in_calyptia_fleet: fix registering agent after first invocation.

[pwhelan]

Summary

Fix a bug where calyptia fleet agents will not correctly register after the first time it is run.

Description

The calyptia fleet plugin stores the initial configuration that is used to invoke fluent-bit inside a file called header.conf (it only stores the configuration for the custom calyptia plugin) and makes use of it in further executions. The plugin also resolves the fleet_name into a fleet_id. This fleet_id though is not known on further executions and due to how it is resolved it would never be resolved in time to register the agent on subsequent executions.

THis fix simply adds the fleet_id to this header.conf so it can be used in subsequent executions beyond the first so it can register fluent-bit with the calyptia frontend.

---

Enter [N/A] in the box, if an item is not applicable to your change.

Testing
Before we can approve your change; please submit the following in a comment:

• Example configuration file for the change
• Debug log output from testing the change

• Attached Valgrind output that shows no leaks or memory corruption was found

If this is a change to packaging of containers or native binaries then please confirm it works for all targets.

• Run local packaging test showing all targets (including any new ones) build.
• Set ok-package-test label to test for all targets (requires maintainer to do).

Documentation

• Documentation required for this feature

Backporting

• Backport to latest stable release.

---

Fluent Bit is licensed under Apache 2.0, by submitting this pull request I understand that this code will be released under the terms of that license.