This a personal Cheat sheet for Ubuntu (mostly server related stuff) + some MySQL and Docker commands. This page will be updated when I find useful commands 🙂
Guides
Disk
Show filsystem disk usage
df -h
Find what taking up diskspace
du -cha --max-depth=1 / | grep -E "M|G"
Database
Import / export mysql database
# Export mysqldump -u username -p databasename > filename.sql # Import mysql -u username -p databasename < filename.sql
Docker
Auto-start / restart docker-container
docker update --restart=always 0576df221c0b
# More "gentle" mode from the documentation:
docker run -dit --restart unless-stopped <image_name>
# Stop all running containers
docker stop $(docker ps -aq)
Kubernetes
# Deploy new version
kubectl rollout restart deployment/myapp-deployment
# Get pods (-o wide for more info)
kubectl get pod -o wide
# Bash inside pod
kubectl exec --stdin --tty myapp-1234-abcd -- /bin/bash
# Logs from pod (-f for follow)
kubectl logs -f myapp-1234-abcd
LAMP-stack
List installed PHP-extentions
sudo dpkg --list | grep php
# OR dpkg --get-selections | grep -i php
# OR php -m
# OR php -m | grep -i ftp
Check for avalible PHP-extentions
apt-cache search php | grep "^php7"
# OR apt-cache search php | grep "^php"
Log
Read log-file backwards:
tac filename | less
Check ssh login:
#Check for failed login
grep sshd.\*Failed /var/log/auth.log | less
# Check for accepted login
grep sshd.\*Accepted /var/log/auth.log | less
Troubleshoot
MySQL
#3009 - Column count of mysql.user is wrong. Expected 51, found 49. Created with MySQL 80012, now running 80015. Please use mysql_upgrade to fix this error.
mysql_upgrade --force -uroot -p
Full /boot
Soruce: https://gist.github.com/ipbastola/2760cfc28be62a5ee10036851c654600
sudo dpkg --list 'linux-image*'|awk '{ if ($1=="ii") print $2}'|grep -v `uname -r`
sudo rm -rf /boot/*-3.19.0-{25,56,58,59,61,65}-*
sudo apt-get -f install
sudo apt-get autoremove
sudo update-grub
sudo apt-get update