Devops Cheat Sheet

Raw

Permission Cheat Sheet

You will use this one a lot in Wordpress :P

   chown -R www-data:www-data ./
   // set the proper owner

   find . -type f -exec chmod 644 {} \+
   // Recursively set FILE permissions.

   find . -type d -exec chmod 755 {} \+
   // Recursively set DIRECTORY permission

Some Devops Cheat Sheet

Change the $VAR sign with the appropriate variables

  ps auxww -H
  // to check running process and show hierarchies (child-parent)

  pgrep -fl php
  // PHP related processes

  strace -f -p $PID
  // What is the process doing

  lsof -p $PID
  // What files the process open?

  kill xxxx
  kill xxxx yyyy zzzz
  pkill <name of process>
  pkill -f <word in process name>
  // many ways to Kill

  watch 'ps aux | grep ruby'
  // Keep an eye of a process

  free -m
  cat /proc/meminfo
  // Check for Free memory

  vmstat 1
  // Are we swapping?

  ps aux --sort=-resident|head -11
  // Check for memory hoggers (one who leak?)

  lsof -nPi tcp
  // TCP in use

  ip addr
  ifconfig
  // IP

  host 192.1.1.1
  host myrouter
  // Host -> IP resolution

  curl -LI http://google.com
  // Curl header (and follow redirect)

  tcptraceroute google.com
  // Traceroute using TCP (install it if it's not exists)

  iptables -L
  // List all blocking rules

  netstat -tlnp 
  // Show all listeners (servers)

   wget cachefly.cachefly.net/100mb.test -O /dev/null
   // Speedtest (Do not run in production!)

Raw

File And Disk Related

Sort Top 10 directories by size

du -sk * | sort -nr | head -10

List files marked of deletion, but not deleted yet

  lsof | grep delete

Your disk overview

  df -h

Usage of this dir and sub-dirs

  du -hs

Find file over 100megs

  find . -size +100M

List tmp - you can remove these

  ls -al /tmp

List files created within 7 days

  find . -mtime -7

Find .gz files older than 14 days

  find . -mtime +14 -type f -name '*.gz'

Monitor a log file

  tail -f file.log | grep 192.168.1.1

Remove specific files

	find ./vendor -type d -name .git | xargs rm -rf
	find ./vendor -type d -name .bzr | xargs rm -rf
	find ./vendor -type d -name .hg | xargs rm -rf

Raw

User And Session Related

  lastlog
  // Get list of users, and when they are last logging-in

  who
  // list of all active sessions

  cat /etc/group
  
  groups
  
  // Get list of all groups

   // add user to a group
   sudo adduser user group

   // remove user from a group
   sudo deluser user group