Infrastructure
Content
Node maintenance activities required for a Kubernetes cluster:
Node Health Monitoring
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System Resources: Monitor CPU, memory, disk space, and network utilization
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Kubelet Status: Ensure kubelet service is running and responsive
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Container Runtime: Monitor Docker/CRI-O/containerd health and performance
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Node Conditions: Track Ready, MemoryPressure, DiskPressure, and PIDPressure status
Operating System Maintenance
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Security Patches: Apply OS security updates using rolling update strategy
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Kernel Updates: Coordinate kernel updates with node cordoning and draining
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Package Management: Maintain system packages and dependencies
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Log Rotation: Configure system log rotation to prevent disk space issues
Storage Management
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Disk Space: Monitor filesystem usage for root, container images, and logs
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Volume Health: Check persistent volume health and storage driver status
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Image Cleanup: Remove unused container images and implement garbage collection
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Temporary Files: Clean up temporary files and container debris
Network Configuration
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Network Connectivity: Verify pod-to-pod and external network connectivity
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CNI Health: Monitor Container Network Interface plugin status
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DNS Resolution: Ensure proper DNS resolution within the cluster
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Firewall Rules: Maintain appropriate firewall and security group configurations
Node Lifecycle Operations
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Cordoning: Safely cordon nodes before maintenance to prevent new pods
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Draining: Gracefully drain pods before node maintenance or replacement
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Scaling: Add or remove nodes based on capacity requirements
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Replacement: Replace unhealthy or aging nodes with minimal disruption
Security Hardening
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Certificate Rotation: Rotate kubelet and node certificates before expiration
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User Access: Manage SSH access and disable unnecessary services
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Compliance: Ensure nodes meet security compliance requirements (CIS benchmarks)
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Vulnerability Scanning: Regular security scans and remediation