Linkerd - Service Mesh Overview
Linkerd is a lightweight, open-source service mesh for Kubernetes that provides runtime debugging, observability, reliability, and security for mic...
Istio - Service Mesh Overview
Istio is an open-source service mesh that helps manage service-to-service communication within a Kubernetes cluster (and beyond).
Docker Orchestration
What it is: A tool for defining and running multi-container Docker applications using a YAML file to configure application services, networks, and ...
Docker Commands & Troubleshooting
Category: DevOps Tags: docker, commands, troubleshooting, debugging, best-practices What Docker CLI provides: The primary interface for managing Do...
Docker Fundamentals
What it is: A lightweight, standalone package that includes everything needed to run an application: code, runtime, system tools, libraries, and se...
Docker Networking & Storage
What it is: Docker's networking system that allows containers to communicate with each other and the outside world through various network drivers ...
Service Mesh / Sidecar Pattern
A Service Mesh is a dedicated infrastructure layer for managing service-to-service communication in microservices.
Hexagonal Architecture (Ports & Adapters)
Hexagonal Architecture, or Ports and Adapters, separates the core logic from the infrastructure, allowing independent evolution of business logic a...
Domain-Driven Design (DDD)
Domain-Driven Design (DDD) is an approach to software development that focuses on modeling software based on the business domain, using rich, behav...
Layered Architecture
Layered Architecture (also known as n-tier) divides the system into layers with well-defined responsibilities, such as presentation, business, and ...
Monolithic Architecture
A Monolithic Architecture is a single-tiered application structure where all functions—UI, business logic, and data access—are tightly coupled and ...
Microservices Architecture
A Microservices Architecture is a design where an application is composed of small, independent services that communicate over well-defined APIs.
CQRS (Command Query Responsibility Segregation)
CQRS separates the responsibility for reading and writing data into different models, enhancing scalability and performance for complex systems.
Event-Driven Architecture
Event-Driven Architecture (EDA) is a design paradigm where components communicate through events—emitted, consumed, and reacted upon—decoupling the...
Serverless Architecture
Serverless Architecture delegates infrastructure management to the cloud, allowing you to write functions that execute on demand without managing s...
Kubernetes Networking
What it is: Stable network endpoint that provides access to a set of pods, with built-in load balancing and service discovery.
CKA Guide: Kubernetes Security - RBAC, ServiceAccounts, SecurityContext & NetworkPolicies
Kubernetes Security Layers: The Principle of Least Privilege: Authentication, Authorization, and Admission Control: RBAC Component Model: RBAC Perm...
CKAD Essential kubectl Commands Study Guide
The foundation of CKAD exam success lies in mastering pod creation, configuration management, and basic troubleshooting.
Kubernetes Security: Complete Deep Technical Guide
Kubernetes security is built on multiple layers of defense - no single security mechanism protects everything.
CKA Guide: Kubernetes Cluster Components - Control Plane & Worker Node Architecture
From Monolithic to Distributed Control Plane: The Microservices Pattern Applied to Infrastructure: The Control Plane as a Control System: State Con...
Kubernetes Networking: Complete Deep Technical Guide
Kubernetes networking is fundamentally different from traditional server networking.
CKA Study Guide: Kubernetes Cluster Upgrades with kubeadm
Upgrading a Kubernetes cluster is fundamentally different from upgrading a monolithic application.
CKA Guide: ConfigMaps and Secrets - Application Configuration
The Twelve-Factor App Principle: ConfigMaps and Secrets embody the core principle: "Store config in the environment, not in code" The Immutable Inf...
Kubernetes Configuration Management: A Deep Dive
Before diving into Kubernetes-specific solutions, let's understand the core problem.
Multi-Container Pods: Complete Deep Technical Guide
A multi-container pod is a single Kubernetes pod that contains more than one container.
CKA Guide: Pod Lifecycle - Creation, Scheduling, Networking, Storage & Logging
Pod Design Philosophy: Pod as Shared Execution Environment: Pod Phase Progression: Container State Model within Pods: Complete Pod Anatomy: Init Co...
Kubernetes Secrets: Usage and Best Practices
Kubernetes Secrets are used to securely store sensitive information like passwords, tokens, and keys, and expose them to containers at runtime.
CKA Study Guide: RBAC (Role-Based Access Control)
Kubernetes is essentially a distributed state management system where the API server is the single source of truth.
Kubernetes Services and Networking: Deep Dive
1. [The Fundamental Problem: Why Services Exist](#the-fundamental-problem) 2. [Service Types Deep Dive](#service-types) 3. [Ingress Controllers and Ro...
