: none
o: bind
device: "${PWD}/wordpress"
mysql:
```

Answer 1

For anyone else who comes across this question and has no solution,
this is how I approached the situation.
I added the following to my dockerfile, it creates a new www-datagroup AND user with the same id as the id that is used for the www-data user 82 & group 82 in the php-fpm image.
RUN set -x ; \
addgroup -g 82 -S www-data ; \
adduser -u 82 -D -S -G www-data www-data && exit 0 ; exit 1
To my docker file for nginx.
and in my nginx.conf i set the nginx worker user to the newly created ww-data user.
user www-data;