Morlay

close https://github.com/docker/buildx/issues/399 and discussing here. @FernandoMiguel any suggestion in this case?. i need cache /go/pkg/mod for multi workflows in build stage. but the `--cache-to` couldn't expose the cached files (`/var/lib/buildkit`)...

here example **workflow.yml** https://github.com/querycap/istio/blob/master/.github/workflows/istio-pilot.yml **Dockerfile** https://github.com/querycap/istio/blob/master/build/istio/Dockerfile.pilot and the logs https://pipelines.actions.githubusercontent.com/qcc22rpVKD7YzUzpABpz6Nbu6TDqQ0MFAEbSsnK9GDsCU4Hq5g/_apis/pipelines/1/runs/325/signedlogcontent/3?urlExpires=2020-09-24T13%3A32%3A15.1287086Z&urlSigningMethod=HMACV1&urlSignature=MDAD0FQhxCis3TFZLKqjsdmvB2m0iiCBWv6G9FyDOGs%3D `--cache-from` `--cache-to` host path `/tmp/.buildx/cache`  `--mount=type=cache` not working  i understands how `--mount=type=cache` work. i have no idea to...

@FernandoMiguel mount host path like `/tmp/buildkit` to buildkit to `/var/lib/buildkit`, then i add `/tmp/buildkit` to actions cache. could this be possible?

```shell docker buildx create --use --name localbuild docker buildx inspect localbuild --bootstrap # recreate buildkit with host path docker rm -f buildx_buildkit_localbuild0 docker run --privileged -d --name=buildx_buildkit_localbuild0 -v=/tmp/buildkit:/var/lib/buildkit moby/buildkit:buildx-stable-1 ```...

github actions use a non-root user, but `/var/lib/buildkit/runc-overlayfs` only for root user. and `/var/lib/buildkit/runc-overlayfs` always in changing. i give up to use this way. need find other hacks.

@howardjohn Yes, it could be, but project like tools, proxy may need to changes a lot to bump the new workflow.

@howardjohn could you help @AWSjswinney to setup an env for arm64 builds. I understand your points. so let's do like that.

Yes. We could just setup a cluster for arm64 only. Once this PR merge https://github.com/istio/istio/pull/33763. (hope it could be before release-1.11) we could easy to build arm64 only or multi-arch...

Blocked by https://github.com/kubernetes/test-infra/pull/24783

The 'red' step is we need todo. ```mermaid graph LR classDef todo fill:#ffb3b3,stroke:#000; classDef repo fill:#ffb808,stroke:#000; object-storage[(object storage)] subgraph prow-arm64 image-build-tools-proxy-arm64(build-tools-proxy:arm64):::todo -.->build-envoy-arm64((build envoy arm64)):::todo end subgraph prow-amd64 image-build-tools-proxy-amd64(build-tools-proxy:amd64) -.->build-envoy-amd64((build envoy...