Why DevOps Beginners Quit Too Early: The Real Reason

Errors that make beginners quit - and what they mean

"Permission denied"
  -> your user lacks rights to that file or command
  -> check: ls -l file ; whoami ; use sudo only if needed

"Address already in use"
  -> another process already uses that port
  -> check: sudo ss -tulpn | grep 8080

"command not found"
  -> tool not installed or not in PATH
  -> check: which docker ; echo $PATH

"Connection refused"
  -> nothing is listening, or a firewall blocks it
  -> check the service is running and the port is right

Am I learning DevOps in the right order?

[ ] I can navigate Linux and edit files in the terminal
[ ] I understand users, groups and permissions
[ ] I know what IP, port and DNS mean
[ ] I commit and push code with Git daily
[ ] I have built and run my own Docker image
[ ] I have one pipeline that runs automatically

Unticked early items? Go back - it will speed you up.

# Daily Linux practice (run on your own machine or VM)
mkdir -p ~/practice/logs && cd ~/practice
echo "app started" > logs/app.log
echo "error: disk full" >> logs/app.log

grep -i "error" logs/app.log        # find errors
wc -l logs/app.log                  # count lines
chmod 640 logs/app.log              # owner rw, group r
ls -l logs/                         # check permissions
ps aux | head -5                    # running processes
df -h                               # disk usage

# Git basics every DevOps beginner needs
git init demo && cd demo
echo "# Demo" > README.md
git add README.md
git commit -m "Add README"

git switch -c feature/health-check
echo "status: ok" > health.txt
git add health.txt
git commit -m "Add health check file"

git switch main
git merge feature/health-check
git log --oneline --graph

# .github/workflows/ci.yml
name: CI

on:
  push:
    branches: [main]
  pull_request:

jobs:
  build-and-test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
      - run: pip install -r requirements.txt
      - run: python -m pytest
      - run: docker build -t demo-app .

# DevOps Starter Project

## What it does
Small web app with a /health endpoint.

## Pipeline
Push -> tests -> Docker build -> (optional) deploy

## Run locally
docker build -t demo-app .
docker run -p 8000:8000 demo-app

## What I learnt
- Fixed a failing pipeline caused by a missing dependency
- Reduced image size with a slim base image

## Next steps
Add monitoring and deploy with a cloud service

Layer Tracker

Layer     Status           Small win done?   Date
Linux     learning / done  Y / N             ____
Git       learning / done  Y / N             ____
Docker    learning / done  Y / N             ____
CI/CD     learning / done  Y / N             ____
Cloud     learning / done  Y / N             ____

Current layer only. Do not start the next one early.

Error Journal

Date: ____
Error message: _______________
What I was doing: _______________
What I tried: _______________
Real cause: _______________
Fix: _______________
Lesson for next time: _______________

Weekly Check-in

Hours practised: ____
Commands / tools I can now use without notes:
1. ___  2. ___  3. ___
Something I fixed myself: _______________
Something I am stuck on: _______________
Who can I ask? _______________
Compared with last month, I can now: _______________