Uncloud - Tool for deploying containerised apps across servers without k8s

Hey, creator here. Thanks for sharing this!

Uncloud[0] is a container orchestrator without a control plane. Think multi-machine Docker Compose with automatic WireGuard mesh, service discovery, and HTTPS via Caddy. Each machine just keeps a p2p-synced copy of cluster state (using Fly.io's Corrosion), so there's no quorum to maintain.

I’m building Uncloud after years of managing Kubernetes in small envs and at a unicorn. I keep seeing teams reach for K8s when they really just need to run a bunch of containers across a few machines with decent networking, rollouts, and HTTPS. The operational overhead of k8s is brutal for what they actually need.

A few things that make it unique:

- uses the familiar Docker Compose spec, no new DSL to learn

- builds and pushes your Docker images directly to your machines without an external registry (via my other project unregistry [1])

- imperative CLI (like Docker) rather than declarative reconciliation. Easier mental model and debugging

- works across cloud VMs, bare metal, even a Raspberry Pi at home behind NAT (all connected together)

- minimal resource footprint (<150MB ram)

[0]: https://github.com/psviderski/uncloud

[1]: https://github.com/psviderski/unregistry

How's this similar to and different from Kamal? https://kamal-deploy.org/

"I keep seeing teams reach for K8s when they really just need to run a bunch of containers across a few machines"

Since k8s is very effective at running a bunch of containers across a few machines, it would appear to be exactly the correct thing to reach for. At this point, running a small k8s operation, with k3s or similar, has become so easy that I can't find a rational reason to look elsewhere for container "orchestration".

You have a graph that shows a multi provider setup for a domain. Where would routing to either machine happen? As in which ip would you use on the dns side?

100%. I’m really not sure why K8S has become the complexity boogeyman. I’ve seen CDK apps or docker compose files that are way more difficult to understand than the equivalent K8S manifests.

does it support ipv6?

I took some inspiration from Kamal, e.g. the imperative model but kamal is more a deployment tool.

In addition to deployments, uncloud handles clustering - connects machines and containers together. Service containers can discover other services via internal DNS and communicate directly over the secure overlay network without opening any ports on the hosts.

As far as I know kamal doesn’t provide an easy way for services to communicate across machines.

Services can also be scaled to multiple replicas across machines.

How does this compare to k3s?

There is an open issue that confirms enabling ipv6 for containers works: https://github.com/psviderski/uncloud/issues/126 But this hasn’t been enabled by default.

What specifically do you mean by ipv6 support?

Thanks! I noticed afterwards that you mention Kamal in your readme, but you may want to add a comparison section that you link to where you compare your solution to others.

Are you working on this full time and if so, how are you funding it? Are you looking to monetize this somehow?

That’s awesome if k3s works for you, nothing wrong with this. You’re simply not the target user then.

Very cool! I think I'll have some opportunity soon to give it a shot, I have just the set of projects that have been needing a tool like this. One thing I think I'm missing after perusing the docs however is, how does one onboard other engineers to the cluster after it has been set up? And similarly, how does deployment from a CI/CD runner work? I don't see anything about how to connect to an existing cluster from a new machine, or at least not that I'm recognizing.

Thank you for the suggestion!

I’m working full time on this, yes. Funding from my savings at the moment and don’t have plans for any external funding or VC.

For monetisation, considering building a self-hosted and managed (SaaS) webUI for managing remote clusters and apps on them with value-added PaaS-like features.

That sounds interesting, maybe I could help on the business side of things somehow. I'll email you my calendar link.

Neat, as you include quite a few tool for services to be reachable together (not necessarily to the outside), do you also have tooling to make those services more interoperable?

Having spent most of my career in kubernetes (usually managed by cloud), I always wonder when I see things like this, what is the use case or benefit of not having a control plane?

To me, the control plane is the primary feature of kubernetes and one I would not want to go without.

I know this describes operational overhead as a reason, but how it relates to the control plane is not clear to me. even managing a few hundred nodes and maybe 10,000 containers, relatively small - I update once a year and the managed cluster updates machine images and versions automatically. Are people trying to self host kubernetes for production cases, and that’s where this pain comes from?

Sorry if it is a rude question.

I can only speak for myself, but I considered a few options, including "simple k8s" like [Skate](https://skateco.github.io/), and ultimately decided to build on uncloud.

It was as much personal "taste" than anything, and I would describe the choice as similar to preferring JSON over XML.

For whatever reason, kubernetes just irritates me. I find it unpleasant to use. And I don't think I'm unique in that regard.

Does it support a way to bundle things close to each other, for example, not having a database container hosted in a different datacenter than the web app?