Kubernetes Storage: Complete Deep Technical Guide
Kubernetes storage solves the fundamental problem that containers are ephemeral - when a container restarts, all data inside it is lost.
CKA Study Guide: Manifest Management and Common Templating Tools
As Kubernetes adoption grows, organizations quickly discover that managing raw YAML manifests becomes unwieldy.
Understanding PersistentVolumeClaims (PVC) in Kubernetes
PersistentVolumeClaims (PVCs) are how pods request and use persistent storage in Kubernetes.
Multi-Container Pods: A Deep Dive
Before diving into patterns, it's crucial to understand why Kubernetes allows multiple containers in a single pod when the general recommendation i...
CKAD Exam Tips & Tricks
USE WHEN: Question asks for sidecar, logging, or monitoring containers USE WHEN: Question involves configuration data, properties files, or environ...
Understanding `initContainers` in Kubernetes
are a native Kubernetes feature that allow you to run one or more containers before your main application containers start.
Cluster Components - Comprehensive Study Guide
Understanding cluster components is understanding how Kubernetes actually works - not just what it does: Control Plane = The brain of Kubernetes (d...
Exam Modules
Here are the key modules you should study for the Certified Kubernetes Application Developer (CKAD) exam: Understanding deployment strategies (roll...
CKA Guide: Robust, Self-Healing Application Deployments
Fault Tolerance vs Fault Avoidance: The Resilience Engineering Model: The Failure Domain Hierarchy: Blast Radius Minimization: The Chaos Engineerin...
Kubernetes Observability & Monitoring: Complete Deep Technical Guide
Observability is the ability to understand what's happening inside your Kubernetes cluster and applications by examining their external outputs.
Common Kubernetes Errors
Click to read more...
Kubernetes Configuration & Security
What it is: A Kubernetes object that stores non-confidential configuration data in key-value pairs, allowing you to decouple configuration from app...
CKA Study Guide: Provisioning Infrastructure for Kubernetes
Kubernetes doesn't exist in a vacuum - it's a sophisticated orchestration platform that makes specific assumptions about the underlying infrastruct...
Security - Comprehensive Study Guide
Security in Kubernetes is about controlling access and enforcing boundaries in a shared platform: Identity and Access Management - Who can do what ...
YAML Manifests - Comprehensive Study Guide
YAML manifests are declarative infrastructure definitions - the DNA of your Kubernetes applications: Desired State Declaration - You describe WHAT ...
Kubernetes Annotations – Hidden Power in Metadata
Annotations in Kubernetes are key-value pairs that attach arbitrary, non-identifying metadata to objects.
CKA Guide: Deployments, Rolling Updates & Rollbacks
Declarative vs Imperative Paradigm: At its core, Kubernetes embraces a declarative model where you describe the desired end state, not the steps to...
Pod Lifecycle - Comprehensive Study Guide
Understanding pod lifecycle is understanding how Kubernetes actually runs your applications: Atomic Deployment Unit - Pods are the smallest deploya...
CKA Study Guide: ClusterIP, NodePort, LoadBalancer Service Types and Endpoints
In a world where pods are ephemeral and their IP addresses change constantly, applications need a stable way to communicate with each other.
Kubernetes Cluster Internals: Complete Deep Technical Guide
Understanding Kubernetes cluster internals is crucial for troubleshooting, performance optimization, and designing robust systems.
Kubernetes Glossary – In-Depth Explanations for CKAD & CKA
--- What: A pod is the smallest deployable unit in Kubernetes.
CKA Study Guide: etcd Backup and Restore
etcd is not just another database - it's the single source of truth for your entire Kubernetes cluster.
Kubernetes Workload Controllers: Complete Deep Technical Guide
Kubernetes workload controllers are the "managers" that ensure your applications run correctly.
Shared Pod Microservices vs Sidecar Pattern
This document explains the difference between running multiple microservices in a single pod (with shared volumes) and using the sidecar pattern.
ConfigMap: Inline vs File-Based Configuration
Understanding the difference between defining Kubernetes ConfigMaps inline vs from external files is important for managing application configurati...
CKA Study Guide: Application Scaling in Kubernetes
Application scaling in Kubernetes isn't just about handling more traffic—it's about optimizing resource utilization, cost efficiency, and user expe...
CKA Study Guide: kubeadm Cluster Installation
Before kubeadm, installing Kubernetes was a nightmare of manual configuration, cryptographic complexity, and system administration.
