Support arm64

[vielmetti]

Device under test is a Packet c1.large.arm 96-core arm64 machine running Ubuntu 18.04.

ed@ed-2a-bcc-llvm:~$ go version
go version go1.11.2 linux/arm64
ed@ed-2a-bcc-llvm:~$ go get sigs.k8s.io/kind
ed@ed-2a-bcc-llvm:~$ go/bin/kind create cluster
Creating cluster 'kind-1' ...
 ✓ Ensuring node image (kindest/node:v1.12.2)  
 ✓ [kind-1-control-plane] Creating node container 📦 
 ✗ [kind-1-control-plane] Fixing mounts 🗻 
Error: failed to create cluster: exit status 1
Usage:  
  kind create cluster [flags]
        
Flags:  
      --config string   path to a kind config file
  -h, --help            help for cluster
      --image string    node docker image to use for booting the cluster
      --name string     cluster context name (default "1")
      --retain          retain nodes for debugging when cluster creation fails
      --wait duration   Wait for control plane node to be ready (default 0s)

Global Flags:
      --loglevel string   logrus log level [panic, fatal, error, warning, info, debug] (default "warning")

failed to create cluster: exit status 1
ed@ed-2a-bcc-llvm:~$ docker version
Client:
 Version:           18.09.0
 API version:       1.39
 Go version:        go1.10.4
 Git commit:        4d60db4
 Built:             Wed Nov  7 00:52:41 2018
 OS/Arch:           linux/arm64
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          18.09.0
  API version:      1.39 (minimum version 1.12)
  Go version:       go1.10.4
  Git commit:       4d60db4
  Built:            Wed Nov  7 00:17:01 2018
  OS/Arch:          linux/arm64
  Experimental:     false

[vielmetti]

Looking at https://github.com/kubernetes-sigs/kind/blob/master/pkg/cluster/context.go#L196-L206 where the code errors out, there's a TODO for logging from @BenTheElder .

[vielmetti]

Looks like the underlying reason is that kindest/node is not multiarchitecture.

ed@ed-2a-bcc-llvm:~$ docker run --rm mplatform/mquery kindest/node:v1.12.2
Image: kindest/node:v1.12.2
 * Manifest List: No
 * Supports: amd64/linux

[tao12345666333]

Yes, now we only hava amd64 architecture image. https://github.com/kubernetes-sigs/kind/blob/master/images/base/Dockerfile#L28-L33

[neolit123]

/priority important-longterm
/kind feature

[BenTheElder]

@dims hacked up a working version of this: https://paste.fedoraproject.org/paste/gdlF9fqXeSADK-aPN-sEbw/raw 🎉
I think we might want to put a little more thought into how to do this well like #188, but this should be doable. Tentatively tracking this for kind 1.0 in Q1 2019.