Add Prometheus metrics to the boundary log proxy for observability:
- batches_dropped_total (reason: buffer_full, forward_failed)
- logs_dropped_total (reason: buffer_full, forward_failed,
boundary_channel_full, boundary_batch_full)
- batches_forwarded_total
Also add BoundaryStatus to the BoundaryMessage envelope so boundary
can report dropped log counts as a separate wire message. The agent
records these as Prometheus metrics, making boundary-side data loss
visible. Backwards compatibility for older versions of boundary is maintained.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Extend the wire protocol for the boundary <-> agent unix socket with
a message envelope.
The envelope creates a boundary <-> agent data path that is separate
from the agent <-> coderd path. This lets boundary send operational
metadata (drop counts, configuration like jail type, capabilities)
that the agent can act on locally (e.g. Prometheus metrics) or use
to enrich outbound requests, without polluting the coderd-facing proto
with fields coderd never consumes.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Zach