Allow to provide plugin configuration files in html/config

[liayn]

Studiing the code in https://github.com/roundcube/roundcubemail/blob/master/program/lib/Roundcube/rcube_plugin.php#L167 reveals that it is possible to provide the config for plugins through any path (therefore also `/var/www/html/config/.inc.php).
This is great, because it means we do not need to touch the code/content of plugins at all.

To easy deployment it would therefore be helpful, if the entry-script would also copy such config files from the /var/roundcube/ folder.

I'd suggest to add the possibility to provide those files in /var/roundcube/plugin-config/ and to simply copy those over to /var/www/html/config/

If this suggestion is welcome, I'd provide a PR.

Note: This is mostly important for php-fpm use cases.

[pabzm]

rcube_plugin#load_config() only looks for $pluginname.inc.php if plugins/$pluginname/$configfilename doesn't exist, but some plugins do provide a default config with that name, so for those plugins this solution would work.

In #381 we introduced pre-setup and post-setup tasks, which (should) allow to provide a config for all plugins. Admittedly requiring a little bit of manual work, but I would not like to introduce a more automated solution which then only works for a subset of plugins.

[liayn]

rcube_plugin#load_config() only looks for $pluginname.inc.php if plugins/$pluginname/$configfilename doesn't exist, but some plugins do provide a default config with that name, so for those plugins this solution would work.

Works flawlessly with managesieve and password plugins. :-)

As noted in #397 (comment) the goal must be to separate concerns. Code, Configuration, public assets.

If someone is interested, your solution for both issues now is:

Dockerfile:

FROM roundcube/roundcubemail:latest-fpm

ENV ROUNDCUBEMAIL_PLUGINS=archive,zipdownload,password,managesieve
ENV ROUNDCUBEMAIL_UPLOAD_MAX_FILESIZE=100M

COPY php.ini $PHP_INI_DIR/conf.d/xxx-reelworx.ini
COPY config.php /var/roundcube/config/
COPY plugin-config /var/roundcube/plugin-config/
COPY images /var/roundcube/assets/images/
COPY --chmod=0755 setup.sh /entrypoint-tasks/post-setup/

setup.sh:

#!/usr/bin/env bash

cp -r /var/roundcube/plugin-config/* /var/www/html/config/
cp -r /var/roundcube/assets/* /var/www/html/public_html/

plugin-config contains the config files for the plugins, like password.inc.php

[sclu1034]

but some plugins do provide a default config with that name

I have just had the opposite experience. Plugins generally seem to only provide a .dist template config. But for composer plugins, the roundcube/plugin-installer copies these to a non-.dist file during installation, IFF no config file named ${pluginname}.inc.php exists. And that new file seems to always overwrite the configuration that this Docker image supports.

To fix that, I'm setting RCUBE_CONFIG_PATH: ./config:/var/roundcube/config, which enables the plugin installer to find files in the image's custom path and therefore won't copy from the plugin templates.
I haven't checked if this makes Roundcube count my config files double (once from the entrypoint creating an include() for them and a second time because they're now in Roundcube's search paths), but they're idempotent, so no issues if they are.