Unable to update Plex Media Server. Service not found.

Usually, this is a firewall problem… You need to make sure that BOTH tcp 53 and udp port 53 (DNS) are open. You probably have udp/53 open but not tcp/53.

-- sw

@stevewi Thanks for trying to help.

Apologies for my lack of knowledge here, if you can help further that would be appreciated.

I used "systemctl --type=service --state=running" to see if there was a firewall running. There wasn't anything listed. However UFW does seem to be running; "sudo ufw status" reveals there are no DNS ports open at all.

1) What is the reason UFW does not show up in the running services list?
2) What is the reason there is no plexmediaserver in the list either?

I added TCP/UDP 53 to UFW, this is confirmed using "sudo ufw status." This did not change any other behaviour, my first post still stands.

Am I missing something super obvious, like the plexmediaserver is not running directly on the hardware, but in a docker container? How do I then access it to update it? Now I'm running to people saying best practice is to never update a docker container, just replace it. How can I do that and keep my settings?

ufw is NOT the firewall. It's an Ubuntu-only "friendly front-end" to make the real firewall easy to use.

1) What is the reason UFW does not show up in the running services list?
2) What is the reason there is no plexmediaserver in the list either?

Neither of the services are running. Unless you tell systemd you want these things started at boot-up, it won't start them.

I added TCP/UDP 53 to UFW, this is confirmed using "sudo ufw status." This did not change any other behaviour, my first post still stands.

Unless ufw is running, it's not going to set up or change the real firewall appropriately.

Now I'm running to people saying best practice is to never update a docker container, just replace it. How can I do that and keep my settings?

I dunno…

-- sw

@stevewi

Neither of the services are running. Unless you tell systemd you want these things started at boot-up, it won't start them.

I'm able to stream from the media server, so it's running, but not in the way described in the original instructions, I'm thinking it's containerized. If that's the case, I don't see how the original instructions would have worked at all, unless Linode's pre-config'd Plex server roll-out process changed in the two years since their instructions were posted. As for ufw, sudo ufw status says "active" even though it's not in the running services list. This is normal?

@rdaniels

Are you able to chime in here? I followed the steps in your post but it's not working. I feel like I'm missing something super obvious, or the process has changed since your instructions posted over two years ago.

As for ufw, sudo ufw status says "active" even though it's not in the running services list. This is normal?

I dunno. I don't use Ubuntu.

-- sw

@stevewi

haha, neither do I, this is Debian. UFW is available in Debian though. https://wiki.debian.org/Uncomplicated%20Firewall%20%28ufw%29

Looks like UFW is a frontend for iptables, like firewalld. So it's not a service, iptables or nftables is the service.

I'm running Buster but I checked for /etc/nftables.conf on my install, it's not present. sudo iptables -L -n -v prints a big list of stuff, so I assume I'm running iptables and the changes made in UFW are reflected in iptables rules.

All of this to say, it appears I was in fact able to follow your first suggestion (opening DNS ports.)

I assume I'm running iptables and the changes made in UFW are reflected in iptables rules.

That would be the way it's supposed to work. IMHO, ufw is a crutch that's bad for you…especially bad because it comes from Ubuntu. I wouldn't trust it any farther than I can toss Mark Shuttleworth onto a football pitch. You should learn how to use iptables. This is a good reference:

https://www.amazon.com/Linux-iptables-Pocket-Reference-Gregor/dp/0596005695/ref=sr_1_1?crid=2CXJ6Y0EVNJ7P

With ipset, you can create rules that apply to tables of IPv4/IPv6 addresses & networks (specified by CIDR notation). You should install/learn ipset too:

https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/security_guide/sec-setting_and_controlling_ip_sets_using_iptables

-- sw

@stevewi

Wicked reference, thanks for the tip!