CKA Guide: Kubernetes Backup & Restore - etcd Backup, Disaster Recovery & Cluster Management
Understanding What Needs Protection: The Recovery Time Hierarchy: etcd as the Source of Truth: etcd Cluster Topology: Basic etcd Snapshot Creation:...
Kubernetes Health Probes - Liveness vs Readiness
Kubernetes uses health probes to automatically detect when containers are alive and ready to serve traffic.
CKA Study Guide: Highly-Available Kubernetes Clusters
A basic kubeadm cluster has a critical weakness: if the control plane node fails, the entire cluster becomes unmanageable.
CKAD Commands with Explanations
Click to read more...
State Persistence in Kubernetes: A Deep Dive
State persistence is one of the most critical aspects of running production workloads in Kubernetes.
Core Application Lifecycle Management in Kubernetes: A Deep Dive
Before diving into deployment strategies, it's crucial to understand why Kubernetes was created.
Kubernetes Workloads
What it is: A Kubernetes resource that manages a set of identical pods, providing declarative updates and rollback capabilities for stateless appli...
Kubernetes Commands & Troubleshooting
What kubectl is: The command-line tool for interacting with Kubernetes clusters, providing a way to deploy applications, inspect and manage cluster...
CKA Guide: Kubernetes Troubleshooting - Systematic Debugging and Problem Resolution
The Scientific Method Applied to Debugging: The Debugging Information Hierarchy: The Dependency Stack: The Five Whys Debugging Framework: API Serve...
Kubernetes Configuration Management: Complete Deep Technical Guide
Configuration management in Kubernetes is about separating application code from configuration data.
Kubernetes Storage
What it is: A directory accessible to containers in a pod, providing storage that can persist beyond individual container lifecycles and be shared ...
Backup/Restore - Comprehensive Study Guide
Understanding backup/restore is understanding cluster data protection and disaster recovery: etcd Contains Everything - All cluster state, configur...
Logging Architecture with Sidecar and Elasticsearch
This setup demonstrates how to use a sidecar pattern to collect logs from an application container and forward them to Elasticsearch.
CKA Guide: Application Scaling - Manual and Automatic
The Scalability Triangle: Horizontal vs Vertical Scaling Mental Models: Kubernetes Philosophy: Embrace Horizontal Scaling Kubernetes is designed ar...
Deep Dive: Observability in Container Orchestration
Observability is the ability to understand the internal state of a system by examining its external outputs.
CKA Guide: Ingress Controllers, CoreDNS, and Advanced Networking
The Problem Ingress Solves: The Layer 7 Advantage: The Three-Layer Ingress Model: Ingress Traffic Flow: NGINX Ingress Controller: Traefik Ingress C...
Kubernetes Volumes: Mounting ConfigMaps and Secrets
Volumes in Kubernetes are used to mount external data (config files, secrets, storage) into pods.
Pod Design Deep Dive: Labels, Selectors, Annotations & Networking
Labels are key-value pairs attached to Kubernetes objects (pods, services, deployments, etc.
Kubernetes Services: Deep Technical Explanations with Istio and Helm
Kubernetes Services provide stable network endpoints for accessing pods.
CKA Guide: kubectl Commands & YAML Manifests - Practical Skills Mastery
kubectl as the Universal API Client: The Declarative vs Imperative Paradigm: kubectl Command Anatomy: Resource Naming Conventions: Core CRUD Operat...
CKAD Commands
Click to read more...
kubectl Commands - Comprehensive Study Guide
kubectl is your primary interface to the Kubernetes API server.
Kubernetes Core Concepts
What it is: The smallest deployable unit in Kubernetes, containing one or more containers that share storage and network resources.
CKAD Essential Tips & Commands
HTTP: 80 HTTPS: 443 SSH: 22 Common app ports: 8080, 3000, 5000 CPU: 1000m = 1 core Memory: 1Gi = 1024Mi Always (default for Deployments) OnFailure ...
Monitoring and Debugging: The System's Nervous System
Imagine driving a car with no dashboard - no speedometer, no fuel gauge, no engine temperature warning, no check engine light.
Monitoring and Debugging: The System's Nervous System
Monitoring isn't just about knowing when things break—it's about understanding trends, predicting problems, and optimizing performance.
PowerShell to Unix Command Reference Guide
| PowerShell Cmdlet | Aliases | Unix Equivalent | Description | |-------------------|---------|-----------------|-------------| | | , , | | List fi...
