installer.pl does not check for changed file Kernel/Config.pm

[bschmalhofer]

During testing for OTOBO 10.1.1 Beta2 @svenoe noticed database connection failures while running installer.pl . This was almost certainly caused by the web server process having still loaded an unchanged version of Kernel::Config. This is relevant as Kernel/Modules/Installer.pm writes the new database credentials into that file.

The big mystery is why this behavior was noticed only now. Doing a test installation with OTOBO 10.1.1 Beta2 showed the same error.

A possible solution is to check for every request whether Kernel/Config.pm has changed. This is basically the same check as done in Kernel::Config::Defaults:;new() for possibly changed ZZZ*.pm files.

While we are at it, we should also check for explicit use Kernel::Config; statements. These statements should be avoided unless they are really necessary. But they are not really the culprit as the object manager calls under the hood also require Kernel::Config.

[bschmalhofer]

No new insights turned up, why this wasn't an issue before.

For fixing the bug I added the refresh of Kernel/Config.pm in otobo.psgi . Care had to be taken that Kernel/Config.pm is in the refresh cache before the first check. Otherwise the following situation could arise:

1. Kernel::Config.pm is loaded in process A, but not in refresh cache
2. Kernel/Config.pm is modified in process B
3. Kernel/Config.pm is checked in process A, but not reloaded is this is the first check

[bschmalhofer]

I tested installer.pl with a local Apache and the apache2-httpd-cgi.include.conf configuration. Installing was without hassle. But there were errors after the installation was completed. Looks like we need a bit more testing and maybe fixing.

[bschmalhofer]

Looked again what Module::Refresh::refresh_module_if_modified() is actually doing. There is no refreshing when the module has been loaded and changed after the last time it has been encountered by Module::Refresh. So the current approach is;

1. require $PMFile; load when it wasn't already loaded
2. Module::Refresh->refresh_module_if_modified('Kernel/Config.pm'); either remember the timestamp, do nothing, or reload

Made the changes and did quick tests of installer.pl.

• Apache2 with apache2-httpd.include.conf
• Apache2 with apache2-httpd-cgi.include.conf
• Gazelle running in Docker

The quick tests looked fine and the test suite looked fine too. Except #1587.
Thus I merged the changes into rel-10_1.

[svenoe]

Can this be closed? We are already one step further anyways, I guess, aren't we?

[bschmalhofer]

The reloading of Kernel/Config.pm appears to be more sane now. Note that there was yet another iteration handled in issue #1594. Closing this issue.