Focused on sharing DevOps, Kubernetes, Linux, Docker, Istio, microservices, Spring Cloud, Python, Go, databases, Nginx, Tomcat, cloud computing, and related technologies.
This guide explains how to set up NVIDIA drivers, install the NVIDIA device plugin, and create a Kubernetes pod that requests GPU resources, providing step‑by‑step commands and a sample YAML manifest for GPU‑enabled workloads.
This guide explains why a Calico pod shows "BIRD is not ready: BGP not established" in a Kubernetes cluster, identifies the missing node interface detection as the root cause, and provides step‑by‑step instructions to adjust the IP autodetection method and restore pod health.
This guide shows how to check certificate expiration in a Kubernetes cluster, renew all certificates using kubeadm, and verify the renewal, helping you resolve the “certificate has expired or is not yet valid” error.
This guide explains how to set up SSH keys on Jenkins and a GitLab repository so Jenkins can securely pull code, detailing the required public‑key addition to the repo, private‑key credential configuration in Jenkins, and a test job to verify the pull.
The article explains the “Too many open files” error in Kubernetes, clarifies that it refers to exceeding system file‑handle limits, shows how to inspect current usage with ulimit and lsof, and provides step‑by‑step commands to temporarily or permanently raise the limits and troubleshoot the application code.
This guide explains how to push a Kubernetes cluster toward its theoretical limit of 5,000 nodes by detailing official limits, master node sizing for GCE and AWS, kube‑apiserver high‑availability and connection‑count tuning, scheduler and controller‑manager leader election settings, kubelet optimizations, and DNS anti‑affinity configuration.
This guide walks through ten frequent Kubernetes problems—from service access failures and port‑mapping errors to image pull issues and CrashLoopBackOff—explaining root causes, showing exact error messages, and providing concise command‑line solutions to restore cluster health.
GitOps, a cloud‑native continuous deployment approach that uses Git as the single source of truth, enables secure, auditable, and multi‑tenant Kubernetes management by automating state reconciliation, supporting multi‑cluster and multi‑environment deployments, and integrating tools like Argo CD, Flux, Helm, and Kustomize.
This tutorial walks through migrating a two‑node Kubernetes cluster (master and worker) from Docker to containerd on CentOS 7, covering environment setup, node draining, Docker removal, containerd installation and configuration, kubelet adjustments, uncordoning, and verification of the new container runtime.
Ephemeral containers are temporary debugging pods in Kubernetes that lack resource guarantees and cannot restart automatically; this guide explains their differences, enabling the feature via kube-apiserver and kubelet flags, creating a sample Tomcat pod, adding an Ephemeral container with kubectl debug, and updating it using raw API calls.
