Deployment Monitor Operator

Proactive Observability for Kubernetes Deployments: An Operator for Change Notifications

This Kubernetes Operator provides an automated, proactive monitoring solution for Deployment resources across all namespaces. It dramatically improves cluster observability by detecting specific changes and notifying stakeholders—a critical capability for maintaining operational integrity and reacting instantly to infrastructure events.

Key Features and Technical Highlights

1. Declarative Monitoring via CRD – Users define monitoring rules (target annotations/labels and recipient email addresses) through a custom DeploymentMonitor resource, leveraging Kubernetes’ native extensibility for clear, version‑controlled configuration.
2. Cluster‑wide Change Detection – The operator continuously watches every Deployment. When a change in the spec or status of a monitored deployment is detected, it is immediately flagged.
3. Secure Email Notification – Upon detecting a relevant change, the operator sends an email alert to predefined recipients. SMTP credentials are securely stored in Kubernetes Secrets, preserving credential confidentiality.
4. Built with Kubebuilder – Developed using Kubebuilder, the operator follows standard Kubernetes best practices, delivering a robust, extensible, and maintainable monitoring solution.

Operational Flow

• Configuration – A DeploymentMonitor CR specifies which Deployments to watch and where to send notifications, referencing a securely stored SMTP configuration in a Kubernetes Secret.
• Continuous Reconciliation – The operator’s controller constantly reconciles DeploymentMonitor objects with the actual state of Deployments throughout the cluster.
• Alerting – Any deviation that matches the criteria defined in a DeploymentMonitor triggers a formatted email notification.

Deployment & Usage (Key Steps)

• Prerequisites – Standard Kubernetes tools (kubectl, Docker), a Go runtime, and an accessible image registry.
• Deploy – Build and push the operator’s Docker image, then apply the deployment manifest to your cluster.
• Configure – Create a Kubernetes Secret containing your SMTP credentials and define DeploymentMonitor CRs for the deployments you wish to monitor.
• Validate – Create or modify a Deployment that matches a monitor’s criteria and observe the generated email alerts and operator logs.

This project demonstrates deep expertise in building Kubernetes Operators, defining custom resources, securely handling secrets, and delivering robust, automated solutions for cloud‑native environments.