Setup our software

Our next goal is to install the software necessary for our Pi.

First we update our list of available software and then upgrade the software. We will use an operator to join two commands together. The first command updates the list of software and if that completes successfully, then the last part of the sequence, a software upgrade is started and any suggested files are auto installed.

sudo apt-get update && sudo apt-get upgrade -y 

Now we are going to upgrade the distribution, Raspbian, software. To ensure that our operating system is fully up to date.

sudo apt-get update && sudo apt-get dist-upgrade  
Once completed and the terminal is returned to you enter the next command to install the HTTPS transport package to enable access to HTTPS content over the Internet.
sudo apt-get install apt-transport-https -y --force-yes 
Next we shall download a key that will authenticate our downloads to ensure they are safe
wget -O - https://dev2day.de/pms/dev2day-pms.gpg.key  | sudo apt-key add -  
With the key downloaded we now add a new repository to our list, this repository is provided by dev2day.de who has worked on the packages that will power our Plex install.
echo "deb https://dev2day.de/pms/ jessie main" | sudo tee /etc/apt/sources.list.d/pms.list 
We now update our list again, to ensure that we now have the latest updates for the Plex Media Server.
sudo apt-get update
Lastly we install the Plex Media Server software.
sudo apt-get install -t jessie plexmediaserver -y  
The install will only take a few minutes and once completed the Plex Media Server will automatically start as a background service on your Pi. At this point it is worth rebooting your Raspberry Pi 3 as proceeding without a reboot caused a bug when trying to configure the Plex server via the browser.
sudo reboot
With your Pi rebooted we shall now test that we can access the Plex server. On your laptop or desktop PC open a web browser and type your IP address followed by :32400/web so for example I typed.
http://[ip address]:32400/web  
This will now open the Plex Media Server software and we will need to read and accept the Terms and Conditions before progressing. Once Plex has loaded take a few moments to get familiar with the interface. Specifically the libraries, which will house your media collection. The SD card of our Raspberry Pi is rather small, so let's add an external hard drive and store our media there. Plug in your USB drive (or external HDD), format as ext4 or FAT32. Nothing will happen in Plex until we mount the drive. In Linux, mounting a drive means that it is ready to be used. On your Raspberry Pi
sudo blkid -o full -s UUID
Example output
/dev/mmcblk0p1: UUID="7A90-EEEC"
/dev/mmcblk0p2: UUID="fbbfbe71-1286-488b-b04b-68ed6062b695"
/dev/sda1: UUID="eec011a5-ca8e-4aaf-aea7-4501c6d3c6b8"
Make dir named /mnt/library
sudo mkdir /mnt/library
Modify /etc/fstab file
sudo nano /etc/fstab
Add following line to end of file, replace ext4 as your HDD/FlashDrive file type
UUID=eec011a5-ca8e-4aaf-aea7-4501c6d3c6b8	/mnt/library	ext4	defaults	0	0
Reboot pi 3
sudo reboot
After system reboot, you should be able to see /mnt/library content, since it's local server, we going to enable access to all users
sudo chmod 777 -R /mnt/library

User guide

Open URL: http://plex.tv or http://[server ip address]:32400/

Signup new user

Add library

Select your type

Select type

Select folder (External driver here)

 

Now you can enjoy your movies. ;-D