DevOps Assignment

Name: Soham Ambore Enrollment Number: 24bcs10258

All seven homework topics, each in its own folder with its own README.md. Every command output committed here was actually executed — no output is fabricated. Each folder also contains the script that produced it and a full-transcript.txt of the unedited run, so anything can be reproduced.

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Submission links

#	Topic	Folder	README
1	Git and GitHub	01-git-github	README.md
2	Linux Fundamentals	02-linux-fundamentals	README.md
3	Shell Scripting	03-shell-scripting	README.md
4	Networking	04-networking	README.md
5	Docker Fundamentals	05-docker-fundamentals	README.md
6	Docker Images	06-docker-images	README.md
7	Docker Networking	07-docker-networking	README.md

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What each deliverable covers

1. Git and GitHub

git commit -a -m vs git commit -m demonstrated with a real failing commit, plus proof that -a silently skips untracked files. Cherry-pick performed across two branches with git log --graph showing the picked commit landing on main under a new SHA.

2. Linux Fundamentals

Run on Ubuntu 26.04 LTS (WSL2) with systemd enabled.

• Soft vs hard links — inode numbers, link counts, and the decisive test: deleting the original leaves the hard link working and the soft link dangling.
• adduser vs useradd — both used; useradd leaves no home directory, adduser creates home, skel files, shell and group.
• journalctl — system logs, boot logs, per-unit logs, priority and time filters, disk usage.
• Command cheat sheet — ~40 commands executed across navigation, files, search, permissions, processes, disk, archives and packages.

3. Shell Scripting

sysinfo.sh prints date, hostname, username, disk usage and running processes; uses variables throughout; takes input via read -p; creates a directory with mkdir and a file with touch; and writes ps -ef into that file with > redirection.

4. Networking

Every command run on Ubuntu with output and a written explanation of what it means: ip addr, ifconfig, ip route, ping, traceroute, dig, nslookup, host, ss, netstat, nc -z, curl, wget, ip neigh, arp.

5. Docker Fundamentals

Six Hello World web applications, each in its own folder with its own Dockerfile, all six built and verified HTTP 200: Node.js, Python, Java, Apache, React and Nginx.

6. Docker Images

Multi-stage Dockerfile serving "Hello World from Docker multi-stage build" on port 8080, verified with docker ps. Includes a measured comparison against a single-stage build of the same app: 441 MB → 6.87 MB, roughly 64× smaller.

7. Docker Networking

Three containers across three networks with the backend attached to two, showing frontend→database isolation failing at the DNS layer. Plus host networking with Apache, a live-reloading bind mount, and a real overlay network on an initialised Swarm with a 2-replica service.

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Environment

Component	Version
Host OS	Windows 11
Linux	Ubuntu 26.04 LTS on WSL2, kernel 6.18.33.2, systemd enabled
Docker	29.7.2 (Docker Desktop, Linux containers)
Git	2.51.1

Notes

• Two values were redacted before publishing: the machine's public IP (in 04-networking) and a Swarm join token (in 07-docker-networking).
• 06-docker-images documents one assumption about the source repository — see the note at the top of that README.