The Principal Dev – Masterclass for Tech Leads

The Principal Dev – Masterclass for Tech LeadsNov 27-28

Join
Uncloud logo

Uncloud

Docker simplicity. Multi-machine power.

Documentation Join Discord Follow on X Donate

Uncloud is a lightweight clustering and container orchestration tool that lets you deploy and manage web apps across cloud VMs and bare metal with minimised cluster management overhead. It creates a secure WireGuard mesh network between your Docker hosts and provides automatic service discovery, load balancing, ingress with HTTPS, and simple CLI commands to manage your apps.

Unlike traditional orchestrators, there's no central control plane and quorum to maintain. Each machine maintains a synchronised copy of the cluster state through peer-to-peer communication, keeping cluster operations functional even if some machines go offline.

Uncloud is the solution for developers who want the flexibility of self-hosted infrastructure without the operational complexity of Kubernetes.

✨ Features

🚀 Coming soon

🎬 Quick demo

The screenshot below demonstrates how I use Uncloud to deploy https://uncloud.run website to 2 remote machines from the compose.yaml file on my local machine.

It exposes the container port 8000/tcp as HTTPS on the domain uncloud.run, served by the Caddy reverse proxy on the remote machines. All managed by Uncloud.

Uncloud compose deployment demo

Here is a more advanced use case. Deploy a highly available web app with automatic HTTPS across multiple regions and on-premises in just a couple minutes.

Uncloud demo

💫 Why Uncloud?

Modern cloud platforms like Heroku and Render offer amazing developer experiences but at a premium price. Traditional container orchestrators like Kubernetes provide power and flexibility but require significant operational expertise. I believe there's a sweet spot in between — a pragmatic solution for the majority of us who aren't running at Google scale. You should be able to:

Uncloud's goal is to make deployment and management of containerised applications feel as seamless as using a cloud platform, whether you're running on a $5 VPS, a spare Mac mini, or a rack of bare metal servers.

🚀 Quick start

  1. Install Uncloud CLI:

    brew install psviderski/tap/uncloud
    
    # or using curl (macOS/Linux)
    curl -fsS https://get.uncloud.run/install.sh | sh
    

    See Installation for more options.

  2. Initialise your first machine:

    uc machine init root@your-server-ip
    
  3. Deploy your app from a Docker image and publish its container port 8000 as HTTPS using app.example.com domain:

    uc run -p app.example.com:8000/https image/my-app
    
  4. Create a DNS A record in your DNS provider (Cloudflare, Namecheap, etc.) that points app.example.com to your server's IP address. Allow a few minutes for DNS propagation.

    That's it! Your app is now running and accessible at https://app.example.com ✨

  5. Clean up when you're done:

    uc ls
    # Copy the service name from the output and run the rm command:
    uc rm my-app-name
    

    If you want to fully uninstall Uncloud on a machine, run:

    uncloud-uninstall
    

View the Documentation for more information.

⚙️ How it works

Check out the design document to understand Uncloud's design philosophy and goals.

Here is a diagram of an Uncloud multi-provider cluster of 3 machines:

Diagram: multi-provider cluster of 3 machines

Peek under the hood to see what happens when you run certain commands.

When you initialise a new cluster on a machine:

$ uc machine init --name oracle-vm ubuntu@152.67.101.197

Downloading Uncloud install script: https://raw.githubusercontent.com/psviderski/uncloud/refs/heads/main/scripts/install.sh
 Running Uncloud install script...
 Docker is already installed.
 Installing Docker...
...
 Docker installed successfully.
 Linux user and group 'uncloud' created.
 Linux user 'ubuntu' added to group 'uncloud'.
 Installing Uncloud binaries...
 Downloading uncloudd binary: https://github.com/psviderski/uncloud/releases/latest/download/uncloudd_linux_arm64.tar.gz
 uncloudd binary installed: /usr/local/bin/uncloudd
 Downloading uninstall script: https://raw.githubusercontent.com/psviderski/uncloud/refs/heads/main/scripts/uninstall.sh
 uncloud-uninstall script installed: /usr/local/bin/uncloud-uninstall
 Systemd unit file created: /etc/systemd/system/uncloud.service
Created symlink /etc/systemd/system/multi-user.target.wants/uncloud.service /etc/systemd/system/uncloud.service.
 Downloading uncloud-corrosion binary: https://github.com/psviderski/corrosion/releases/latest/download/corrosion-aarch64-unknown-linux-gnu.tar.gz
 uncloud-corrosion binary installed: /usr/local/bin/uncloud-corrosion
 Systemd unit file created: /etc/systemd/system/uncloud-corrosion.service
 Starting Uncloud machine daemon (uncloud.service)...
 Uncloud machine daemon started.
 Uncloud installed on the machine successfully! 🎉
Cluster "default" initialised with machine "oracle-vm"
Waiting for the machine to be ready...

Reserved cluster domain: xuw3xd.cluster.uncloud.run
[+] Deploying service caddy 1/1
 Container caddy-c47x on oracle-vm  Started                                                                                                                                          0.9s

Updating cluster domain records in Uncloud DNS to point to machines running caddy service...
[+] Verifying internet access to caddy service 1/1
 Machine oracle-vm (152.67.101.197)  Reachable                                                                                                                                       0.1s

DNS records updated to use only the internet-reachable machines running caddy service:
  *.xuw3xd.cluster.uncloud.run  A 152.67.101.197
  1. The CLI SSHs into the machine and installs Docker, the uncloudd machine daemon and corrosion service, managed by systemd.
  2. Generates a unique WireGuard key pair, allocates a dedicated subnet 10.210.0.0/24 for the machine and its containers, and configures uncloudd accordingly. All subsequent communication happens with uncloudd through its gRPC API over SSH.
  3. Configures and starts corrosion, a CRDT-based distributed SQLite database to share cluster state between machines.
  4. Creates a Docker bridge network connected to the WireGuard interface.
  5. This machine becomes an entry point for the newly created cluster which is stored in the cluster config under ~/.config/uncloud on your local machine.

