kvm: provide solution if user doesn't belong to libvirt group

[prezha]

fixes #5617
fixes #10070

for kvm driver, as described in original issues, if user does not belong to libvirt group, we fail with a generic confusing message
here we check that and provide a more descriptive solution message if not

example (after)

❯ id
uid=1000(prezha) gid=100(users) groups=100(users),459(docker)

❯ minikube start --driver=kvm2
😄  minikube v1.18.0 on Opensuse-Tumbleweed
✨  Using the kvm2 driver based on user configuration

🚫  Exiting due to PR_KVM_USER_PERMISSION: libvirt group membership check failed:
user is not a member of the appropriate libvirt group
💡  Suggestion: Ensure that you are a member of the appropriate libvirt group (remember to relogin for group changes to take effect!)
📘  Documentation: https://minikube.sigs.k8s.io/docs/reference/drivers/kvm2/
🍿  Related issues:
    ▪ https://github.com/kubernetes/minikube/issues/5617
    ▪ https://github.com/kubernetes/minikube/issues/10070

❯ minikube start --driver=kvm2 --alsologtostderr -v=9
I0304 01:28:48.201151    1629 out.go:239] Setting OutFile to fd 1 ...
I0304 01:28:48.201206    1629 out.go:291] isatty.IsTerminal(1) = true
I0304 01:28:48.201211    1629 out.go:252] Setting ErrFile to fd 2...
I0304 01:28:48.201215    1629 out.go:291] isatty.IsTerminal(2) = true
I0304 01:28:48.201284    1629 root.go:308] Updating PATH: /home/prezha/.minikube/bin
I0304 01:28:48.201437    1629 out.go:246] Setting JSON to false
I0304 01:28:48.225822    1629 start.go:108] hostinfo: {"hostname":"codex.triplepoint.tech","uptime":7886,"bootTime":1614813443,"procs":416,"os":"linux","platform":"opensuse-tumbleweed","platformFamily":"","platformVersion":"","kernelVersion":"5.10.16-1-default","kernelArch":"x86_64","virtualizationSystem":"kvm","virtualizationRole":"host","hostId":"8fbb1ced-553b-443c-a3a1-fd6724e8ce90"}
I0304 01:28:48.226056    1629 start.go:118] virtualization: kvm host
I0304 01:28:48.237151    1629 out.go:129] 😄  minikube v1.18.0 on Opensuse-Tumbleweed
😄  minikube v1.18.0 on Opensuse-Tumbleweed
I0304 01:28:48.237467    1629 notify.go:126] Checking for updates...
I0304 01:28:48.237777    1629 driver.go:323] Setting default libvirt URI to qemu:///system
I0304 01:28:48.243203    1629 out.go:129] ✨  Using the kvm2 driver based on user configuration
✨  Using the kvm2 driver based on user configuration
I0304 01:28:48.243272    1629 start.go:276] selected driver: kvm2
I0304 01:28:48.243297    1629 start.go:718] validating driver "kvm2" against <nil>
I0304 01:28:48.243335    1629 start.go:729] status for kvm2: {Installed:true Healthy:false Running:true NeedsImprovement:false Error:libvirt group membership check failed:
user is not a member of the appropriate libvirt group Reason:PR_KVM_USER_PERMISSION Fix:Check that libvirtd is properly installed and that you are a member of the appropriate libvirt group (remember to relogin for group changes to take effect!) Doc:https://minikube.sigs.k8s.io/docs/reference/drivers/kvm2/}
I0304 01:28:48.246662    1629 out.go:129]

W0304 01:28:48.246878    1629 out.go:191] 🚫  Exiting due to PR_KVM_USER_PERMISSION: libvirt group membership check failed:
user is not a member of the appropriate libvirt group
🚫  Exiting due to PR_KVM_USER_PERMISSION: libvirt group membership check failed:
user is not a member of the appropriate libvirt group
W0304 01:28:48.247126    1629 out.go:191] 💡  Suggestion: Ensure that you are a member of the appropriate libvirt group (remember to relogin for group changes to take effect!)
💡  Suggestion: Ensure that you are a member of the appropriate libvirt group (remember to relogin for group changes to take effect!)
W0304 01:28:48.247252    1629 out.go:191] 📘  Documentation: https://minikube.sigs.k8s.io/docs/reference/drivers/kvm2/
📘  Documentation: https://minikube.sigs.k8s.io/docs/reference/drivers/kvm2/
W0304 01:28:48.247350    1629 out.go:191] 🍿  Related issues:
🍿  Related issues:
W0304 01:28:48.247497    1629 out.go:191]     ▪ https://github.com/kubernetes/minikube/issues/5617
    ▪ https://github.com/kubernetes/minikube/issues/5617
W0304 01:28:48.247615    1629 out.go:191]     ▪ https://github.com/kubernetes/minikube/issues/10070
    ▪ https://github.com/kubernetes/minikube/issues/10070
I0304 01:28:48.253543    1629 out.go:129]

[medyagh]

/ok-to-test

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[offlinehacker]

This check breaks if using libvirt over tcp. I am running libvirt inside docker container and this breaks minikube. It also kinda does not make sense to force this check.

[prezha]

@offlinehacker i think this check has been there for a while now and was asked by users with an idea to prevent a number of issues (eg, #5617)

for your specific setup, did you try --force flag (it should emit an error but not exit then)?