https://linear.app/n8n/issue/PAY-933/set-up-leader-selection-for-multiple-main-instances
- [x] Set up new envs
- [x] Add config and license checks
- [x] Implement `MultiMainInstancePublisher`
- [x] Expand `RedisServicePubSubPublisher` to support
`MultiMainInstancePublisher`
- [x] Init `MultiMainInstancePublisher` on startup and destroy on
shutdown
- [x] Add to sandbox plans
- [x] Test manually
Note: This is only for setup - coordinating in reaction to leadership
changes will come in later PRs.
This change ensures that things like `encryptionKey` and `instanceId`
are always available directly where they are needed, instead of passing
them around throughout the code.
This PR adds a message for queue mode which triggers an external secrets
provider reload inside the workers if the configuration has changed on
the main instance.
It also refactors some of the message handler code to remove cyclic
dependencies, as well as remove unnecessary duplicate redis clients
inside services (thanks to no more cyclic deps)
