Tag: devops

Twenty powerful bash one-liners every sysadmin should know, file ops, process hunting, networking, text processing, disk analysis

Compile software on Raspberry Pi or cheap VPS with 512MB, 2GB RAM. Swap, parallel jobs, ccache, and swappiness tuning make it work.

Three ways to set env vars in Docker Compose. Only one wins. Here's which and why it breaks your configs.

ENV bakes secrets into layers visible in docker history. Use BuildKit --secret, runtime vars, or .env files.

Build ARM64 and AMD64 images from one machine using Docker buildx. Setup, syntax, pushing multi-arch manifests, and when you actually need it.

The docker compose commands you actually use daily, up, down, logs, exec, pull, and the flags that make them way more useful.

Access services on the host machine from inside a Docker container using host-gateway or host.docker.internal, no hardcoded IPs.

Learn how to set Docker resource limits for memory, CPU, swap, and PIDs. Practical guide with real-world sizing examples, OOM killer behavior, and cgroups explained.

The -v and --mount flags for Docker volumes explained, bind mounts vs named volumes, read-only, propagation, and tmpfs options.

COPY and ADD look similar but ADD auto-extracts tarballs and fetches URLs, know when each is appropriate and why COPY is usually better.

Add load balancing and failover to your Docker setup using Swarm, nginx, HAProxy, and Keepalived, high availability without Kubernetes.

Shell globbing breaks inside docker exec because of how args are parsed, here's how to pass wildcards and asterisks correctly.