Uncloud skill

Uncloud Cluster Management

Reference for the uc CLI — a decentralised self-hosting platform using Docker containers, WireGuard mesh networking, and Caddy reverse proxy.

Core Concepts

• No central control plane — all machines are equal peers connected by WireGuard
• Caddy runs as a global service on every machine; auto-obtains TLS from Let's Encrypt
• Overlay network — services communicate via 10.210.0.0/16 by default; DNS provided inside the mesh
• Caddyfile is autogenerated — never edit it directly; use x-caddy / --caddyfile instead

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CLI Quick Reference

Machines

Command	Purpose
uc machine init user@host	Bootstrap first machine / new cluster
uc machine add user@host	Join machine to existing cluster
uc machine ls	List machines
uc machine update NAME --public-ip IP	Update public IP for ingress
uc machine rm NAME	Remove machine

Key init flags: --name, --network 10.210.0.0/16, --no-caddy, --no-dns, --public-ip auto\|IP\|none

Services

Command	Purpose
uc service ls / uc ls	List services
uc service run IMAGE	Run a single container service
uc deploy	Deploy from compose.yaml
uc scale SERVICE N	Set replica count
uc service logs SERVICE	View logs
uc service exec SERVICE	Shell into container
uc service inspect SERVICE	Detailed info
uc service rm SERVICE	Remove service (keeps named volumes)
uc ps	All containers across cluster

Images

uc image push myapp:latest                    # Push local image to all machines
uc image push myapp:latest -m machine1,machine2  # Push to specific machines
uc images                                     # List images in cluster

Volumes

uc volume ls                  # All volumes
uc volume ls -m machine1      # On specific machine
uc volume create NAME -m MACHINE
uc volume rm NAME

Caddy

uc caddy config    # Show current generated Caddyfile (read-only)
uc caddy deploy    # Deploy/upgrade Caddy across cluster

DNS & Context

uc dns show        # Show reserved *.uncld.dev domain
uc dns reserve     # Reserve a new domain
uc ctx ls          # List cluster contexts
uc ctx use prod    # Switch context

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Port Publishing

HTTP/HTTPS (via Caddy reverse proxy)

-p [hostname:]container_port[/protocol]

Example	Meaning
-p 8080/https	HTTPS with auto service-name.cluster-domain hostname
-p app.example.com:8080/https	HTTPS with custom hostname
-p 8080/http	HTTP only, no TLS

TCP/UDP (host-bound, bypasses Caddy)

-p [host_ip:]host_port:container_port[/protocol]@host

Example	Meaning
-p 5432:5432@host	TCP 5432 on all interfaces
-p 127.0.0.1:5432:5432@host	TCP 5432 loopback only
-p 53:5353/udp@host	UDP

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Compose File Extensions

Uncloud adds these extensions on top of Docker Compose:

x-ports — publish ports with domains

services:
  app:
    image: app:latest
    x-ports:
      - example.com:8000/https
      - www.example.com:8000/https
      - api.example.com:9000/https

x-caddy — custom Caddy config for service

services:
  app:
    image: app:latest
    x-caddy: |
      example.com {
        redir https://www.example.com{uri} permanent
      }
      www.example.com {
        reverse_proxy {{upstreams 8000}} {
          import common_proxy
        }
        basic_auth /admin/* {
          admin $2a$14$...
        }
      }

Template functions available inside x-caddy:

• {{upstreams [service] [port]}} — healthy container IPs
• {{.Name}} — service name
• {{.Upstreams}} — map of all services → IPs

x-machines — placement constraints

services:
  db:
    image: postgres:18
    x-machines: db-machine          # Single machine name
  app:
    image: app:latest
    x-machines:
      - machine-1
      - machine-2

Full multi-service example

services:
  api:
    build: ./api
    x-ports:
      - api.example.com:3000/https
    environment:
      DATABASE_URL: postgres://db:5432/mydb

  web:
    build: ./web
    x-ports:
      - example.com:8000/https
      - www.example.com:8000/https
    environment:
      API_URL: http://api:3000

  db:
    image: postgres:18
    environment:
      POSTGRES_PASSWORD: ${DB_PASSWORD}
    volumes:
      - db-data:/var/lib/postgresql/data
    x-machines: db-machine

volumes:
  db-data:

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Routing to External (Non-Cluster) Devices

To expose an external device (e.g. BMC, NAS, router UI) via Caddy without running a real container:

1. Create a Caddyfile snippet (e.g. ~/device.caddyfile):

https://device.example.com {
    reverse_proxy https://192.168.1.x {
        transport http {
            tls_insecure_skip_verify   # needed for self-signed BMC certs
        }
    }
    log
}

For plaintext upstream: reverse_proxy http://192.168.1.x:port

2. Register as a named service with no-op container:

uc service run \
  --name device-bmc \
  --caddyfile ~/device.caddyfile \
  registry.k8s.io/pause:3.9

pause is a minimal no-op container — it does nothing, but gives Uncloud a service entry to attach the Caddyfile to.

3. Verify:

uc caddy config   # device.example.com block should appear

--caddyfile cannot be combined with non-@host published ports.

DNS tip: A wildcard record (*.yourdomain.com → cluster-public-ip) means any new subdomain works immediately — no DNS change needed per service.

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Service DNS (Internal)

Services inside the cluster resolve each other by name:

DNS name	Resolves to
service-name	Any healthy container
service-name.internal	Same
rr.service-name.internal	Round-robin
nearest.service-name.internal	Machine-local first

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Scaling & Global Services

uc scale web 5    # 5 replicas (spread across machines)
uc scale web 1    # Scale down

services:
  caddy:
    deploy:
      mode: global   # One container on every machine

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Image Tag Templates (in compose.yaml)

image: myapp:{{gitdate "20060102"}}.{{gitsha 7}}
image: myapp:{{gitsha 7}}.${GITHUB_RUN_ID:-local}

Function	Output
{{gitsha N}}	First N chars of commit SHA
{{gitdate "format"}}	Git commit date in Go format
{{date "format"}}	Current date

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Common Workflows

Deploy from source:

uc deploy                          # Build + push + deploy
uc build --push && uc deploy --no-build   # Separate steps

Inspect a service:

uc inspect web
uc logs -f web
uc logs --since 1h web
uc exec web                        # Opens shell
uc exec web /bin/sh -c "env"       # Run specific command

Zero-downtime deploys happen automatically; Uncloud waits for health checks before terminating old containers.

Force recreate:

uc deploy --recreate

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Common Mistakes

Mistake	Fix
Editing the Caddyfile directly	Use x-caddy in compose or --caddyfile on uc service run
Proxying an HTTPS upstream with self-signed cert	Add transport http { tls_insecure_skip_verify }
uc caddy config shows no user-defined blocks	Caddy admin socket unreachable — check uc inspect caddy and uc logs caddy
Service can't reach external LAN IP from container	Verify Caddy container's host can route to target network
Volumes lost after uc service rm	Named volumes persist; only anonymous volumes are auto-removed