Developer Essentials

Comprehensive developer cheatsheets and quick references for Git, Docker, Kubernetes, jq, curl, and common Linux commands. Use when needing quick lookups for command syntax, common workflows, or forgotten flags for everyday developer tools.

Developer Essentials Cheatsheets

Quick references for everyday developer tools. Copy-paste ready commands.

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📚 Git Cheatsheet

Basic Commands

# Initialize repo
git init

# Clone repo
git clone <url>
git clone --depth 1 <url>          # Shallow clone (faster)

# Status & info
git status
git log --oneline -n 10
git diff
git diff --staged

Staging & Commits

git add .                           # Stage all
git add -p                          # Stage interactively
git commit -m "message"
git commit --amend                  # Edit last commit
git commit --amend --no-edit        # Keep message

Branches

git branch                          # List branches
git branch -a                       # List all (including remote)
git checkout -b <name>              # Create & switch
git switch <name>                   # Switch branch
git merge <branch>
git rebase <branch>

Push & Pull

git push origin <branch>
git push -u origin <branch>         # Set upstream
git pull
git pull --rebase
git fetch origin

Undo & Fix

git restore <file>                  # Discard changes
git restore --staged <file>         # Unstage
git reset HEAD~1                    # Undo last commit (keep changes)
git reset --hard HEAD~1             # Destroy last commit
git stash
git stash pop

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🐳 Docker Cheatsheet

Images

docker images                       # List images
docker pull <image>
docker build -t <name> .
docker build -t <name> -f Dockerfile.dev .
docker rmi <image>
docker image prune

Containers

docker ps                           # Running containers
docker ps -a                        # All containers
docker run -d -p 8080:80 <image>   # Detach + port
docker run -it --rm <image> bash    # Interactive + remove
docker exec -it <container> bash
docker logs -f <container>          # Follow logs
docker stop <container>
docker rm <container>
docker rm -f <container>            # Force remove

Docker Compose

docker compose up -d
docker compose down
docker compose logs -f
docker compose restart
docker compose build

Cleanup

docker system prune -a              # Remove all unused
docker system df                    # Disk usage

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☸️ Kubernetes (kubectl) Cheatsheet

Context & Config

kubectl config get-contexts
kubectl config use-context <name>
kubectl cluster-info

Get Resources

kubectl get pods
kubectl get pods -A                 # All namespaces
kubectl get services
kubectl get deployments
kubectl get nodes
kubectl get ns                      # Namespaces
kubectl get all

Describe & Debug

kubectl describe pod <pod>
kubectl logs <pod>
kubectl logs -f <pod>               # Follow
kubectl exec -it <pod> -- bash
kubectl top pods                    # Resource usage
kubectl top nodes

Apply & Delete

kubectl apply -f manifest.yaml
kubectl apply -k ./                 # Kustomize
kubectl delete -f manifest.yaml
kubectl delete pod <pod>

Quick Actions

kubectl expose deployment <name> --port=80 --type=LoadBalancer
kubectl scale deployment <name> --replicas=3
kubectl rollout restart deployment/<name>

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🔍 jq Cheatsheet (JSON Processor)

Basic Queries

# Identity (pretty print)
jq '.' file.json

# Get field
jq '.name' file.json
jq '.user.name' file.json

# Array index
jq '.[0]' file.json
jq '.[0].name' file.json

Array Operations

# Array length
jq '. | length' file.json

# All items in array
jq '.[]' file.json

# Map - extract field from array
jq '.[].name' file.json
jq '.[] | {name, email}' file.json

# Filter array
jq '.[] | select(.age > 30)' file.json
jq '.[] | select(.status == "active")' file.json

Transformations

# Create new object
jq '{user: .name, email: .contact.email}' file.json

# Add/remove fields
jq '. + {timestamp: now}' file.json
jq 'del(.password)' file.json

Useful Flags

jq -r '.name' file.json             # Raw output (no quotes)
jq -c '.' file.json                 # Compact (one line)
jq -s '.' file1.json file2.json     # Slurp multiple files

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🌐 curl Cheatsheet

Basic Requests

curl https://api.example.com
curl -I https://example.com         # Headers only
curl -v https://example.com         # Verbose

HTTP Methods

curl -X POST https://api.example.com/data
curl -X PUT https://api.example.com/data/1
curl -X DELETE https://api.example.com/data/1

Headers & Body

curl -H "Content-Type: application/json" \
     -H "Authorization: Bearer token" \
     https://api.example.com

curl -X POST -d '{"name":"test"}' \
     -H "Content-Type: application/json" \
     https://api.example.com

curl -X POST --data @file.json https://api.example.com

Output & Download

curl -o output.json https://api.example.com
curl -O https://example.com/file.zip  # Save with original name
curl -L https://example.com           # Follow redirects

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🐧 Linux Essential Commands

File Operations

ls -la                              # List all (including hidden)
cp -r source dest                   # Copy recursive
mv old new                          # Move/rename
rm -rf dir                          # Remove recursive force
mkdir -p path/to/dir                # Create parents too
touch file
chmod 755 file
chown user:group file

Search & Find

grep "pattern" file.txt
grep -r "pattern" .                 # Recursive
grep -i "pattern" file.txt          # Case insensitive
find . -name "*.txt"
find . -type f -size +100M          # Files > 100MB

Process Management

ps aux                              # All processes
top                                 # Interactive process viewer
htop                                # Better top (if installed)
kill -9 <pid>                       # Force kill
pkill -f process_name

System Info

df -h                               # Disk usage
free -h                             # Memory
uname -a                            # System info
whoami
pwd                                 # Current directory

Text Processing

cat file.txt
head -20 file.txt
tail -f log.txt                     # Follow file
less file.txt
wc -l file.txt                      # Line count
sort file.txt
uniq file.txt

Network

ifconfig / ip addr
netstat -tulpn                      # Listening ports
ss -tulpn                           # Modern netstat
ping example.com
curl ifconfig.me                    # Get public IP
ssh user@host
scp file.txt user@host:/path

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💡 Pro Tips

1. Use man <command> for full documentation
2. Use --help flag on most commands
3. Pipe commands together: ps aux | grep nginx
4. History search: Press Ctrl+R in terminal
5. Aliases save time - add to ~/.bashrc or ~/.zshrc