Implement features for Keepalived integration

[nf-brentsaner]

A note for the community

• Please vote on this issue by adding a 👍 reaction to the original issue to help the community and maintainers prioritize this request
• If you are interested in working on this issue or have submitted a pull request, please leave a comment

Use Cases

When using e.g. KeepaliveD, HAProxy, etc. to load-balance/HA multiple Vector instances, it is desirable to implement health checks. This allows for dynamic balance membership or priority based on if Vector itself is actually running on a target address.

To accomplish this, there should be an option for:

1. an option on http_server that will respond to a GET with a static body text/bytes and specified status code
2. an option to filter out/not log bogus/improperly framed traffic from certain addresses/ranges/prefixes (e.g. for UDP socket, UDP syslog sources)

For no. 2, I've worked around it for now by configuring KeepaliveD to send a specific valid syslog message as its payload with certain identifiers unlikely to be encountered in real life and then filtering it out with a route.
However, given that there does not seem to be any way of avoiding a log entry when dropping an event or dealing with unexpected-formatting of received data (even if abort() is called, even with an explicitly or unspecified empty log message, and a bytes or vrl encoding is used), other balancing solutions aside from Keepalived may struggle with this.

For no. 1, I don't have any sort of ideal workaround. I suppose I could have the API listen on all addresses and do a GET to that but that's still pretty decoupled from an actual source that I'd want to verify is responding within a certain amount of time.

Attempted Solutions

(See above)

Proposal

(See above)

References

No response

Version

vector 0.56.0 (x86_64-unknown-linux-gnu 6817c02 2026-06-03 14:25:37.451398530)