Update hypervisor default from "virtualbox" to best-available

[staticdev]

The exact command to reproduce the issue: minikube start

The full output of the command that failed:

😄 minikube v1.2.0 on linux (amd64)
💿 Downloading Minikube ISO ...
129.33 MB / 129.33 MB [============================================] 100.00% 0s
🔥 Creating virtualbox VM (CPUs=2, Memory=2048MB, Disk=20000MB) ...
E0626 20:40:20.432969 26803 start.go:559] StartHost: create: precreate: VBoxManage not found. Make sure VirtualBox is installed and VBoxManage is in the path

💣 Unable to start VM
❌ Error: [VBOX_NOT_FOUND] create: precreate: VBoxManage not found. Make sure VirtualBox is installed and VBoxManage is in the path
💡 Advice: Install VirtualBox, ensure that VBoxManage is executable and in path, or select an alternative value for --vm-driver
📘 Documentation: https://www.virtualbox.org/wiki/Downloads
⁉️ Related issues:
▪ #3784
▪ #3776

😿 If the above advice does not help, please let us know:
👉 https://github.com/kubernetes/minikube/issues/new

The output of the minikube logs command:

💣 api load: filestore: Docker machine "minikube" does not exist. Use "docker-machine ls" to list machines. Use "docker-machine create" to add a new one.

😿 Sorry that minikube crashed. If this was unexpected, we would love to hear from you:
👉 https://github.com/kubernetes/minikube/issues/new

The operating system version: Ubuntu 19.04

Comments: Documentation on README says: Requires either the kvm2 driver (recommended), or VirtualBox. I have kvm2 installed.. so it shouldn't give an error. I think even if I didn't have kvm, it should try driver=none by default instead of giving error.

[sharifelgamal]

Are you sure virtualbox is installed on your machine? What happens if you just try to call VBoxManage?

[staticdev]

@sharifelgamal virtualbox is NOT installed, but kvm2 is. My point is.. If the documentation recommends kvm2 for Linux, minikube start shouldn't have default virtualbox! It should at least have a fallback (as I said in the comments above).

[sharifelgamal]

That's totally my bad for missing the comment at the bottom. VirtualBox has always been the default driver since it's totally cross-platform and is mentioned as the default in the same documentation where we also recommend kvm2 for linux. You can also set kvm2 to be your default driver in the config as documented here.

[staticdev]

@sharifelgamal that is totally ok. This issue could be an enhancement proposal for a smoother experience with minikube start. It tries the default, if it is not found, instead of error it tries kvm2, if not found it tries none (example on Linux but could use same logic for other OS).

Sidenote: The none try should check if it is sudo. If not gives the suggestion of running sudo or installing a VM driver.

[sharifelgamal]

We have added the error message when a user doesn't use sudo for the none driver, it will be included in the next release.

As far as auto-picking VM drivers, I think adding that complexity to the code doesn't really add much, the user is generally aware of which VM they want to use ahead of time.

What do you think @tstromberg?

[staticdev]

I think this is a very strong statement: "User is generally aware of which VM they want to use ahead of time". Many people (including me) start learning k8s by downloading minikube. I have co-workers which are developers that uses minikube to see how an application behaves in a cluster, and they have virtually no knowledge about VMs and underlying infrastructure.

[afbjorklund]

Unfortunately I think it is the documentation that is wrong, VirtualBox is still the default driver and we haven’t found a good way to bundle kvm2 yet (it is on the roadmap)

[sharifelgamal]

VirtualBox is still documented as the default driver, kvm2 is just the recommended one.

[staticdev]

I feel that there is some degree of disagreement coming from the personal taste of minikube developers, which is totally understandable. However, this type of misalignment causes confusion and misinformation to end users. It's up for the team to came to an agreement and choose the best strategy to communicate though the error messages, CLI command help and documentation.

I've been using minikube for some months now and my experience with kvm2 on Linux is better than virtualbox in terms of performance and network issues.

[afbjorklund]

More a question of whether the documentation should reflect where we want to go or where we are ?
Things like #4391 and #4555 need to be fixed, if kvm2 (libvirt) is supposed to work out-of-the-box...

The ultimate goal is to have minikube use the (so called) "native" virtualization, for each platform.
This is further complicated by the use of docker machine, which is still a third-party - even if modified.

I don't think we should use the none driver by default, it is very different (and not recommended).
Our current again(!) recommendation is to start a VM in that case, and then run none driver on it.

Eventually we will have a situation where it is ok to start minikube in "VM-free" mode (see #4389)
But at the moment it really does have all the drawbacks listed in the documentation for the none driver.

[afbjorklund]

@blueelvis : are we good to go, on recommending the hyperv driver for Windows 10+ ?

#4846 #4783

Or do we need some outstanding items like CI support still, that is blocking that change ?

#3591 @medyagh

[blueelvis]

@afbjorklund - I am waiting for the upcoming release where the bug of stopping the minikube cluster on Hyper-V is fixed. The bugs which you have mentioned are still in my mind (Hoping to finish them this weekend).

And yes, going forward, I would recommend Hyper-V for Windows 10+ and we do require the CI support for the long run. It is not a blocking change as from my experience with minikube and Hyper-V, its pretty stable (Except shutting down...).

-Pranav