When you add another machine:

$ uc machine add --name hetzner-server root@5.223.45.199
Downloading Uncloud install script: https://raw.githubusercontent.com/psviderski/uncloud/refs/heads/main/scripts/install.sh
 Running Uncloud install script...
 Docker is already installed.
 Linux user and group 'uncloud' created.
 Installing Uncloud binaries...
 Downloading uncloudd binary: https://github.com/psviderski/uncloud/releases/latest/download/uncloudd_linux_amd64.tar.gz
 uncloudd binary installed: /usr/local/bin/uncloudd
 Downloading uninstall script: https://raw.githubusercontent.com/psviderski/uncloud/refs/heads/main/scripts/uninstall.sh
 uncloud-uninstall script installed: /usr/local/bin/uncloud-uninstall
 Systemd unit file created: /etc/systemd/system/uncloud.service
Created symlink /etc/systemd/system/multi-user.target.wants/uncloud.service /etc/systemd/system/uncloud.service.
 Downloading uncloud-corrosion binary: https://github.com/psviderski/corrosion/releases/latest/download/corrosion-x86_64-unknown-linux-gnu.tar.gz
 uncloud-corrosion binary installed: /usr/local/bin/uncloud-corrosion
 Systemd unit file created: /etc/systemd/system/uncloud-corrosion.service
 Starting Uncloud machine daemon (uncloud.service)...
 Uncloud machine daemon started.
 Uncloud installed on the machine successfully! 🎉
Machine "hetzner-server" added to cluster
Waiting for the machine to be ready...

[+] Deploying service caddy 1/1
 Container caddy-d36c on hetzner-server  Started                                                                                                                                     1.0s

Updating cluster domain records in Uncloud DNS to point to machines running caddy service...
[+] Verifying internet access to caddy service 2/2
 Machine hetzner-server (5.223.45.199)  Reachable                                                                                                                                    0.2s
 Machine oracle-vm (152.67.101.197)     Reachable                                                                                                                                    0.1s

DNS records updated to use only the internet-reachable machines running caddy service:
  *.xuw3xd.cluster.uncloud.run  A 152.67.101.197, 5.223.45.199

$ uc machine ls
NAME             STATE   ADDRESS         PUBLIC IP        WIREGUARD ENDPOINTS
oracle-vm        Up      10.210.0.1/24   152.67.101.197   10.0.0.95:51820, 152.67.101.197:51820
hetzner-server   Up      10.210.1.1/24   5.223.45.199     5.223.45.199:51820, [2a01:4ff:2f0:128b::1]:51820
  1. The second machine gets provisioned just like the first. A non-root SSH user will need sudo access.
  2. Allocates a new subnet 10.210.1.0/24 for the second machine and its containers.
  3. Registers the second machine in the cluster state and exchanges WireGuard keys with the first machine.
  4. Both machines establish a WireGuard tunnel between each other, allowing Docker containers connected to the bridge network to communicate directly across machines.
  5. Configures and starts corrosion on the second machine to sync the cluster state.
  6. The second machine is added as an alternative entry point in the cluster config.
  7. If one of the machines goes offline, the other machine can still serve cluster operations.

If one more machine is added, the process repeats with a new subnet. The new machine needs to establish a WireGuard connection with only one of the existing machines. Other machines will learn about it through the shared cluster state and automatically establish a WireGuard tunnel with it.

When you run a service:

$ uc run -p app.example.com:8000/https image/my-app

[+] Running service my-app-1b3b (replicated mode) 1/1
 Container my-app-1b3b-tcex on oracle-vm  Started

my-app-1b3b endpoints:
 https://app.example.com :8000
 https://my-app-1b3b.xuw3xd.cluster.uncloud.run :8000
  1. CLI picks a machine to run your container.
  2. uncloudd that the CLI communicates with uses grpc-proxy to forward the request to the target machine to launch a container there.
  3. uncloudd on the target machine starts the Docker container in the bridge network and stores its info in the cluster's distributed state.
  4. The container gets a cluster-unique IP address from the bridge network (in the 10.210.X.2-254 range) and becomes accessible from other machines in the cluster.
  5. Caddy reverse proxy which runs in global mode on each machine watches the cluster state for new services and updates its configuration to route traffic to the new container.

Look ma, no control plane or master nodes to maintain! Just a simple overlay network and eventually consistent state sync that lets machines work together. Want to check on things or make changes? Connect to any machine either implicitly using the CLI or directly over SSH. They all have the complete cluster state and can control everything. It's like each machine is a full backup of your control plane.

🏗 Project status

Uncloud is currently in active development and is not ready for production use. Features may change significantly and there may be breaking changes between releases.

We'd love your input! Here's how you can contribute:

🙏 Inspiration & Acknowledgements

I'm grateful to the following projects that inspired Uncloud's design and implementation:

Special thanks to the Corrosion project by Fly.io for providing the distributed SQLite database used to share Uncloud's cluster state.

📫 Stay updated

💖 Sponsors

These companies and projects are helping Uncloud with their generous sponsorship and/or services:

Sentry

❤️ Contributors

Thank you @cedws for being the first contributor to Uncloud! 🎉

Join libs.tech

...and unlock some superpowers

GitHub

We won't share your data with anyone else.