I installed a Wordpress website with the wordpress Docker image, and then installed my themes. All works well, but when I want to update Wordpress later on, I get this message:
To perform the requested action, WordPress needs to access your web server. Please enter your FTP credentials to proceed. If you do not remember your credentials, you should contact your web host.
The Wordpress container is not running an FTP server on the web root. How could I solve this problem?
PS: I have my web root in a data container, shared among different containers.
PS2: I am planning on storing several Wordpress websites in the same host. Is there also a solution that is compatible with this?
The key is to make sure your web server is the owner of the directory WordPress is installed in (and its sub-directories). You're seeing an error because your web server doesn't have the proper privileges to write to your directories.
I recommend running a chown -R user:group /path/to/wordpress, substituting the user and group with your server's info.
来源：https://stackoverflow.com/questions/30396506/updating-wordpress-inside-a-container-no-ftp-access