I'm running a Docker-based homelab that I manage primarily via Portainer, and I'm struggling with how to handle container updates. At first, I had all containers pulling latest, but I thought maybe this was a bad idea as I could end up updating a container without intending to. So, I circled back and pinned every container image in my docker-compose files.
Then I started looking into how to handle updates. I've heard of Watchtower, but I noticed the Linuxserver.io images all recommend not running Watchtower and instead using Diun. In looking into it, I learned it will notify you of updates based on the tag you're tracking for the container, meaning it will never do anything for my containers pinned to a specific version. This made me think maybe I've taken the wrong approach.
What is the best practice here? I want to generally try to keep things up to date, but I don't want to accidentally break things. My biggest fear about tracking latest is that I make some other change in a docker-compose and update the stack which pulls latest for all the container in that stack and breaks some of them with unintended updates. Is this a valid concern, and if so, how can I overcome it?
I've never used Portainer, but does it have an option to only notify of available updates?
For things that I don't mind breaking, I use latest. For the services that matter, use a specific version. Take Immich for example, in the 2-3 months I've kept it running, there's been 3 breaking changes that would prevent startup after update without manual intervention. Immich is an extreme though, some other projects have been working fine with latest without touching them for years.
I follow the important projects' releases (subacribe if possible), and update manually when they publish an image with a new version. I'd see it as either updating manually and being OK about possibly being a version behind every now and then, or using latest+auto updates and being OK with waking up to broken services every now and then. Which might never happen.
I don't believe Portainer can notify of available updates. I can achieve this with Diun, but only within the tag specified in my docker-compose.