MiniDLNA is a media server system that can be used to set up home theater systems. Specifically, I'm using it to run a multimedia server off a Raspberry Pi so that I can access MP3s on my Rokus. The MiniDLNA client is pretty good once it's going, but it's not easy to get going, and instructions found elsewhere on the internet may no longer be valid due to changes in the software or underlying OS. Therefore, I present my trial-and-error instructions for full setup. I have found no duplicate or extraneous steps unless noted... basically, following this set of steps front to end should work effectively, if not completely efficiently. But it's close.
Starting from scratch. These steps will guarantee that, if there is an old configuration floating around that didn't work, it won't interfere with the redo we're attempting.
sudo su
apt remove minidlna
apt purge minidlna
apt autoremove (expecting no result)
Reboot the RPi
Install the software
sudo su
apt update
apt full-upgrade (might as well, it's good practice)
apt install minidlna
Reboot the RPi
Confirm blank configuration is running
sudo systemctl daemon-reload
sudo systemctl status minidlna
The bottom two lines should indicate that the server was starting and then started successfully.
Perform basic configuration for media directories and users
Note: I'm using the nano text editor because it's easy to use over terminals, a plus for headless media servers like mine. It should work for various shells, and of course you can use gedit or whatever else you choose if you're headful.
sudo nano /etc/minidlna.conf
Add whatever media directories you feel like using the "media_dir=" entry. See <link to be inserted> for a good walkthrough.
Change the username to whatever your RPi's default user name is. You probably entered this during initial configuration of the Pi itself, and older systems running outdated version of Raspbian may still use "pi", a practice no longer recommended for security concerns. Basically, this should either be a dedicated account if you know what you're doing (which I don't), or whatever shows up when you type "whoami" in an empty terminal. If you get "root", you need to back out to a clean terminal.
Exit the conf file editor.
sudo nano /etc/default/minidlna
Comment out the USER="minidlna" and GROUP="minidlna" lines.
Replace them with USER=<username> and GROUP=<username>, where <username> is the same name you added in the /etc/mindlna.conf file above. Be sure to put them in quotes!
Exit the conf file editor.
sudo nano /lib/systemd/system/minidlna.service
Comment out the User=minidlna and Group=minidlna lines, and replace them lines to use "root". I understand this is bad practice but apparently it's necessary for this kind of setup.
Under the [Service] tag, add the line:
ExecStartPre=/bin/sleep 30
This will cause the minidlna service to wait 30 seconds after system boot before starting. This is important for my rig because the external drive that hosts my media files can take several seconds to mount to its location on /media, and if the service starts before the files are available, it leads to duplicated directories and an apparently-empty library. A 30-second wait may be pessimistic for many drives, especially SSDs, but it should be a safe value for your configuration
Exit the conf file editor.
Restart the service and check that the new media directory is present.
sudo systemctl daemon-reload
sudo systemctl restart minidlna
You should see two lines at the end of the status message saying the service was starting, and then that it started successfully. A nice green light at the top of the status window is also a quick feel-good.