Enable to run build and invoke in background

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>

hack/dockerfiles/generated-files.Dockerfile

@@ -0,0 +1,60 @@
+# Forked from https://github.com/moby/buildkit/blob/e1b3b6c4abf7684f13e6391e5f7bc9210752687a/hack/dockerfiles/generated-files.Dockerfile
+# Copyright The BuildKit Authors.
+# Copyright The Buildx Authors.
+# Licensed under the Apache License, Version 2.0
+
+# syntax=docker/dockerfile-upstream:master
+
+ARG GO_VERSION="1.19"
+ARG PROTOC_VERSION="3.11.4"
+
+# protoc is dynamically linked to glibc so can't use alpine base
+FROM golang:${GO_VERSION}-buster AS base
+RUN apt-get update && apt-get --no-install-recommends install -y git unzip
+ARG PROTOC_VERSION
+ARG TARGETOS
+ARG TARGETARCH
+RUN <<EOT
+  set -e
+  arch=$(echo $TARGETARCH | sed -e s/amd64/x86_64/ -e s/arm64/aarch_64/)
+  wget -q https://github.com/protocolbuffers/protobuf/releases/download/v${PROTOC_VERSION}/protoc-${PROTOC_VERSION}-${TARGETOS}-${arch}.zip
+  unzip protoc-${PROTOC_VERSION}-${TARGETOS}-${arch}.zip -d /usr/local
+EOT
+WORKDIR /go/src/github.com/docker/buildx
+
+FROM base AS tools
+RUN --mount=type=bind,target=.,rw \
+    --mount=type=cache,target=/root/.cache \
+    --mount=type=cache,target=/go/pkg/mod \
+    go install \
+      github.com/gogo/protobuf/protoc-gen-gogo \
+      github.com/gogo/protobuf/protoc-gen-gogofaster \
+      github.com/gogo/protobuf/protoc-gen-gogoslick \
+      github.com/golang/protobuf/protoc-gen-go
+
+FROM tools AS generated
+RUN --mount=type=bind,target=.,rw <<EOT
+  set -ex
+  go generate -mod=vendor -v ./...
+  mkdir /out
+  git ls-files -m --others -- ':!vendor' '**/*.pb.go' | tar -cf - --files-from - | tar -C /out -xf -
+EOT
+
+FROM scratch AS update
+COPY --from=generated /out /
+
+FROM base AS validate
+RUN --mount=type=bind,target=.,rw \
+    --mount=type=bind,from=generated,source=/out,target=/generated-files <<EOT
+  set -e
+  git add -A
+  if [ "$(ls -A /generated-files)" ]; then
+    cp -rf /generated-files/* .
+  fi
+  diff=$(git status --porcelain -- ':!vendor' '**/*.pb.go')
+  if [ -n "$diff" ]; then
+    echo >&2 'ERROR: The result of "go generate" differs. Please update with "make generated-files"'
+    echo "$diff"
+    exit 1
+  fi
+EOT