CAST AI Webhooks & Events
Overview
CAST AI emits events for node lifecycle changes, autoscaler decisions, and security findings. Configure webhook endpoints or use the audit log API to track all cluster operations. Integrates with Slack, PagerDuty, and custom HTTP endpoints.
Prerequisites
- CAST AI cluster connected and active
- HTTPS endpoint for receiving webhooks (or Slack webhook URL)
- API key with Full Access
Instructions
Step 1: Configure Notification Channels in Console
Navigate to console.cast.ai > your cluster > Notifications. Available channels:
- Slack: Webhook URL integration
- Email: Per-user notifications
- PagerDuty: Incident escalation
- Custom webhook: Any HTTPS endpoint
Step 2: Query Audit Log via API
curl -s -H "X-API-Key: ${CASTAI_API_KEY}" \
"https://api.cast.ai/v1/kubernetes/clusters/${CASTAI_CLUSTER_ID}/audit-log?limit=20" \
| jq '.items[] | {
time: .createdAt,
action: .action,
initiator: .initiatedBy,
details: .details
}'
Step 3: Build a Custom Notification Handler
import express from "express";
const app = express();
app.use(express.json());
interface CastAIEvent {
eventType: string;
clusterId: string;
clusterName: string;
timestamp: string;
data: {
nodeName?: string;
instanceType?: string;
lifecycle?: string;
action?: string;
savingsImpact?: number;
};
}
app.post("/castai/events", async (req, res) => {
const event: CastAIEvent = req.body;
switch (event.eventType) {
case "node.added":
console.log(
`Node added: ${event.data.nodeName} (${event.data.instanceType}, ${event.data.lifecycle})`
);
await notifySlack(
`New ${event.data.lifecycle} node: ${event.data.instanceType}`
);
break;
case "node.removed":
console.log(`Node removed: ${event.data.nodeName}`);
break;
case "node.spot_interrupted":
console.log(`Spot interruption: ${event.data.nodeName}`);
await notifyPagerDuty("Spot instance interrupted", event);
break;
case "savings.threshold":
console.log(`Savings threshold crossed: ${event.data.savingsImpact}%`);
break;
default:
console.log(`Unhandled event: ${event.eventType}`);
}
res.status(200).json({ received: true });
});
async function notifySlack(message: string): Promise<void> {
await fetch(process.env.SLACK_WEBHOOK_URL!, {
method: "POST",
headers: { "Content-Type": "application/json" },
body: JSON.stringify({
text: `:kubernetes: CAST AI: ${message}`,
}),
});
}
app.listen(3000, () => console.log("CAST AI webhook handler on :3000"));
Step 4: Kubernetes-Native Event Monitoring
kubectl get events -n castai-agent --watch \
--field-selector=source=castai
apiVersion: batch/v1
kind: CronJob
metadata:
name: castai-daily-summary
spec:
schedule: "0 9 * * *"
jobTemplate:
spec:
template:
spec:
containers:
- name: summary
image: curlimages/curl
command:
- sh
- -c
- |
SAVINGS=$(curl -s -H "X-API-Key: ${CASTAI_API_KEY}" \
"https://api.cast.ai/v1/kubernetes/clusters/${CLUSTER_ID}/savings")
curl -X POST ${SLACK_WEBHOOK_URL} \
-H "Content-Type: application/json" \
-d "{\"text\": \"Daily CAST AI savings: $(echo $SAVINGS | jq -r '.monthlySavings') USD/month\"}"
restartPolicy: Never
Error Handling
| Issue | Cause | Solution |
|---|
| Webhook not firing | Wrong URL in console | Verify endpoint is reachable |
| Slack message empty | Payload format changed | Check current event schema |
| Duplicate events | No idempotency | Track event IDs in your handler |
| Events delayed | Queue backlog | Monitor CAST AI status page |
Resources
Next Steps
For performance optimization, see castai-performance-tuning.