Linux Networking Commands Guide
Category: Networking & System Administration Tags: linux, networking, tcp-ip, dns, routing, firewall, diagnostics What this guide covers: Comprehen...
Linux Troubleshooting Guide
Category: System Administration & Troubleshooting Tags: linux, troubleshooting, debugging, system-recovery, performance, diagnostics What this guid...
Linux System Administration Commands Guide
Category: System Administration & DevOps Tags: linux, system-admin, process-management, file-operations, user-management, monitoring What this guid...
Penetration Testing - Web Application Testing Guide
Category: Penetration Testing - Phase 2 Tags: oscp, htb, web-application, sql-injection, xss, burpsuite, owasp, file-upload What this phase covers:...
Penetration Testing - Exploitation Frameworks & Manual Exploits Guide
Category: Penetration Testing - Phase 3 Tags: oscp, htb, metasploit, exploitation, payloads, manual-exploits, buffer-overflow What this phase cover...
Penetration Testing - Reconnaissance & Enumeration Guide
Category: Penetration Testing - Phase 1 Tags: oscp, htb, reconnaissance, enumeration, nmap, discovery, information-gathering What this phase covers...
Penetration Testing - Post-Exploitation & Privilege Escalation Guide
Category: Penetration Testing - Phase 4 Tags: oscp, htb, privilege-escalation, post-exploitation, linux-privesc, windows-privesc, persistence What ...
Penetration Testing - Reverse Shells & Payload Generation Guide
Category: Penetration Testing - Phase 7 Tags: oscp, htb, reverse-shells, payloads, msfvenom, shell-stabilization, persistence, evasion What this ph...
Penetration Testing - Active Directory Attacks Guide
Category: Penetration Testing - Phase 5 Tags: oscp, htb, active-directory, kerberoasting, bloodhound, golden-ticket, lateral-movement, domain-domin...
Penetration Testing - Network Pivoting & Lateral Movement Guide
Category: Penetration Testing - Phase 6 Tags: oscp, htb, pivoting, lateral-movement, tunneling, proxychains, port-forwarding, chisel What this phas...
Methodologies & Practices Glossary
What it is: Set of principles and practices for software development that emphasizes collaboration, flexibility, and rapid iteration.
Performance & Optimization Glossary
What it is: Temporary storage that saves frequently accessed data for faster retrieval.
Development Terms Glossary
What it is: A set of rules and protocols that allows different software applications to communicate with each other.
Security Glossary
What it is: Process of verifying the identity of a user, device, or system trying to access a resource.
Infrastructure & Networking Glossary
What it is: A computer or software program that provides services, data, or resources to other computers (clients) over a network.
CloudWatch vs CloudTrail - AWS Services Comparison
CloudWatch and CloudTrail are two completely separate AWS services that serve different purposes but can integrate together.
Helm: ConfigMaps and Secrets in Charts
Helm templates allow you to inject config and secrets using values files and inline templates.
Marketing & Sales Vocabulary Guide
Modern marketing approaches leveraging digital channels and data.
Business Strategy & Operations Vocabulary Guide
Core frameworks and concepts for business strategy development.
Generic Corporate Vocabulary Guide
Essential vocabulary for understanding organizational hierarchy and management concepts.
Finance & Accounting Vocabulary Guide
Core documents and concepts for understanding company financial health.
IT & Software Development Vocabulary Guide
Understanding the complete process of software creation and maintenance.
Docker Best Practices
Create non-root user in Dockerfile Use USER directive Set proper file permissions Avoid 'latest' tag in production Pin to specific versions Use dig...
12-Factor App Methodology Compliance
The Twelve-Factor App methodology is a set of best practices for building software-as-a-service applications that are portable, scalable, and maint...
Java Spring Boot - Microservices Patterns
Prevents cascading failures in distributed systems States: Closed, Open, Half-Open Implementation: Use Hystrix or Resilience4j Configuration: Failu...
CompTIA Security+ - Network Security
ESP (Encapsulating Security Payload) - provides confidentiality AH (Authentication Header) - provides integrity Tunnel mode - entire IP packet encr...
Kubernetes Networking Deep Dive
Each pod gets its own IP address Pods can communicate directly without NAT CNI plugins handle network implementation Flat network space across all ...
CompTIA Security+ - Cryptography
AES - Advanced Encryption Standard DES - Data Encryption Standard (deprecated) RSA - Most common public key algorithm ECC - Elliptic Curve Cryptogr...
Laboratory Abbreviations Reference Guide
Essential department abbreviations used across all laboratory information systems.