user guide

Welcome to the comprehensive user guide for Corral — the unified management platform for virtual machines, pet-pod containers, and local hypervisors.

Backends, contexts, and peers

corral config set-default-backend incus makes unqualified creates use Incus. corral context list|set|get switches Corral's context without mutating kubectl or the Incus CLI; --context is a one-shot override.

Libvirt URIs make remote QEMU a normal backend, for example: corral context set qemu+ssh://hypervisor/system.

A local dashboard can aggregate an in-cluster Corral without a local kubeconfig: corral peer add homelab https://corral.example.ts.net. Console routing tries the VM's advertised direct address first and relays through the peer only when direct access is unavailable.

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1. Overview & Architecture

Corral brings together diverse virtualization and container workloads under a single interface, CLI, and Tailscale network.

flowchart TD
    User([User / CLI / Web UI]) --> Corral[Corral Core]

    subgraph Backends
        Corral --> QEMU[QEMU / KVM Local]
        Corral --> KubeVirt[KubeVirt / Kubernetes]
        Corral --> CT[Pet-Pod CT / K8s]
        Corral --> Incus[Incus / LXC and VMs]
        Corral --> Libvirt[libvirt local or SSH URI]
        Corral --> Peer[Remote Corral peer]
    end

    subgraph Access Layer
        QEMU --> Tailnet[Tailscale Tailnet]
        KubeVirt --> Tailnet
        CT --> Tailnet
        Incus --> Tailnet
        Libvirt --> Tailnet
        Peer --> Tailnet
    end

Supported Compute Backends

Backend	Scope	Tech Stack	Use Case
QEMU	Local Host	QEMU / KVM + systemd	Fast, local ephemeral or dev VMs on your workstation
KubeVirt	Cluster	KubeVirt + Kubernetes	Production VMs with live migration, PVC storage, and scaling
Container (CT)	Cluster	Kubernetes Pod + PVC	"Pet Pods" — persistent Linux containers (Distrobox on K8s)
Incus	Local or remote	Incus remote	Containers and VMs managed through existing Incus trust
libvirt	Local or remote	libvirt URI / OpenSSH	Existing domains and remote QEMU hypervisors

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2. Interactive Interfaces

Web Dashboard

Access the Proxmox-style Web UI at http://localhost:8006 or via corral web.

Features:

• Datacenter Tree: Navigate through all VMs, CTs, and Incus instances across local and cluster nodes.
• Live CPU & Memory Sparklines: Real-time load monitoring per VM.
• Tag Filtering: Filter instances by custom tags (prod, dev, desktop).
• Mobile Responsive: Manage your VM fleet from your mobile browser.
• Theme & Branding: Customize accent colours, header branding, and inject custom CSS — via CLI flags, config file, or the built-in Settings page.

Theme & Branding

Corral's web UI accent colour, header branding, and custom CSS are fully customizable — no source-code changes needed.

CLI flags (highest priority, override everything):

corral web --accent \"#3b82f6\" --brand-title \"My Lab\" --brand-emoji \"⚡\" --brand-subtitle \"Engineering\"

Config file (~/.config/corral/config.yaml, loaded on startup):

web:
  accent: \"#22c55e\"        # CSS hex colour
  accent_2: \"#16a34a\"      # hover/active variant
  brand_title: \"My Lab\"
  brand_emoji: \"⚡\"
  brand_subtitle: \"Engineering\"
  custom_css: |
    .btn.primary { border-radius: 20px; }
    .card { background: var(--panel-2); }

Settings page (web UI → Settings in the sidebar):

• Colour picker with preset swatches (Orange, Blue, Green, Purple, Red, Amber)
• Brand title, emoji, and subtitle fields with live header preview
• Custom CSS textarea that injects styles immediately as you type
• Save button persists to config.yaml

Precedence: CLI flags > config.yaml > built-in defaults (🤠 Corral, orange accent).

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Terminal UI (TUI)

Launch the interactive Bubble Tea TUI by running corral with no arguments (or explore in demo mode with corral --demo).

