feature: compose vmauth configuration from several sources

[vrutkovs]

Operator has VMUser objects to compose VMAuth configuration from multiple sources. Helm charts should allow composing vmauth configuration similarly.

Ideas:

• similar to vmuser, allow composing config from several configmaps (via labelselector). These would apply in lexographical order
• similar to systemd services allow specifying "dropins" - configmaps with bits of configuration to override / extend.

[AndrewChubatiuk]

it makes sense to create a feature request at VictoriaMetrics instead. we can actually improve our config reloader to make it crafting one config from multiple secrets, but suppose it's better to support loading users from multiple files natively

[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 5 days.

[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 5 days.