faq.md

Frequently Asked Questions (FAQ)

Q: What hypervisors does ops currently support?

A: Currently, nanos can run on both qemu and xen QEMU. We are obviously open to adding more support for other various hypervisors but there are considerations to be had.

Also - Nanos runs on Google Cloud && AWS.

Q: What version of qemu is best?

A: We track latest qemu in homebrew as we have found issues before. The latest qemu release is currently 6.0.X. If you don't have that release try to install from brew:

brew tap nanovms/homebrew-qemu
brew install nanovms/homebrew-qemu/qemu

Q: Can I contribute?

A: Sure! We accept pull requests and if you have prior kernel experience please get in touch with NanoVMs - they might even want to pay you.

Q: What artifact does ops produce?

A: ops builds a disk image artifact that you can find in ~/.ops/images. . You can get a list of all your images via:

ops image list -t onprem

This disk image is ran by qemu to execute your application.

Q: Can I run ops inside a container? {#container}

A: Yes, it is possible to run ops within a container such as docker. Although, it is NOT recommended to do so, especially for production environments. You will likely run into performance related issues.

Q: What if I need to 'shell out'?

A: We consider this an anti-pattern of software development and a scourge on the software ecosystem. It is advised to utilize your native language API and libraries to achieve the task instead.

Q: What about the filesystem?

A: Nanos currently makes use of the TFS filesystem and can run databases and other things through the POSIX api you all know.

Q: How do I run ops on a cloud provider with bridged networking?

A: We do not suggest running ops on a cloud provider on top of linux. We suggest using the native way of provisioning your unikernels so they run by themselves standalone and you won't have do any network configuration.

Please see the following cloud documentation for whichever cloud provider you wish to run on:

• Google Cloud Integration
• AWS Integration
• Digital Ocean
• Vultr

Q: My ssh connection gets terminated while running ops net setup {#ssh-terminate}

A: This is only necessary if you wish to create your own bridges and attach tap interfaces to them. It's not a task we suggest most people do though.

Q: Does this work with kubernetes?

A: This can work with kubernetes but kubernetes is a container orchestrator and is typically deployed on top of an existing virtual machine whereas the intention for these are to run as virtual machines. Further, kubernetes has very serious security issues that should be considered such as sharing a kernel amongst multiple tenants.

Please see the documentation for running Nanos under kubernetes.

Q: Is there an API?

Yes, if you are coding in Go you can use the API found at https://pkg.go.dev/github.com/nanovms/ops/lepton .

If you are looking for a web-accessible API Nanos C2 has you covered.

Q: How can I tell if I'm running inside Nanos at runtime?

You can use the Uname syscall and extract the sysname from it:

package main

import (
	"fmt"
	"syscall"
)

func int8ToStr(arr []int8) string {
	b := make([]byte, 0, len(arr))
	for _, v := range arr {
		if v == 0x00 {
			break
		}
		b = append(b, byte(v))
	}
	return string(b)
}

func main() {
	utsname := syscall.Utsname{}
	err := syscall.Uname(&utsname)
	if err != nil {
		fmt.Println(err)
	}

	fmt.Printf("%+v\n", int8ToStr(utsname.Sysname[:]))
}