io.github.karandaid/karandeepsingh-blog

Search Karandeep Singh's blog (DevOps/AWS articles and cheatsheets). Returns ranked cards with title, URL, tags, date, reading time, and summary.

Read a post's full text by URL, paginated. Returns a window of characters; call again with the returned next offset to continue.

List the most recently published posts.

List posts with a given tag (e.g. aws, lambda, cost, aurora). Use list_topics to see all tags.

List every tag on the blog with a post count, for discovering what's covered.

Given a post URL, find other posts that share the most tags with it.

Return a random post from the blog — a surprise pick.

Jump straight to a cheatsheet by topic (docker, cloudformation, cost, aurora, kubernetes, …) and get its full text.

List all cheatsheets (quick-reference guides) on the blog.

Test the user's knowledge with real multiple-choice questions written for the blog's articles. Returns questions, options, and an answers section with explanations. Ask the questions first, then revea…

Return just the runnable commands and code blocks from the best-matching article or cheatsheet — no prose. Use when the user wants the command, not the explanation.

My Atuin notes. Search keybindings, filter and search modes, the search flags worth knowing, sync and account commands, stats, config essentials, and troubleshooting — checked against Atuin 18.19.0.

Quick-reference for a lean, low-cost cloud stack. Free-tier frontend hosting, API platforms, serverless Postgres, auth, a full cost comparison table, low-cost VPS/cloud providers (OVH, Hetzner, Oracle…

A practical Go reference for DevOps work covering go mod and build commands, core syntax, concurrency patterns, testing, and the stdlib snippets I reuse most.

My tmux notes. Session management, window and pane keybindings, copy mode, config essentials, and scripting layouts with send-keys.

Quick-reference Jenkins pipeline syntax. Declarative skeletons, credentials binding, parallel stages, shared libraries, triggers, and troubleshooting fixes.

Notes on core Python syntax, error handling, file I/O with pathlib, plus the CLI side (venv, pip, argparse, and python -m tricks).

A dense, practical Docker reference covering the image lifecycle, container run flags, Dockerfiles with multi-stage builds, compose, and cleanup commands.

A dense quick-reference for Bash 5.x scripting. Quoting, parameter expansion, test operators, loops, functions, arrays, traps, and here-docs.

Quick-reference comparing Amazon MSK (managed Kafka) and Kinesis Data Streams, pricing models and idle cost, a feature table, and a clear when-to-choose-which decision guide.

Quick-reference CloudFormation guide. Template sections, intrinsic functions, stack lifecycle CLI commands, change sets, drift detection, and error fixes.

The Ubuntu server commands I reach for daily. Covers apt/dpkg/snap package management, systemd, ufw, user management, networking, and upgrades.

Python concurrency notes covering threading primitives, queue producer/consumer, concurrent.futures, multiprocessing, asyncio, and when to use which.

A working kubectl reference with core resource YAML skeletons, rollout and scaling commands, debugging workflows, and a table of handy one-liners.

My working reference for sed and awk. Substitution, addresses, capture groups, fields, BEGIN/END blocks, associative arrays, and the one-liners I actually use.

Quick-reference Ansible guide. Inventories, ad-hoc commands, playbooks, module table, loops and conditionals, roles layout, Vault, and Jinja2 templating.

My notes for automating AWS with boto3, covering client/resource setup, S3, EC2, Lambda, DynamoDB, and SSM, plus paginators, waiters, and error handling done right.

The command-line one-liners I use daily. find/xargs, grep, curl, jq, tar, disk and process triage, network checks, ssh/rsync, history tricks, and job control.

Working notes for Amazon Linux 2 on EC2. Covers yum and amazon-linux-extras, SSM access, instance metadata, cloud-init, and security updates.

Ctrl-R only matches one result at a time and forgets which directory you were in. Atuin swaps your shell history for a SQLite database and gives you a real search screen — what it does, why directory …

Most Lambda cost advice repeats folklore. This walks through what AWS actually documents and bills — GB-seconds, the 1,769 MB one-vCPU line, the exact 20% arm64 discount and where it does not apply — …

A walkthrough of building a public MCP server for a static blog — one serverless function, a build-time index, and all three MCP primitives — plus the mistakes that cost me an hour and why it runs for…

How to livestream from your phone to other devices through AWS with Amazon IVS, no server and no code, plus a plain-English explanation of every setting in the create-channel wizard and the real gotch…

A system-designer's walkthrough of running a million users an hour on AWS Lambda, the capacity math, concurrency and cold starts, which language to pick, the database bottleneck that actually breaks f…

