Introduces internal/harness — a minimal Harness interface inspired by
GoogleCloudPlatform/scion — plus four backends (k8sjob, subprocess,
webhook, stub) and an OTel-traced Registry that spans every dispatch
and injects W3C trace context into child processes via env vars.
Phases landed together on this branch:
1. internal/harness scaffold: Harness/Capabilities/ExecRequest/
ExecResult/Budget/Usage types, Registry with Resolve/Execute,
in-memory stub backend.
2. internal/harness/k8sjob: wraps existing k8s.JobRunner behind the
Harness interface with a Waiter abstraction (real clientset +
test fake). BuildHandler exports the per-agent config logic.
3. internal/harness/subprocess: os/exec-based backend (Mac+Linux),
per-run workdir, result.json handoff, bounded log capture,
Budget-driven wall-clock timeout.
4. internal/harness/webhook: synchronous HTTP POST with HMAC
signing via internal/webhooks.ComputeHMACSignature, per-agent
URL/secret/timeout read from harness_config_json.
5. internal/observability: OTel tracer init via OTLP HTTP (opt-in
via SYNAPBUS_OTEL_ENABLED), W3C propagator always installed;
Registry.Execute starts a harness.execute span per dispatch and
calls InjectTraceContext into req.Env so children inherit it.
6. internal/harness/runs: SQLite-backed Observer that persists a
harness_runs row per dispatch with status, usage, cost, duration,
trace_id, session_id, and a bounded logs excerpt.
Schema: new migration 019_harness.sql adds agents.harness_name /
local_command / harness_config_json columns and the backend-agnostic
harness_runs table with indices on (agent, created_at), (status),
(trace_id), (run_id). internal/reactor/reactor_test.go inline schema
updated to match.
Deployment: deploy/kubic/otel-collector.yaml stands up an otel-collector
Deployment + ConfigMap + ClusterIP Service in the synapbus namespace on
kubic, receiving OTLP gRPC (4317) and HTTP (4318) and exporting debug
output until a Tempo/Jaeger backend lands.
Docs: docs/harness-otel-research.html compares scion and paperclip
side-by-side and maps the current synapbus executor surface; its
companion docs/harness-otel-design.md carries the phase plan, span
taxonomy, and migration schema verbatim.
The reactor currently still calls k8s.JobRunner directly — rewiring it
through the Registry is a follow-up, intentionally out of scope for
this branch to keep the refactor reversible. The new packages are
independently tested (~78 new tests across 7 packages) and the full
project test suite passes.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
