How to fix file permissions on wp-content with official wordpress image for docker-compose

You can modify your ./entrypoint.sh script to run the default entrypoint script of the original image after it executes your chown command:

#!/bin/bashecho Fixing permissions...chown -R www-data:www-data /var/www/html/wp-content/docker-entrypoint.sh apache2-foreground

From Docker's documentation the command you should be using is RUN.

Don’t confuse RUN with CMD. RUN actually runs a command and commits the result; CMD does not execute anything at build time, but specifies the intended command for the image.

So the line in your Dockerfile should be:RUN chown -R www-data:www-data /var/www/html/wp-content

Also, to decrease the number of layers created and the size of your image, I'd chain as many of the RUN commands as possible. For example (not tested):

FROM wordpress:5.1.1# install dos2unix (fix problem between CRLF and LF) and increase upload limitRUN apt-get update -y && \    apt-get install -y dos2unix && \    touch /usr/local/etc/php/conf.d/uploads.ini \    && echo "upload_max_filesize = 10M;" >> /usr/local/etc/php/conf.d/uploads.ini && \    chown -R www-data:www-data /var/www/html/wp-content# fix permissions issuesCOPY entrypoint.sh /RUN dos2unix /entrypoint.sh && \    chmod +x /entrypoint.shENTRYPOINT ["/entrypoint.sh"]

This is due to the way the WordPress Docker image is created.

I created a Pull Request to make the wp-content folder belong to www-data when it is (or some of its subfolders) shared using a volume.

Before it is merged (it if is), you can create your own WordPress Docker image to integrate my change. Take one of the folder on https://github.com/docker-library/wordpress (choose PHP version, and then webserver parameters).

1. Create a docker/wordpress folder in your project.
2. Copy the two raw files (Dockerfile and docker-entrypoint.sh) from GitHub into that folder.
3. Replace these lines in docker-entrypoint.sh:

        if [ "$(id -u)" = '0' ] && [ "$(stat -c '%u:%g' .)" = '0:0' ]; then            chown "$user:$group" .        fi

by:

        if [ "$(id -u)" = '0' ]; then            chown -R "$user:$group" .        fi