Fix BuildKit Dockerfile

Signed-off-by: Christopher Crone <christopher.crone@docker.com>

Dockerfile.buildkit

@@ -21,7 +21,7 @@ ARG VERSION
 ARG IMAGE_REPO_PREFIX
 ENV GITCOMMIT=$GITCOMMIT VERSION=$VERSION BUILDTIME=$BUILDTIME IMAGE_REPO_PREFIX=$IMAGE_REPO_PREFIX
 ENV CGO_ENABLED=0
-RUN --mount=target=/root/.cache,type=cache make bin/compose-controller bin/compose-controller.test e2e-binary bin/installer bin/api-server bin/api-server.test
+RUN --mount=target=/root/.cache,type=cache make bin/compose-controller bin/compose-controller.test e2e-binary bin/installer bin/api-server bin/api-server.test bin/e2e_benchmark
 RUN go get github.com/onsi/ginkgo/ginkgo
 RUN curl -LO https://storage.googleapis.com/kubernetes-release/release/v1.12.4/bin/linux/amd64/kubectl && \
   chmod +x ./kubectl && \
@@ -37,6 +37,12 @@ COPY --from=build /go/src/github.com/docker/compose-on-kubernetes/e2e/e2e.test /
 COPY --from=build /go/src/github.com/docker/compose-on-kubernetes/e2e/retrieve-coverage /retrieve-coverage
 COPY --from=build /bin/kubectl /bin/kubectl
 
+# e2e-benchmark
+FROM runbase AS compose-e2e-benchmark
+ENTRYPOINT ["/e2e_benchmark", "--kubeconfig=/kind-config", "--"]
+COPY --from=build /go/src/github.com/docker/compose-on-kubernetes/bin/e2e_benchmark /e2e_benchmark
+COPY --from=build /bin/kubectl /bin/kubectl
+
 # compose-installer (retrieved with --target=compose-installer)
 FROM runbase AS compose-installer
 ENTRYPOINT ["/installer"]