Skip to main content

Documentation Index

Fetch the complete documentation index at: https://mintlify.com/stratosphere-ve/ozone/llms.txt

Use this file to discover all available pages before exploring further.

Ozone is Stratosphere’s open-source Go library for managing QEMU virtual machines. It abstracts the complexity of launching and stopping qemu-system-x86_64 processes and provides a structured, JSON-driven configuration model so that VM definitions live in version-controllable files rather than ad-hoc shell scripts. Whether you are building an internal cloud platform or automating local development environments, Ozone gives you a clean Go API to describe, start, and stop virtual machines without writing raw QEMU command lines by hand.

​
Packages

Ozone is organised into two focused packages that can be used independently or together. qemu — Lifecycle management. Contains Start() and Stop() functions. Start() prompts for a VM name via stdin, calls vmparser.VMParser to load the config, and launches qemu-system-x86_64 with the q35 machine type and a QMP control socket on tcp:127.0.0.1:4444. Stop() runs a system_powerdown command to halt the guest. vmparser — Configuration parsing and writing. Reads and writes JSON VM definition files stored under a vms/ directory. Exposes both whole-VM accessors (VMParser, GetVM) and fine-grained, strongly-typed accessors for each resource group: CPU, memory, network, and disk.

​
Explore Ozone

Quickstart

Install Ozone, write your first VM config, and boot a virtual machine in minutes.

VM Configuration

Learn the full JSON schema for defining CPU, memory, network, and disk resources.

QEMU Management

Understand how qemu.Start() and qemu.Stop() control the VM lifecycle.

API Reference

Browse every exported function and type in the qemu and vmparser packages.

​
Key Features

  • q35 machine type — VMs are launched with -machine q35, providing a modern PCIe-based chipset suitable for most guest operating systems.
  • QMP over TCP — Ozone opens a QEMU Machine Protocol socket at tcp:127.0.0.1:4444 (server,nowait), enabling programmatic VM control without attaching to a console.
  • JSON VM definitions — Each VM is described by a single JSON file under the vms/ directory (e.g. vms/myvm.json), keeping configuration declarative and diff-friendly.
  • Strongly-typed accessors — The vmparser package exposes individual getter functions (GetCPUCores, GetMemorySizeMB, GetMAC, GetDiskPath, …) so callers never have to navigate raw map[string]interface{} values.
  • Selective config writers — Per-resource writer functions (VMParserWriterCPU, VMParserWriterMemory, VMParserWriterNetwork, VMParserWriterDisk, VMParserWriterInfo) update only the relevant section of a config file while preserving all other fields.
  • Zero external dependencies — The go.mod declares only the Go standard library, making Ozone straightforward to vendor or embed.

​
How It Works

The diagram below shows the relationship between a VM config file, the vmparser package, and qemu.Start(). 
vms/myvm.json
      │
      │  vmparser.VMParser("myvm")
      ▼
  vmparser.VM  ──────────────────► qemu.Start()
  (CPU / Memory / Network / Disk)       │
                                        │  exec.Command(
                                        │    "qemu-system-x86_64",
                                        │    "-machine", "q35",
                                        │    "-smp", "4",
                                        │    "-qmp", "tcp:127.0.0.1:4444,server,nowait",
                                        │    ...
                                        │  )
                                        ▼
                                  Running QEMU VM
Start() reads the VM name interactively from stdin, calls vmparser.VMParser to load the config from vms/<vmname>.json, and then launches the QEMU process via exec.Command. Stop() runs system_powerdown to halt the guest.
qemu.Start() reads the VM name from standard input using fmt.Scanln, making it interactive by design. See the Quickstart for a full walkthrough, and the API Reference if you need to call vmparser.VMParser directly for non-interactive or programmatic use.

Build docs developers (and LLMs) love

Get started for freeTalk to us