How to modify files in wordpress docker volume? - wordpress

Question

This is my docker-composer.yml for wordpress:
version: '3.3'
services:
db:
image: mysql:5.7
volumes:
- db_data:/var/lib/mysql
restart: always
environment:
MYSQL_ROOT_PASSWORD: somewordpress
MYSQL_DATABASE: wordpress
MYSQL_USER: wordpress
MYSQL_PASSWORD: wordpress
wordpress:
depends_on:
- db
image: wordpress:latest
volumes:
- ./all:/var/www/html
ports:
- "8000:80"
restart: always
environment:
WORDPRESS_DB_HOST: db:3306
WORDPRESS_DB_USER: wordpress
WORDPRESS_DB_PASSWORD: wordpress
WORDPRESS_DB_NAME: wordpress
phpmyadmin:
image: phpmyadmin/phpmyadmin:latest
ports:
- "8084:80"
links:
- db:db
volumes:
db_data: {}
The folder all contains all the files that ship from the wordpress docker image. However, they all have user/group www-data:www-data and the permission of the files is 644 and from folders 755, i.e. even if I add myself to the www-data group I have no right to modfiy or create files.
My research:
I found at write in shared volumes docker that someone had the opposite problem, he created files and his docker image could not access it. The solution seems to be to run docker and create a file with user www-data - but I don't see how I can apply this to my problem.
I tried to add user: "1000:1000 in the worpdress service inside docker-composer.yml, in hope, that all file permissions set by docker would be from my user. However, I get 1000 lines of erros of this form:
wordpress_1 | tar: ./wp-admin: Cannot mkdir: Permission denied
wordpress_1 | tar: ./wp-admin/options-reading.php: Cannot open: No such file or directory

Answer 1

I ended up just to change the file permission of all files and folders from folder all to 777 recursively. Since this is only local development, there is no risk involved.
When I create a new file from my host it only has 644 permission, i.e. it can be read by from localhost but not edited, for that I would manually need to change the permission to 777.

Answer 2

A bit old of a thread but i also was looking on how to update files on a wordpress:latest container.
I ended using a docker cp on the file i need to change. For instance :
docker cp ./functions_edited.php 6666aa5bbd76:/var/www/html/wp-content/themes/twentytwentytwo/functions.php
to edit the theme functions on the running container.
This works for me since i don't need to persists my changes when the container dies and i need just to change a single file. Maybe this is not your use case.