Compose stack

The stack

One file defines a VXLAN network, a database VM, and three web VMs behind a virtual IP. The web VMs wait for the database to report healthy, spread across hosts, and never share a host with it.

name: "web-app"

networks:
  frontend:
    type: "vxlan"
    vni: 1000
    subnet: "10.0.100.0/24"
    host-isolation: true

vms:
  base-vm:
    image: "ubuntu"
    cpu: 2
    memory: "4G"
    replicas: 0              # a template other VMs extend

  db:
    extends: "base-vm"
    cpu: 4
    memory: "8G"
    disks:
      root: "20G"
      data:
        size: "100G"
    network:
      - name: "frontend"
    placement:
      anti-affinity: ["web"]
    restart:
      condition: "on-failure"

  web:
    extends: "base-vm"
    replicas: 3
    network:
      - name: "frontend"
    placement:
      anti-affinity: ["db"]
      spread: true
      max-per-node: 1
    depends-on:
      db:
        condition: vm_healthy
    loadbalancer:
      vip: "10.0.100.50/24"
      ports:
        - listen: 80
          target: 80
    healthcheck:
      type: "http"
      target: "http://localhost:80/"
      interval: "10s"
      retries: 3
      action: "restart"

Deploy and manage

lv compose up                    # deploy litevirt-compose.yaml
lv compose up -f mystack.yaml    # deploy a specific file
lv compose diff                  # preview what would change
lv compose ps                    # list the stack's VMs
lv compose down                  # tear the stack down

After editing the file, lv compose diff shows what would change and lv compose up applies it. The Compose guide covers every key, including update strategy, backups, and PCI devices.