SemanticMediaWiki .smw.json file not persisted across container restarts

[tosfos]

In Canasta deployments, the SemanticMediaWiki update key file (.smw.json) is not being persisted across container restarts or recreations, causing ERROR_SCHEMA_INVALID_KEY errors. While Canasta (by default) automatically runs update.php --quick on startup, this does not regenerate the missing .smw.json file, requiring manual intervention to restore it.

Root Cause

The .smw.json file is stored in /var/www/mediawiki/w/canasta-extensions/SemanticMediaWiki/.smw.json, but the canasta-extensions directory is not mounted as a persistent volume in the Docker Compose configuration.

This will affect Kubernetes deployments as well.

Expected Behavior

The .smw.json file should persist across container restarts without manual intervention.

Actual Behavior

The .smw.json file is lost after container recreation because:

• The canasta-extensions directory is not a mountpoint
• The directory exists only in the container filesystem layer
• No volume mapping exists for this directory in docker-compose.yml

Workaround

Users can configure SemanticMediaWiki to use a persistent location by adding to LocalSettings.php:

$smwgConfigFileDir = '/mediawiki/config/smw';

[yaronkoren]

Ah, fun with Semantic MediaWiki. Of course, it makes sense that SMW would need an "update key file" - it's a comical feature for a comical extension.

The YAML file syntax already supports defining "persistent directories", and SMW already has one - config/ . I don't know what goes in that directory right now, but it would appear that another option is to set the following:

$smwgConfigFileDir = __DIR__ . '/config';

I could be wrong, though; I'm not even sure if the two directories named "config" are unrelated.

Another option is to add a "persistent files" YAML parameter just for this one file, and yet another option is to add special hardcoded handling for this one file - just like other SMW functionality already gets special hardcoded handling. That last option might ironically be the least hacky.

What do you think?

[tosfos]

Seems like a better idea if it works, but I don't think it will. My guess is that the directory does not exist at build time. Also if I understand this correctly, that directory will be created within canasta-extensions which isn't mounted and therefore won't persist anyway.
And my assumption is that this move and symlink creation fails silently.

[yaronkoren]

Sorry, which of the three options are you commenting on?

[tosfos]

Also, this continue will mean that extension installed via composer will not be able to use persistent directories, patches or additional steps.

[tosfos]

Sorry, which of the three options are you commenting on?

Right. I was commenting on:

$smwgConfigFileDir = __DIR__ . '/config';

[tosfos]

The other two options seem like they can work. But I'm not sure what the advantage is and either way the persistent directories handling needs to be reworked.

[yaronkoren]

Well, if the handling of persistent directories is broken, then that's of course a separate (and bigger) issue. Maybe we should re-discuss this once that's fixed, assuming it indeed is not working.

[tosfos]

OK. I created CanastaWiki/CanastaBase#36 and CanastaWiki/CanastaBase#35.