Move hacks to hack (match k8s pattern).

hack/crawl/cmd/backend/Dockerfile

@@ -0,0 +1,14 @@
+FROM golang:1.11 AS build
+
+ARG GO111MODULE=on
+
+WORKDIR /go/src/sigs.k8s.io/kustomize/internal/tools
+COPY . /go/src/sigs.k8s.io/kustomize/internal/tools
+
+RUN go mod download
+RUN CGO_ENABLED=0 go install sigs.k8s.io/kustomize/internal/tools/cmd/backend/
+
+FROM scratch
+COPY --from=build /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
+COPY --from=build /go/bin/backend /
+ENTRYPOINT ["/backend"]

hack/crawl/cmd/backend/main.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"context"
+	"log"
+	"os"
+	server "sigs.k8s.io/kustomize/hack/crawl/backend"
+	"strconv"
+)
+
+func main() {
+	portStr := os.Getenv("PORT")
+	port, err := strconv.Atoi(portStr)
+	if portStr == "" || err != nil {
+		log.Fatalf("$PORT(%s) must be set to an integer\n", portStr)
+	}
+
+	ctx := context.Background()
+
+	ks, err := server.NewKustomizeSearch(ctx)
+	if err != nil {
+		log.Fatalf("Error creating kustomize server: %v", ks)
+	}
+
+	err = ks.Serve(port)
+	if err != nil {
+		log.Fatalf("Error while running server: %v", err)
+	}
+}