New mTLS-protected routes on the agent:
- POST /topology/apply — master pushes {hydrated, version_hash}.
Validates the hash matches locally (serialisation drift guard),
runs the topology through the same validator/composer pipeline
used master-side, then creates bridges + compose up + records the
apply in topology.db.
- POST /topology/teardown — dismantles compose, removes bridges,
clears topology.db. Idempotent.
- GET /topology/state — returns applied row + live docker
observation for the heartbeat.
Implementation lives in decnet/agent/topology_ops.py; it reuses the
private compose helpers from decnet.engine.deployer so we don't
duplicate compose/project-name plumbing. The apply path is sync
under the hood (docker SDK + subprocess); we hop to a thread so the
event loop keeps servicing other agent traffic.
v1 is one-topology-per-agent; cross-topology apply returns 409.
Step 4 of the agent <-> topology integration.
Single-row sqlite tracking which topology the agent last applied and
its version hash. Sync/stdlib, same pattern as the log-forwarder
offset store. v1 is one-topology-per-agent; attempting to apply a
different topology over a populated row raises AlreadyApplied so the
endpoint can return 409. observed() snapshots live docker state
(decnet-topology-* bridges + decnet-* containers) for the heartbeat.
The store is a cache, not authority — no auto-restore on boot.
Master remains the only source of truth.
Step 3 of the agent <-> topology integration.
