Minikube: none driver: minikube shouldn't write binaries to /usr/bin

[tstromberg]

With the none driver, minikube will overwrite the following system paths:

• /usr/bin/kubeadm - Updated to match the exact version of Kubernetes selected
• /usr/bin/kubectl - Updated to match the exact version of Kubernetes selected

Basically, anywhere else is better, but to write directly to /usr/bin feels yucky. It'd be nicer to write the binaries somewhere else, preferably but not necessarily versioned. For instance:

$XDG_CACHE_HOME/minikube/binaries/kubeadm-v1.13.0

Or:

/usr/local/minikube/kubeadm-v1.13.0

[afbjorklund]

I think it is perfectly reasonable to install kubeadm to the default /usr/bin location.
The same thing happens, if you install it from an .rpm and a .deb for instance ?

https://kubernetes.io/docs/setup/independent/install-kubeadm/#installing-kubeadm-kubelet-and-kubectl

After all, the VM you give to minikube is dedicated to running kubernetes on.
You are not giving it something important - like directly on your laptop, right ? ;-)

https://github.com/kubernetes/minikube/blob/master/docs/vmdriver-none.md

[afbjorklund]

Could install to /usr/local/bin, but I'm not sure that would help anything.

[afbjorklund]

With the none driver, minikube will overwrite the following system paths:

• /usr/bin/kubeadm - Updated to match the exact version of Kubernetes selected
• /usr/bin/kubectl - Updated to match the exact version of Kubernetes selected

You probably mean "/usr/bin/kubelet" here ? We don't install kubectl - yet.

[tstromberg]

Using /usr/bin violates both user expectations and the LSB/FHS standards: https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch04s09.html

The main user expectation violated is that we may be overwriting system binaries.

Storing files in /usr/bin also conflicts with the goal of reducing/removing usage of 'minikube' by the root user: https://github.com/kubernetes/minikube/issues/3138

[afbjorklund]

@tstromberg : I guess I am still thinking about the old/existing implementation, when you run sudo -E minikube start --vm-driver=none locally on your dedicated VM - rather than the new version of actually running it on the same machine as the 'kubectl` like your laptop or so. When running locally, it makes sense to not overwrite system binaries and to run minikube without root (by it using sudo where it is needed).

Maybe we could use the binaries straight off the cache, rather than copying them to a temp location ?
~/.minikube/cache/v1.13.0/kubeadm vs ~/.cache/minikube/binaries/kubeadm-v1.13.0

[MatejLach]

Is there a workaround for now?

[afbjorklund]

Suppose you could store the old files, and then restore/reinstall them after minikube ?

[tstromberg]

I did some prototyping where the binaries are stored in /data/minikube, and it worked great. The plus side is that it's persistent across reboots, which speeds up minikube.

[medyagh]

I also think having it in /usr/bin is a bad idea, since many corporates deny access to that folder but they allow /usr/loca/bin

[afbjorklund]

Normally this is because /usr is handled by the package manager, while /usr/local is not.

Note that for the current release, we could run them right off the cache (now made executable)
This was originally intended for kubectl, but ended up the same for kubeadm and kubelet too:

$ ~/.minikube/cache/v1.15.0/kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.0", GitCommit:"e8462b5b5dc2584fdcd18e6bcfe9f1e4d970a529", GitTreeState:"clean", BuildDate:"2019-06-19T16:37:41Z", GoVersion:"go1.12.5", Compiler:"gc", Platform:"linux/amd64"}
$ ~/.minikube/cache/v1.15.0/kubelet --version
Kubernetes v1.15.0

It's not in the PATH though, and there are some changes needed to the created startup scripts:

https://github.com/kubernetes/minikube/blob/master/pkg/minikube/bootstrapper/kubeadm/kubeadm.go

https://github.com/kubernetes/minikube/blob/master/pkg/minikube/bootstrapper/kubeadm/templates.go

[rzr]

well do you agree that the minikube.deb package could write to /usr/bin
as long as there is a conflict with kubeadm.deb

grep -i Conflicts  ./installers/linux/deb/*deb*/DEBIAN/control

Is that correct ? I can open a PR to fix this

The nicer way would be to use alternatives links.

BTW, way isnt minikube.deb in same repo as other k8 debs ?

[afbjorklund]

The minikube.deb will install /usr/bin/minikube, there should be no conflict ?

For the none driver, we will _either_ use ~/.minikube/cache or the _other_ deb.
Currently we install /usr/bin/kubeadm, but that's a bug. Specifically, this one.

So far, minikube has just pulled the static binaries - and installed them to /usr/bin.
That _should_ probably have been /usr/local/bin, but that's not ideal either...

https://storage.googleapis.com/kubernetes-release/release/v1.15.1/bin/linux/amd64/kubeadm

The "other" kubeadm.deb would be this one: kubeadm_1.15.1-00_amd64_*.deb
But we haven't really had a policy for installing minikube with apt and yum just yet.

https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/

---

Theoretically it _could_ use the deb and rpm packages - on the supported platforms ?
This is similar to how the docker installation works, when using https://get.docker.com

And then continue to use the static binaries, on non-ubuntu and non-centos distros.
For instance when using our standard minikube distribution, i.e. the minikube.iso

It's all for show anyway, since it is the same binary packaged in several multiple ways.

3d42441ae177826f1181e559cd2a729464ca8efadef196cfa0e8053a615333b5  kubeadm
3d42441ae177826f1181e559cd2a729464ca8efadef196cfa0e8053a615333b5  usr/bin/kubeadm

One benefit with our approach is that we can have multiple versions - at the same time.

[afbjorklund]

BTW, way isnt minikube.deb in same repo as other k8 debs ?

Sadly, not yet. There's some work under way, to improve this.

3110 #4716

[tstromberg]

Fix merged to head.