Amazon S3 Files lets you mount an S3 bucket as a folder on EC2. This is the honest version, the setup gotchas (versioning, subnet, port 2049, a brutal Ubuntu build), how its latency compares to EBS an…

Most of AWS Lambda is configuration, not code, and the defaults aren't always right. This explains what each setting means, memory, timeout, concurrency, architecture, IAM, VPC, environment variables,…

The EC2 launch wizard's storage step has two very different parts, the root volume and the File systems panel, and beginners mix them up. This explains both in plain words, plus when to reach for each…

How Aurora copy-on-write cloning makes a fast, isolated copy of a cluster in minutes regardless of size, proven hands-on, plus when and why to use one, whether to keep or delete it, the benefits and l…

Turn on the RDS Data API for Aurora PostgreSQL and run SQL over an HTTPS endpoint with no persistent connection and no VPC, shown from both the in-console Query Editor and the AWS CLI, plus when to us…

How Aurora write forwarding lets a read replica take writes and pass them to the writer, done hands-on with local write forwarding on Aurora PostgreSQL, plus the global cross-region variant, the laten…

A hands-on walkthrough of extending an Aurora PostgreSQL cluster to a second AWS Region with Aurora Global Database, including the instance-class upgrade and reboot, why the whole cluster shows Modify…

How to add a read replica (reader) to an Aurora PostgreSQL cluster, understand the writer and reader endpoints, prove the reader is read-only, and send read traffic to it, all from the AWS console.

How to find slow queries in Aurora PostgreSQL the way you actually would, starting in the AWS console with Performance Insights and CloudWatch, then dropping into pg_stat_statements and EXPLAIN to fix…

The hands-on second half, connecting Python to Aurora PostgreSQL and Valkey, implementing the cache-aside pattern, and measuring a real 46 ms database read drop to 0.7 ms from cache.

The reasoning behind every choice when creating an Amazon Aurora PostgreSQL cluster, from provisioned vs serverless to the security-group model, so the settings make sense instead of being guessed.

A start-to-finish walkthrough of running Valkey on AWS ElastiCache, built from a real hands-on session, complete with the security-group mistake, the TLS surprise, and a small health-check script.

How to plan and execute Jenkins upgrades, including large multi-version jumps, safely with in-place, blue-green, and phased strategies.

A hands-on guide that takes a web + Postgres + Redis stack from a single Docker Compose file in local dev, to building images with Docker Bake, to pushing them to Amazon ECR for ECS, Fargate, or EKS.

A practical, zero-to-running guide to AWS EKS with eksctl — install the tools, create a cluster with one command, deploy a workload behind an AWS load balancer, and clean up so you do not get a surpri…

A practical playbook for Kubernetes CrashLoopBackOff — the diagnosis workflow (describe, previous logs, events) plus fixes for the six causes you will actually hit, including OOMKilled, failing livene…

A hands-on introduction to Kubernetes fundamentals — pods, deployments, replicasets, and services — built step by step on a local kind cluster, with the mistakes and fixes that make the concepts stick…

The kubectl commands you actually reach for, grouped by task — inspecting pods, managing deployments and services, reading logs, and debugging — with copy-paste examples and notes on when to use each.

Practical sed recipes for working with production logs — error extraction, time-range filtering, multi-line stack trace handling, anonymization, and pre-pipeline cleanup before grep/awk.

The sed gotchas every DevOps engineer hits — GNU vs BSD differences, in-place editing dangers, escape traps, and the portable patterns that work on Linux, macOS, and Alpine without modification.

A safety-first guide to running sed in automated pipelines — idempotency, exit codes, dry-run flags, in-place backup, and patterns that survive multiple runs without corrupting config files.

A walkthrough of sed multiline editing — pattern space, hold space, N/D/P commands, address ranges — built up step by step with real DevOps examples (stack traces, YAML blocks, SQL).

A practical comparison of sed, awk, and grep with a decision tree, performance notes for large log files, and ten side-by-side examples of the same task in all three tools.

A year-end look at Kubernetes mistakes the industry kept making in 2025. Five things teams overinvested in, underinvested in, or simply got wrong on EKS this year.

An opinionated DevOps stack pick from an engineer with years of production experience. Each layer is a vote, with what I would avoid and why.

Learn tmux one concept at a time — sessions, windows, panes, configuration — then build a Go CLI tool that reads a YAML file and launches your entire dev environment automatically.

Build a log aggregator from scratch in Go. Tail files with inotify, survive log rotation, parse syslog and JSON, fan in from multiple sources, and wire up graceful shutdown.

