[Bug]: Upgrade process re-renders config.php in a less readable/useable fashion

[Keeper-of-the-Keys]

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

It seems that processes like upgrades that "re-render" config.php make it less readable.

Config variable constants (like PDO::MYSQL_ATTR_SSL_CA becomes 1009) get rendered into their actual values which is both less human readable and can also break a configuration in the far-fetched case that they change the numbering of these attributes upstream.

In addition to the above comments are also removed which may not be ideal.

Steps to reproduce

1. On a not fully up to date installation of nextcloud configure SSL for the database connection by adding the following as per the documentation

'dbdriveroptions' => [
//  \PDO::MYSQL_ATTR_SSL_KEY => '/../ssl-key.pem',
//  \PDO::MYSQL_ATTR_SSL_CERT => '/../ssl-cert.pem',
  \PDO::MYSQL_ATTR_SSL_CA => '/etc/ssl/certs/ca-certificates.crt',
  \PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT => true,
],

(in my case I used LE so I only needed to set the CA and VERIFY_SERVER_CERT)
2. Run a nextcloud update
3. Look at the contents of config.php it is now and any comments that were in it are gone:

'dbdriveroptions' => 
  array (
    1009 => '/etc/ssl/certs/ca-certificates.crt',
    1014 => true,
  ),

Expected behavior

At least constant names (\PDO::....) should have been preserved and ideally comments should too.

Nextcloud Server version

31

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.3

Web server

Apache (supported)

Database engine version

MariaDB

Additional info

Discovered with 31.0.7 -> 31.0.9.1 upgrade, verified by rolling the vm back and doing it again.

While I understand the process that most likely causes this (config.php is re-rendered from the state of nextcloud during the update, thus we only have the actual data structure), it seems to me that if this is something that can't be changed a comment header needs to be added that warns that documentation in the form of comments will not be preserved in upgrades or alternatively that only comments outside of the $CONFIG array can be preserved.

I do think that preserving constant names is critical.

[kesselb]

Thanks for your report 👍

It's the parsed version of the configuration written back. Unsure if we can change that. With https://docs.nextcloud.com/server/latest/admin_manual/configuration_server/config_sample_php_parameters.html#multiple-merged-configuration-files there's also a solid workaround available.

[Keeper-of-the-Keys]

Yeah I figured as much which is why I suggested adding a header warning about comment-documentation.

As for constant names that one is harder but I believe that one is important enough to look at, where does this code live?

[Keeper-of-the-Keys]

@kesselb I tested your suggestion of using mysql.config.php and that file remained unchanged.

Maybe a header like this should be placed in config.php

# This file gets modified by automatic processes and all lines that are not
# active code are lost during that process.
# If you want to document things with comments add your settings in a
# something.config.php file which will automatically be included.
#
# See example.config.sample.php

As for the constant names I hope to test some code today or tomorrow, when using a file that gets included they are rendered into numbers which IMHO makes the config file less human readable.

[kesselb]

where does this code live?

In https://github.com/nextcloud/server/blob/master/lib/private/Config.php