Add separate makefile target for preloaded images

and convert shell script to go script

Makefile

@@ -502,13 +502,19 @@ storage-provisioner-image: out/storage-provisioner-$(GOARCH) ## Build storage-pr
 	docker build -t $(STORAGE_PROVISIONER_IMAGE) -f deploy/storage-provisioner/Dockerfile  --build-arg arch=$(GOARCH) .
 
 .PHONY: kic-base-image
-kic-base-image: generate-preloaded-images-tar ## builds the base image used for kic.
+kic-base-image: ## builds the base image used for kic.
+	docker rmi -f $(REGISTRY)/kicbase:v0.0.5-snapshot || true
+	docker build -f ./hack/images/kicbase.Dockerfile -t $(REGISTRY)/kicbase:v0.0.5-snapshot  --build-arg COMMIT_SHA=${VERSION}-$(COMMIT)  .
+
+
+.PHONY: kic-preloaded-base-image
+kic-preloaded-base-image: generate-preloaded-images-tar ## builds the base image used for kic.
 	docker rmi -f $(REGISTRY)/kicbase:v0.0.5-k8s-${KUBERNETES_VERSION} || true
 	docker build -f ./hack/images/kicbase.Dockerfile -t $(REGISTRY)/kicbase:v0.0.5-k8s-${KUBERNETES_VERSION}  --build-arg COMMIT_SHA=${VERSION}-$(COMMIT) --build-arg KUBERNETES_VERSION=${KUBERNETES_VERSION} .
 
 .PHONY: generate-preloaded-images-tar
 generate-preloaded-images-tar: out/minikube
-	KUBERNETES_VERSION=${KUBERNETES_VERSION} ./hack/preload-images/generate-preloaded-images-tar.sh
+	KUBERNETES_VERSION=${KUBERNETES_VERSION} go run ./hack/preload-images/preload_images.go
 
 
 .PHONY: push-storage-provisioner-image

hack/preload-images/generate-preloaded-images-tar.sh

@@ -1,32 +0,0 @@
-#!/bin/bash
-
-# Copyright 2016 The Kubernetes Authors All rights reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-set -ex 
-
-PROFILE=generate-preloaded-images-tar
-KUBERNETES_VERSION=${KUBERNETES_VERSION:-""}
-TARBALL_FILENAME=preloaded-images-k8s-$KUBERNETES_VERSION.tar
-
-function delete_minikube {
-    out/minikube delete --profile=$PROFILE
-}
-
-trap "delete_minikube" ERR
-
-out/minikube start --memory=10000 --profile=$PROFILE --kubernetes-version=$KUBERNETES_VERSION
-out/minikube ssh --profile=$PROFILE -- sudo tar cvf $TARBALL_FILENAME /var/lib/docker 
-scp -o StrictHostKeyChecking=no  -i $(out/minikube ssh-key --profile=$PROFILE) docker@$(out/minikube ip --profile=$PROFILE):/home/docker/$TARBALL_FILENAME out/$TARBALL_FILENAME
-delete_minikube

hack/preload-images/preload_images.go

@@ -0,0 +1,116 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+
+	"github.com/pkg/errors"
+)
+
+const (
+	profile      = "generate-preloaded-images-tar"
+	minikubePath = "out/minikube"
+)
+
+var (
+	kubernetesVersion = ""
+	tarballFilename   = ""
+)
+
+func init() {
+	if kv := os.Getenv("KUBERNETES_VERSION"); kv != "" {
+		kubernetesVersion = kv
+	} else {
+		fmt.Println("Please pass in kubernetes version via the KUBERNETES_VERSION environment variable")
+		os.Exit(1)
+	}
+	tarballFilename = fmt.Sprintf("preloaded-images-k8s-%s.tar", kubernetesVersion)
+}
+
+func main() {
+	if err := executePreloadImages(); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+}
+
+func executePreloadImages() error {
+	defer deleteMinikube()
+	if err := startMinikube(); err != nil {
+		return err
+	}
+	if err := createImageTarball(); err != nil {
+		return err
+	}
+	return copyTarballToHost()
+}
+
+func startMinikube() error {
+	cmd := exec.Command(minikubePath, "start", "-p", profile, "--memory", "10000", "--kubernetes-version", kubernetesVersion)
+	cmd.Stdout = os.Stdout
+	return cmd.Run()
+}
+
+func createImageTarball() error {
+	cmd := exec.Command(minikubePath, "ssh", "-p", profile, "--", "sudo", "tar", "cvf", tarballFilename, "/var/lib/docker")
+	cmd.Stdout = os.Stdout
+	return cmd.Run()
+}
+
+func copyTarballToHost() error {
+	sshKey, err := runCmdCaptureStdout([]string{minikubePath, "ssh-key", "-p", profile})
+	if err != nil {
+		return errors.Wrap(err, "getting ssh-key")
+	}
+
+	ip, err := runCmdCaptureStdout([]string{minikubePath, "ip", "-p", profile})
+	if err != nil {
+		return errors.Wrap(err, "getting ip")
+	}
+
+	dest := filepath.Join("out/", tarballFilename)
+	args := fmt.Sprintf("scp -o StrictHostKeyChecking=no -i %s docker@%s:/home/docker/%s %s", sshKey, ip, tarballFilename, dest)
+	_, err = runCmdCaptureStdout(strings.Split(args, " "))
+	return err
+}
+
+func deleteMinikube() error {
+	cmd := exec.Command(minikubePath, "delete", "-p", profile)
+	cmd.Stdout = os.Stdout
+	return cmd.Run()
+}
+
+func runCmdCaptureStdout(command []string) (string, error) {
+	cmd := exec.Command(command[0], command[1:]...)
+	buf := bytes.NewBuffer([]byte{})
+	cmd.Stdout = buf
+	if err := cmd.Run(); err != nil {
+		return "", err
+	}
+	stdout, err := ioutil.ReadAll(buf)
+	if err != nil {
+		return "", err
+	}
+	return strings.Trim(string(stdout), "\n "), nil
+}