Learn Terraform with AWS step by step. Start with one S3 bucket, hit real errors, fix them, then build a full VPC + EC2 setup. Each step shows the command, the output, and the mistake.

Nginx log analysis from grep to Go — each step shows the command-line approach first, then builds it in Go. Parse access logs, find slow endpoints, detect error spikes, build a log analysis dashboard.

AWS automation from CLI to Go code. Each step shows the AWS CLI command first, then builds it in Go. List EC2 instances, manage S3, check costs, build an infrastructure report tool.

Config templating from envsubst to Go: each step shows the shell way first, then builds it in Go. Handle missing variables, add conditionals, build a config generator for dev/staging/prod.

Process management from command line to Go code. Each step shows the Linux command first, then builds it in Go. Kill processes, send signals, set resource limits, build a process supervisor with auto-…

Linux access control from command line to Go code. Each step shows the Linux command first, then builds it in Go. Parse sudoers, audit permissions, build a security scanner that flags dangerous config…

Timezone handling from command line to Go code — each step shows the Linux command first, then builds it in Go. Hit the DST parsing trap, fix it, normalize log timestamps, end with a multi-zone clock.

CPU monitoring from command line to Go code — each step shows the Linux command first, then builds it in Go. Hit the jiffies trap, fix it, add colored bars, end with a live dashboard.

Learn Unix commands that actually matter in production: pv for progress bars, xargs for parallel execution, watch for live monitoring, column for readable output. Then build a Go log watcher using the…

Deploy a Go HTTP API behind Nginx. Start with a bare server, hit the port 80 permission trap, proxy through Nginx, lose client IPs, fix header forwarding, add rate limiting, and wire up graceful shutd…

Build your own container runtime in Go from scratch. Start by running a command, then add PID isolation, filesystem isolation, hostname, cgroups, one concept at a time.

Build an SQS message processor in Go step by step. Send messages, hit the visibility timeout trap, add batch operations, and build a production-ready polling loop.

Build a DynamoDB CRUD app in Go step by step. Start raw, hit real pain points, and end up with clean struct-based operations.

Build a practical Go CLI tool for AWS S3. Start with listing buckets, then add uploads, downloads, and concurrent transfers step by step.

Build your first Go Lambda function from scratch. We start simple, hit real errors, fix them, and work our way up to a production-ready API endpoint.

Learn how to manage your entire Jenkins setup through version-controlled YAML files using Jenkins Configuration as Code (JCasC), with practical examples for Kubernetes, security, and shared libraries.

Step-by-step tutorial for deploying Jenkins on Amazon EKS. Learn pods vs deployments and why each matters for your CI/CD setup.

A practical guide to Jenkins version selection, covering JVM compatibility, version evolution, and agent requirements, with links to focused deep-dive guides.

The definitive guide to the Linux ls command. Covers its five-decade history from early Unix to GNU coreutils, core options, task-based examples for real-world scenarios, quirky hidden tricks, and a q…

Unlock advanced Git workflows with Jenkins UserRemoteConfig. Perfect for DevOps engineers managing multi-repository pipelines.

Master Linux task automation with cron, make, and systemd timers. Then build a complete Go task runner with scheduling, retries, and a status dashboard.

Master deployment automation with Linux commands and Go. From SSH and rsync basics to building a complete deploy tool with health checks, rollbacks, and multi-server support.

Thirty sed one-liners for everyday log and config work. Each pattern solves a common problem (extract errors, clean configs, parse timestamps, transform JSON). Organized by use case with input/output …

Learn reliable techniques for finding and replacing text across multiple files using sed, including file selection methods, safety practices, and advanced pattern matching with real-world examples.

Jenkins JVM requirements and the Java 8 to 11 to 17 to 21 to 25 transition timeline, with version-by-version compatibility and tuning notes.

Work through a log-filename processing exercise from scratch. Start with simple basename, encounter the symlink bug that breaks extraction, fix it, then benchmark all four approaches yourself (basenam…

Emergency JSON manipulation patterns using sed when jq is unavailable. For scenarios requiring urgent config changes on a locked-down server with no permission to install tools. Always use jq for JSON…

A complete guide to NGINX logs. Learn how to configure, manage, and analyze access and error logs to optimize your NGINX server's performance and troubleshoot issues effectively.