The left side is a unified, searchable fleet. Wide terminals add a details pane with canonical ID, backend/context, placement, address, resources, and available operations. Failed remotes appear as partial-fleet warnings without hiding healthy instances.

TUI keyboard shortcuts and features

• / fuzzy-searches names, canonical IDs, backends, contexts, nodes, and IPs.
• Tab, [ and ] cycle between the complete fleet and named contexts.
• Enter opens a capability-aware action menu; unsupported operations are absent rather than failing after selection.
• s and x quickly start or stop the selected VM; r refreshes every backend.
• d runs scoped QEMU, KubeVirt, Incus, and libvirt diagnostics.
• ? opens the in-app command deck.
• QEMU, KubeVirt, Incus, libvirt, and pet-pod CTs share the inventory without losing their backend-specific capabilities.

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3. Core Feature Walkthrough

1. Instance Lifecycle Management

Create and manage instances across any backend with identical commands:

# Create local QEMU VM
corral create dev-vm --iso https://example.com/ubuntu.iso --disk 40G

# Create KubeVirt cluster VM
corral create prod-vm --kubevirt --image fedora

# Create on an existing Incus remote
corral create fast-ct --backend incus --context lab --image images:ubuntu/22.04

# Universal operations
corral start dev-vm
corral stop dev-vm
corral delete dev-vm

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2. Remote Access: VNC, RDP & TTY

Corral provides single-command remote access to guest displays and shells:

In-Browser & Local VNC

• VNC Display: corral viewer <vm-name> opens a VNC session. In the Web UI, noVNC provides zero-install browser display access.
• Interactive TTY / SSH: corral ssh <vm-name> or corral tty <ct-name> connects your terminal directly into guest shell namespaces (via SSH, virtctl console, or incus exec).

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3. Bootable Container Images (bootc)

Boot containers directly as VMs using the bootc plugin:

corral plugin install bootc
corral bootc create my-node --image quay.io/centos-bootc/centos-bootc:stream9

• Builds a bootable OS disk on-cluster using bootc install to-disk.
• Upgrade guest OS images using corral bootc upgrade <vm-name>.

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4. Proxmox VE API Compatibility Layer

Corral includes a Proxmox VE REST API emulation layer (/api2/json/...), allowing Terraform (bpg/proxmox), Ansible, and Proxmoxer tools to manage KubeVirt and Incus instances natively.

corral plugin install proxmox
corral proxmox serve --addr :8006

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5. Plugin Marketplace

Expand Corral with lightweight marketplace plugins:

# Browse marketplace
corral plugin search

# Installed plugins
corral plugin list

# Plugin management
corral plugin install <name>
corral plugin remove <name>

Available Plugins:

• bootc: Bootable container image VM builder.
• proxmox: Proxmox VE REST API compatibility server.
• backup: S3/R2 VM disk backup & restore.
• snapsched: Automated VM snapshot schedules with retention rules.
• schedule: VM autostart and shutdown cron windows.
• gpu: GPU / PCI passthrough device plugin discovery.
• windows: First-class Windows VM creation (UEFI, TPM, virtio drivers).
• vdi: Virtual Desktop Infrastructure desktop pools.

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4. Diagnostics & Troubleshooting

Run corral doctor to diagnose cluster capabilities, hypervisor support, and storage drivers:

corral doctor

In a multi-context setup it diagnoses every configured QEMU, KubeVirt, Incus, and libvirt target. Use corral doctor --context NAME for one target. The complete capability matrix and direct-versus-relayed networking behavior are documented in backend-support.md.

✓ KubeVirt installed (v1.8.2)
✓ CDI containerized data importer available
✓ Default StorageClass supports volume expansion
✓ VolumeSnapshotClass available for backups
✓ QEMU KVM hardware acceleration (/dev/kvm) accessible
✓ Incus daemon socket (/var/lib/incus/unix.socket) active

Reproducible screenshots

Documentation captures use the real built-in demo fleet. They are automated for both Chromium and the Bubble Tea TUI:

npm install --prefix e2e
node scripts/capture-docs.mjs docs/screenshots/generated

The same command can target the TunaOS site checkout: node scripts/capture-docs.mjs ../docs/static/img/screenshots/corral.