r/docker • • 1h ago

Shadowing vital containers

• Upvotes

I have some critical containers on my home server (mainly Home Assistant and friends) that I can't live without. My whole home and life is dependent on them, lol. I already run RAID1c3 BTRFS, dual UPS and have a backup system in place. But it's impossible to eliminate every possible source of disasters. Especially on a modest budget.

I have an old Intel NUC to use as a shadow server for emergency failover.

  1. Docker Swarm - doesn't handle storage

  2. Kubernetes - apparently can handle storage but I'm told it's difficult.

  3. Bash scripts, SSH, BTRFS snapshots etc. - I'm pretty good at this stuff so it seems like the default approach. Wake the shadow up, update it, test it and send it back to sleep every interval.

What's the right answer?


r/docker • • 7h ago

Is there a way to have a multi container app update but keep all your saved settings?

1 Upvotes

I downloaded and ran Ganymede (https://github.com/zibbp/ganymede) a few months back, it has since updated but I have no idea if there’s a way to update it without starting from scratch as a new application?


r/docker • • 20h ago

I built a CLI that lets a local process join a Docker Swarm/Compose/k8s/okd cluster by name (no kubeconfig, no port-forwards)

2 Upvotes

I develop against Kube, Swarm and Compose stacks and got tired of port mappings and /etc/hosts edits, so I built plug. You prefix your usual command:

plug -s my-api:8080:3000 npm run start:dev

- Your process resolves cluster names (postgres, my-service:8080) as if it were a container. No code or proxy config, any runtime.

- The cluster reaches your process as my-api:8080. The name doesn't need to exist yet. If a deployed service already owns it, plug parks it for the session and restores it on exit.

- On a takeover it also inherits the service's environment, secret/config files and volumes (mounted over SMB, no FUSE).

- Docker, Compose, Swarm, Kubernetes. Linux, macOS, Windows. One agent container; developers only need the cluster's address.

Free, source-available. mirrord and Telepresence do similar things for Kubernetes; there's a side-by-side in the docs, including where they're ahead.

Repo: https://github.com/softwarity/plug

Docs: https://softwarity.github.io/plug/

I'd really like feedback from people: what would make this useful for your workflow?

PS: I tried to message the mods, but I get an error message.


r/docker • • 16h ago

Docker Desktop doesn't run persistently when start via ssh

1 Upvotes

Using Docker Desktop on Windows.

I'm new to Docker Desktop, so sorry for my ignorance. I've been able to start/stop docker desktop using "docker desktop stop" and "docker desktop start". The problem with "docker desktop start" is that while it does start docker desktop, docker desktop only lives as long as the terminal that started it is up. As soon as I kill my Terminal, Docker Desktop just dies.

The reason I pretty much need this, is because I only have 16 GB RAM, and Windows steals a quarter of it, while Docker Desktop steals half. I'm left with like a quarter of my RAM (which my browser wants to eat), so I'm left with almost no RAM left, which forces me to kill docker desktop (killing only containers isn't enough, since the linux vm itself is the main problem), while I actually use my pc. I tend to forget to boot up docker desktop again when leaving the pc, so a way to launch it persistently via ssh would be great. But that turned out to be harder than expected.


r/docker • • 19h ago

Mod Approved 50MB Challenge: can a real Java app fit in a 50MB Docker image?

0 Upvotes

https://youtu.be/2f0LUg5_GvQ 🎦

With cloud costs and bandwidth going up, I’m seeing more teams start to actually care about container size. Tried every way I could think of how to build a Java Docker image and compared the sizes.

Anyone else optimizing for size? or your team just never looks at the cloud bill?