A practical reference for Linux user management. Create, modify, and delete users; work with groups; set file permissions and special bits; monitor access with who, last, and ps; and apply security be…

The Linux top command is an essential tool for real-time system monitoring, providing a dynamic overview of running processes and their resource consumption. This guide digs deep into the functionalit…

This article provides an in-depth exploration of vmstat, a powerful tool for monitoring virtual memory and system performance. Starting with basic commands and moving through advanced functionalities,…

Master AWS security auditing with CLI commands and Go. From checking IAM users and security groups to building a complete scanner that finds and reports misconfigurations.

Jenkins security evolution, the CVE-2024-23897 CLI vulnerability, and keeping plugins patched to shrink the attack surface.

A worked example of scaling a database from a single Postgres instance to a sharded architecture. Start simple, hit realistic bottlenecks (connection limits, replica lag, query timeouts), and fix each…

Master Docker container logging with Linux commands and a real Go log collector. From docker logs basics to a streaming aggregator that processes multiple containers.

Practical Bash automation patterns for deploying to many servers. Includes retry logic, error handling, parallel execution, and template generation that keep multi-server deploys fast and reliable.

Master the art of Bash code shortening with this full guide offering expert techniques, real-world examples, and practical tips to write cleaner, more efficient scripts without sacrificing readability…

Explore practical strategies to implement reliable error handling in Bash scripts, preventing silent failures and building automation you can truly trust.

A step-by-step build of a URL shortener in Go using only the standard library — raw TCP, HTTP parsing, hash-based short codes, file persistence, 302 redirects with click analytics, and rate limiting. …

Create a scalable video platform using AWS Lambda functions that process uploads directly from S3. This simple approach works beautifully for video platforms and requires minimal management.

Master CI pipeline fundamentals with shell scripts and Go. From running tests and collecting artifacts to building a complete build runner with git integration and parallel stages.

Watch bash skills evolve from echo statements to a production deployment script. Start simple, encounter errors (set -e breaks pipelines, unquoted variables cause word splitting), fix each one, learn …

Learn how to leverage sed's powerful text processing capabilities to efficiently update, remove, and transform data in various configuration file formats like YAML, JSON, TOML, and properties files.

Learn how to implement self-healing mechanisms in your Bash scripts with practical examples that handle common failures and recover automatically.

Master service health monitoring with Linux commands and Go. From curl and /proc basics to building a complete health monitor with HTTP checks, TCP probes, resource monitoring, and alerting.

A practical guide to S3 hosting that walks through moving a WordPress documentation site to S3+CloudFront. Covers caching, cost, security hardening, and CI/CD best practices.

Adding Amazon SQS to your video platform creates a buffer between uploads and processing, dramatically improving scalability and reliability. This approach is ideal for systems with unpredictable traf…

An overview hub for custom Bash string functions used in log processing and everyday scripting, linking to focused guides on trimming and case, search and split, and validation and generation.

Bash string functions for length validation, case conversion, substitution, truncation, counting, splitting, capitalization, ROT13, and field extraction (index, substring, join).

Bash string functions for stripping leading and trailing whitespace (ltrim, rtrim, trim) and reversing strings, with performance comparisons against sed and awk.

Bash functions for random string generation, input sanitization, CSV parsing, password-strength checks, and slug generation, plus a complete production string library to source.

Production guide to building serverless data pipelines with Boto3 and Lambda for processing high-volume daily events through an analytics pipeline. Covers cold starts, concurrent execution limits, err…

A comprehensive guide to roll out your own custom Jenkins AMI, perfect for those who want a hassle-free, tailor-made Continuous Integration environment.

Master Git automation with shell hooks and Go. From pre-commit scripts to a complete webhook server that validates payloads, triggers builds, and reports results.

Master remote server configuration with SSH and Go. From bash loops to a complete config tool with parallel execution, idempotent operations, and service verification.

Build custom AMIs using EC2 Image Builder with Amazon Linux 2023 and NGINX.

EC2 Image Builder uses image recipes to define the base image and components that make up your custom AMI. When you need to update packages, add new components, or change the base image, you create a …

Step-by-step guide to creating freeform feature flags using AWS AppConfig and S3 objects. Manage application configurations and toggle features without redeploying.

Learn how to deploy a Hugo static site to S3 using AWS CodeBuild with a custom GoLang Docker image and a buildspec.yaml pipeline.

This article covers the buildspec.yaml file in AWS CodeBuild with practical examples for Node.js, Python, and Go projects. Includes the critical ECR login fix and EKS deployment patterns.

Search the blog for a topic, read the best matches, and synthesise a grounded answer with links.

Fetch the most relevant cheatsheet and summarise the commands or settings that answer a question.

Use the blog's comparison articles to weigh two technologies against each other on cost and fit.

Summarise the most recently published articles and what they cover.