| `PLATFORM_URL` | `http://localhost:8080` | Platform API URL. Inside a Docker container, use `http://host.docker.internal:8080` to reach the platform on the host machine. |
| `WORKSPACE_ID` | — | Workspace ID from Step 1 (required; no default) |
| `PORT` | `8000` | Agent server port. Must match `containerPort` in Kubernetes and the port mapped with `-p` in Docker. |
| `MOLECULE_API_URL` | `http://localhost:8080` | Platform API URL. From Docker on Linux/macOS, use `http://host.docker.internal:8080` to reach the host machine. |
When the container receives SIGTERM (e.g. from `docker stop` or Kubernetes pod deletion), the workspace's uvicorn server initiates graceful shutdown: the heartbeat loop stops, active A2A tasks are given a grace period to complete, and any snapshotable state is persisted before the process exits.
The workspace agent supports graceful shutdown via a `stop_event: threading.Event`. When the container receives SIGTERM (e.g. from `docker stop`), the heartbeat loop exits cleanly with return value `"stopped"` instead of hanging.
To integrate the heartbeat loop into custom agent code:
To enable SIGTERM handling in your agent code:
```python
importasyncio
importos,signal
fromheartbeatimportHeartbeatLoop
importsignal,threading
frommolecule_agentimportRemoteAgentClient
# SIGTERM is handled by the Docker runtime, which sends the signal to the
# workspace process. The workspace (via uvicorn) initiates graceful shutdown:
# the heartbeat loop is stopped, any active adapter tasks are cancelled, and
# in-flight A2A requests are given a grace period to complete.
#
# For custom integration with the heartbeat loop directly:
The Docker `stop` command sends SIGTERM and waits up to 10 seconds by default before sending SIGKILL. The healthcheck ensures orchestrators detect an unhealthy container before the SIGTERM timeout.
Without explicit SIGTERM handling, the container will be killed after the Docker default 10-second timeout. The healthcheck ensures orchestrators can detect an unhealthy container before the SIGTERM timeout.
## Kubernetes deployment
@@ -169,7 +172,7 @@ ports:
containerPort:8000
livenessProbe:
httpGet:
path:/.well-known/agent-card.json
path:/agent/card
port:http
initialDelaySeconds:30
periodSeconds:30
@@ -177,7 +180,7 @@ livenessProbe:
failureThreshold:3
readinessProbe:
httpGet:
path:/.well-known/agent-card.json
path:/agent/card
port:http
initialDelaySeconds:10
periodSeconds:10
@@ -186,13 +189,13 @@ readinessProbe:
terminationGracePeriodSeconds:120
```
> **Note:** The Kubernetes `terminationGracePeriodSeconds` should exceed the liveness probe failure threshold so that the probe can register a failure before the pod is killed. With `periodSeconds: 30` and `failureThreshold: 3`, the probe does not register a failure until approximately 120–150s after the container becomes unhealthy. Set `terminationGracePeriodSeconds: 120` or higher.
> **Note:** `terminationGracePeriodSeconds` must exceed the liveness probe failure window (3 × 30s = 90s) so that Kubernetes sends SIGTERM and allows graceful shutdown before the pod is killed. The 120s value here gives a 30s buffer beyond the 90s threshold.
## Troubleshooting
| Symptom | Cause | Fix |
|---|---|---|
| Container shows `unhealthy` after startup | Platform unreachable from container | Verify `PLATFORM_URL` uses `host.docker.internal` (Docker) or the correct host IP |
| Container shows `unhealthy` after startup | Platform unreachable from container | Verify `MOLECULE_API_URL` uses `host.docker.internal` (Docker) or the correct host IP |
| `curl: (7) Failed to connect` on healthcheck | Container not fully started | Wait up to 30s; increase `start_period` |
| Agent not appearing on canvas | Wrong `WORKSPACE_ID` or expired token | Re-run registration; check platform logs |
| `host.docker.internal` not resolved | Linux host without the Docker flag | Use `--add-host=host.docker.internal:host-gateway` or the host's LAN IP |
Reference in New Issue
Block a user
Blocking a user prevents them from interacting with repositories, such as opening or commenting on pull requests or issues. Learn more about blocking a user.