I'm still pretty new to learning Docker etc., and I'd love to get pihole running on it too on my little Jammy server instead of the aging Pi it's currently on - one less machine to have plugged in and all - but I was wondering how to revert the OS settings required to change, in case I decide to remove the container? I tried installing it before and had to remove it, but in doing so, I think Ubuntu freaked out a little (it might have been unrelated), and I'd love to know how to properly reset the "stock" settings that change when installing pihole.
I'm pretty sure the original file could be backed up and restored (somehow - by fixing the symlink?) but if I get too in the weeds with some things, I get confused. Name resolution etc. isn't something I want to get confused with! lol
Thanks for any help anyone has. I hope this isn't too redundant or repetitive, I didn't find many answers pertaining to "if you want to REMOVE your pihole container, do this to revert the changes" questions.
Oh I think I see - looking closer, it seems like the original file is backed up with a .orig extension, and it would just be a matter of redoing the symlink (but in reverse). Basically then: follow that section in reverse, change the symlink back to the .orig file (after replacing the resolv.conf with resolv.conf.orig - do I have that right)?
I'd imagine that from Docker's perspective Pi-hole is just another container which you can deploy and remove like any other. Any config changes before and after would be external to Docker in order to use the container for its intended purpose, and then ensuring that volumes are preserved or destroyed as needed, same as with other containers. I've not used Docker so hopefully someone else can advise on any Pi-hole specifics.
Right - what I'm trying to clarify is all the external, OS/systemd changes that have to be made with Ubuntu. I've got the Docker stuff mostly figured out.
My general suggestion for handling this sort of thing is to make regular backups. Especially when installing in a way that involves other components. To me, it is a lot easier than trying to figure out after the fact what something has changed is bit more difficult.
As you have used Docker, I cannot image that unless someone here has full knowledge of what was changed. Even if they did, the OS bits changed by something like Docker have likely changed with time.
Good luck, as this really is something I am not fully knowledgeable on, and would instead have made regular backups to handle.
You are correct - backups are always good. This is not about Docker specifically though, it just happens to be the install route I am using. As I linked in my original question, I'm trying to clarify (and make sure I'm understanding) how to revert the steps made to resolv.conf, the symlinking, and systemd; the steps which are needed on Ubuntu regardless of Docker or bare metal installs, according to the linked Pihole documentation. Even with a backup, it would seem/I would think the symlinks need to be repaired to restore Ubuntu back to its normal name resolution techniques.
The Docker stuff I've got figured out, that's not the focus of the question.
If you didn't take notes on what you changed, we don't know exactly how to help you.
If you disabled some services you need to re-enable them, but I'm not sure which services you disabled (or uninstalled) in Ubuntu.
I think your version of Ubuntu uses "Network Manager".
I found a few links searching for "Ubuntu 22 resolv.conf", like these:
I followed the steps in the Pihole documentation I linked in my question. To be clear, this is informational at this point - nothing is broken as I haven't installed Pihole onto this machine yet. I just want to better understand the documentation, better know the steps to uninstall - other than just removing the image, as it states - and possibly help improve it through questioning it.