> Are people trying to self host kubernetes

Of course they are…? That’s half the point of k8s - if you want to self host, you can, but it’s just like backups: if you never try it, you should assume you can’t do it when you need to

There isn't a cli function for adding a connection (independently of adding a new machine/node) yet, but they are in a simple config file (`~/.config/uncloud/config.yaml`) that you can copy or easily create manually for now. It looks like this:

    current_context: default
    contexts:
      default:
        connections:
          - ssh: admin@192.168.0.10
            ssh_key_file: ~/.ssh/uncloud
          - ssh: admin@192.168.0.11
            ssh_key_file: ~/.ssh/uncloud
          - ssh: administrator@93.x.x.x
            ssh_key_file: ~/.ssh/uncloud
          - ssh: sysadmin@65.x.x.x
            ssh_key_file: ~/.ssh/uncloud

And you really just need one entry for typical use. The subsequent entries are only used if the previous node(s) are down.

Not OP, but you could do "simple" dns load balancing between both endpoints.

> What specifically do you mean by ipv6 support?

This question does not make sense. This is equivalent to asking "What specifically do you mean by ipv4 support"

These days both protocols must be supported, and if there is a blocker it should be clearly mentioned.

The `compose.yaml` spec for services let's you specify which machines to deploy it on, so you could target the database and web app to the same machine (or subset of machines).

There is also an internal DNS for service discovery and it supports a `nearest.` prefix, which will preferentially use instances of a service running on the same machine. For example, I run a globally replicated NATS service and then connect to it from other services using the `nearest.nats.internal` address to connect to the machine-local NATS node.

If you already know k8s, this is probably true. If you don't it's hard to know what bits you need, and need to learn about, to get something simple set up.

Not rude at all. The benefit is a much simpler model where you simply connect machines in a network where every machine is equal. You can add more, remove some. No need to worry about an HA 3-node centralised “cluster brain”. There isn’t one.

It’s a similar experience when a cloud provider manages the control plane for you. But you have to worry about the availability when you host everything yourself. Losing etcd quorum results in an unusable cluster.

Many people want to avoid this, especially when running at a smaller scale like a handful of machines.

The cluster network can even partition and each partition continues to operate allowing to deploy/update apps individually.

That’s essentially what we all did in a pre-k8s era with chef and ansible but without the boilerplate and reinventing the wheel, and using the learnings from k8s and friends.

Awesome tool! Does it provide some basic features that you would get from running a control plane.

Like rescheduling automatically a container on another server if a server is down? Deploying on the less filled server first if you have set limits in your containers?

If not K8S, why not Nomad (https://github.com/hashicorp/nomad)?

> a few hundred nodes and maybe 10,000 containers, relatively small

That feels not small to me. For something I'm working on I'll probably have two nodes and around 10 containers. If it works out and I get some growth, maybe that will go up to, say, 5-7 nodes and 30 or so containers? I dunno. I'd like some orchestration there, but k8s feels way too heavy even for my "grown" case.

I feel like there are potentially a lot of small businesses at this sort of scale?

Indeed, it seems a knee jerk response without justification. k3s is pretty damn minimal.

k3s uses sqlite, so not etcd.

Nomad is great, but you will still end up with a control plane.

Looks lovely.. I'll definitely will give it a try when time comes.

This is extremely interesting to me. I've been using docker swarm, but there is this growing feeling of staleness. Dokku feels a bit too light, K8 absolutely too heavy. This proposition strikes my sweet spot - especially the part where I keep my existing docker compose declarations

Do you have an example of what you mean? I'm not entirely clear on your question.

Managing hundreds or thousands of containers across hundreds or thousands of k8s nodes has a lot of operational challenges.

Especially in-house on bare metal.

Thanks for the both great tools. just i didn't understand one thing ? the request flow, imaging we have 10 servers where we choose this request goes to server 1 and the other goes to 7 for example. and since its zero down time, how it says server 5 is updating so till it gets up no request should go there.

Isn't Nomad pretty much dead now?

Try it on bare metal where you're managing the distributed storage and the hardware and the network and the upgrades too :)

As a happy user of coolify, what’s the difference between these two?

Even coolify lets you add as many machines as you want and then manage docker containers in all machines from one coolify installation.

Awesome, will reach out!

haha, uncloud does have a control plane: the mind of the person running "uc" CLI commands

> I’m building Uncloud after years of managing Kubernetes

did you manage Kubernetes, or did you make the fateful mistake of managing microk8s?

How do you want to allocate ipv6 addresses to containers? Turns out there are lots of answers. Some people even want to do ipv6 NAT.

How does this compare to something like Dokku?