Install slirp4netns in dind rootless image

[tgreeve]

When doing docker build in docker:dind-rootless, there is a strange problem which resolving github.com returns NXDOMAIN.

alpinelinux/docker-alpine#155

I encounter this problem in both K8S (EKS 1.23) container and MacOS Docker-Desktop (4.17.0). The problem can be resolved by replacing vpnkit with slirp4netns as the network bridge. However, slirp4netns binary isn't installed in the latest version of docker:dind-rootless image.

Is it possible to do a apk add slirp4netns in dind-rootless build?

[tianon]

Duplicate of #274

[tgreeve]

Thanks, seemingly the CVEs and license issues prevent slirp4netns from being included in dind-rootless image.