Running
docker run -it -v $PWD:/tmp k8s.gcr.io/kube-proxy:v1.15.1 cp /usr/local/bin/kube-proxy /tmp
file kube-proxy
gives a different result depending on which architecture I am on e.g. on CoreOS
Container Linux by CoreOS stable (2135.5.0)
core@node1 ~ $ file kube-proxy
kube-proxy: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), statically linked, stripped
and on HypriotOS
HypriotOS/armv7: [email protected] in ~
$ file kube-proxy
kube-proxy: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), statically linked, stripped
How is this working?
Container runtimes are architecture aware & container registries support defining images for multiple architectures. Docker automatically pulls the correct image for the platform it's running on.
https://blog.docker.com/2017/09/docker-official-images-now-multi-platform/