====== Helpful Ubuntu/Linux Commands and Procedures ======
----
=== List hard drive serial numbers ===
  lsblk --nodeps -o name,serial

=== List processes and the ports they are listening on ===
  netstat -tulpn | grep LISTEN
  
=== Reload systemd manager configuration after changes made ===
  sudo systemctl daemon-reload
  
=== List all installed packages ===
  apt list --installed 
  
=== Search for available packages ===
  apt-cache search <keyword>
  
=== Changing default editor for visudo ===
  sudo update-alternatives --config editor
  
=== Disable GUI screen lock ===
  Settings -> Privacy -> Screen Lock
  
=== Disable GUI screen blanking ===
  Settings -> Power -> Blank Screen
  
=== Create Samba User ===
  sudo smbpasswd -a <username>
  
=== List Samba Users ===
  sudo pdbedit -L
  
=== Determine the date the system was installed (not 100% reliable) ===
  tune2fs -l /dev/vda2 | grep ‘Filesystem created:’ (replace vda2 with device where root filesystem is located)
  
=== Finding largest files/directories ===
  du -a /dir/ | sort -n -r | head -n 20 (replace 20 with the # of lines you wish to have returned)

=== Disable colors in the vi editor by default ===
  Create (or edit, if it exists) ~/.vimrc; into this file add the command syntax off, and save the file.

**Overwrite/blast the boot block on the hard drive (<color red>ONLY when you want to re-install the operating system!</color>)**

  dd if=/dev/zero of=/dev/sda count=1 bs=512
  
=== Find files consuming the root file system ===
  mkdir /tmp/rootbind
  mount --bind / /tmp/rootbind
  du -d 1 -h /tmp/rootbind

=== Solution for Linux systems not visible in the "Network Neighborhood" on Windows machines ===
  apt install wsdd
  
=== View video resolution capabilities ===
  xrandr -q

=== Converting OTA DVR recordings to .MP4 ===
OTA DVR recordings are saved as **.ts** files, which are not compatible with DaVinci Resolve (my video editor of choice).  For this reason, we must convert the files into a format that “DR” can comprehend.  We can do this on linux using the ffmpeg package:
  ffmpeg -i <inputfile.ts> -vcodec copy -acodec copy <outputfile.mp4>
  
=== Generate password hashes (useful for Ansible playbooks amongst other things) ===
  mkpasswd --method=sha-512
==== Cookbook for passing client IP address to systems behind a reverse proxy ====
=== On the reverse proxy: ===
Ensure that websockets support is enabled

=== On the host: ===
Create /etc/apache2/conf-available/remoteip.conf with the following contents:
  RemoteIPHeader X-Forwarded-For
  RemoteIPTrustedProxy x.x.x.x (replace w/ IP address of trusted proxy)
  
Execute the commands:
  ln /etc/apache2/conf-available/remoteip.conf /etc/apache2/conf-enabled/remoteip.conf
  ln /etc/apache2/mods-available/remoteip.load /etc/apache2/mods-enabled/remoteip.load

Edit ''/etc/apache2/apache2.conf'' and find the **LogFormat** lines.  Change each occurrence of **%h** to **%a**.

Restart apache.