Troubleshooting

Enables kubelet TLS bootstrapping so the controller-manager issues proper serving certificates, resolving the x509 certificate validation error in metrics-server. Covers deployment edits, controller-manager configuration, and automated certificate renewal.

Learn how to insert iptables rules at a specific position using the -I flag, with syntax breakdown and a practical SSH example.

A practical cheat sheet for managing firewalld on RHEL, Fedora, and CentOS systems. Covers zones, services, ports, rich rules, NAT, and direct iptables-style rules.

A guide to the ip link show type and ip address show type commands in Linux for filtering network interfaces by type. Covers physical, virtual, and tunneling interface types with practical examples.

A deep dive into how Kubernetes DNS resolves service names to IP addresses, covering A records, SRV records, search domains, and the full lookup path from pod to CoreDNS. Understanding this lifecycle is essential for debugging connectivity issues and designing resilient microservice architectures.

When a Java process is eating your CPU, you need to know exactly which thread is responsible. This guide walks through JVisualVM, jstack, top, and jvmtop to pinpoint the culprit.