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Kubernetes CronJobs in 60 Seconds

Monitor Kubernetes CronJobs with zero code changes using our Helm chart and sidecar pattern.

Prerequisites​

  • kubectl configured with cluster access
  • Helm 3.x installed
  • Permissions to create CronJobs and RBAC resources
  • A Saturn organization token (get one from dashboard)
Organization Tokens

Create an org-wide token in Settings → Tokens to avoid per-monitor setup. The sidecar will auto-register new monitors.

Installation​

1. Add Helm Repository​

helm repo add saturn https://charts.saturnmonitor.com
helm repo update

2. Install with Helm​

Replace YOUR_ORG_TOKEN with your actual token:

helm install nightly-backup saturn/saturn-monitor \
  --set saturn.token=YOUR_ORG_TOKEN \
  --set cronjob.schedule="0 3 * * *" \
  --set cronjob.container.image="your-backup-image:latest" \
  --set cronjob.container.command='["/bin/sh"]' \
  --set cronjob.container.args='["-c", "./backup.sh"]'

3. Validate Deployment​

Check that the CronJob was created:

kubectl get cronjob nightly-backup

Expected output:

NAME             SCHEDULE      SUSPEND   ACTIVE   LAST SCHEDULE   AGE
nightly-backup   0 3 * * *     False     0        <none>          30s

How It Works​

The Helm chart deploys a CronJob with two containers:

The Saturn sidecar:

  1. Sends a start ping when the pod begins
  2. Waits for the main container to complete
  3. Sends success/fail ping with duration and exit code
  4. Captures stdout/stderr if enabled

Configuration Options​

Basic Example with Output Capture​

values.yaml
saturn:
  token: "YOUR_ORG_TOKEN"
  apiUrl: "https://api.saturnmonitor.com"  # Optional: use self-hosted
  captureOutput: true
  maxOutputBytes: 10240  # 10KB limit

cronjob:
  name: my-backup
  schedule: "0 3 * * *"
  timezone: "America/New_York"  # Optional
  
  container:
    name: backup
    image: backup-tool:v1.2
    command: ["/bin/bash"]
    args: ["-c", "./run-backup.sh"]
    
    resources:
      limits:
        cpu: "1000m"
        memory: "1Gi"
      requests:
        cpu: "200m"
        memory: "256Mi"

  # Job retry configuration
  backoffLimit: 2
  restartPolicy: OnFailure

Install with custom values:

helm install my-backup saturn/saturn-monitor -f values.yaml

Advanced: Multiple CronJobs​

To monitor multiple jobs, install the chart multiple times:

# Backup job
helm install backup saturn/saturn-monitor \
  --set saturn.token=YOUR_ORG_TOKEN \
  --set cronjob.schedule="0 3 * * *" \
  --set cronjob.container.image="backup:latest"

# Cleanup job
helm install cleanup saturn/saturn-monitor \
  --set saturn.token=YOUR_ORG_TOKEN \
  --set cronjob.schedule="0 4 * * *" \
  --set cronjob.container.image="cleanup:latest"

Verify First Ping​

After the job runs (or trigger manually), check the Saturn dashboard:

# Trigger a manual run for testing
kubectl create job test-run-1 --from=cronjob/nightly-backup

Within seconds, you should see:

  • New monitor appears in dashboard
  • First ping recorded
  • Duration tracked
Manual testing

Use kubectl create job --from=cronjob/... to test immediately without waiting for the schedule.

Connect Alerts​

Add Slack/Discord/Email alerts:

  1. Go to Settings → Integrations
  2. Connect your preferred channel
  3. Configure routing rules
  4. Test with a manual failure

Common Issues​

imagePullBackOff​

Problem: Sidecar image can't be pulled

Solution: Check image registry access and pull secrets:

kubectl describe pod <pod-name>

Timezone Not Working​

Problem: Schedule runs at wrong time

Solution: Verify timezone support in your cluster (requires Kubernetes 1.25+):

kubectl version --short

For older clusters, use UTC and adjust schedule accordingly.

Sidecar Not Reporting​

Problem: Job runs but no pings appear

Solution: Check sidecar logs:

kubectl logs <pod-name> -c saturn-sidecar

Common causes:

  • Invalid token
  • Network policy blocking egress
  • API endpoint unreachable

Resource Recommendations​

Job DurationSidecar CPUSidecar Memory
< 5 min50m64Mi
5-30 min100m128Mi
> 30 min200m256Mi

Next Steps​

You should now see your first healthy monitor within 10 minutes.

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