Rewrite a few scripts in Go and remove unneeded services

cmd/control/preload.go

@@ -0,0 +1,106 @@
+package control
+
+import (
+	"compress/gzip"
+	"context"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path"
+	"regexp"
+	"strings"
+
+	"github.com/codegangsta/cli"
+
+	log "github.com/Sirupsen/logrus"
+	dockerClient "github.com/docker/engine-api/client"
+	"github.com/rancher/os/docker"
+)
+
+const (
+	userImagesPreloadDirectory = "/var/lib/rancher/preload/docker"
+)
+
+func preloadImagesAction(c *cli.Context) error {
+	return PreloadImages(docker.NewDefaultClient, userImagesPreloadDirectory)
+}
+
+func shouldLoad(file string) bool {
+	if strings.HasSuffix(file, ".done") {
+		return false
+	}
+	if _, err := os.Stat(fmt.Sprintf("%s.done", file)); err == nil {
+		return false
+	}
+	return true
+}
+
+func PreloadImages(clientFactory func() (dockerClient.APIClient, error), imagesDir string) error {
+	var client dockerClient.APIClient
+	clientInitialized := false
+
+	if _, err := os.Stat(imagesDir); os.IsNotExist(err) {
+		if err = os.MkdirAll(imagesDir, 0755); err != nil {
+			return err
+		}
+	} else if err != nil {
+		return err
+	}
+
+	files, err := ioutil.ReadDir(imagesDir)
+	if err != nil {
+		return err
+	}
+
+	for _, file := range files {
+		filename := path.Join(imagesDir, file.Name())
+		if !shouldLoad(filename) {
+			continue
+		}
+
+		image, err := os.Open(filename)
+		if err != nil {
+			return err
+		}
+		var imageReader io.Reader
+		imageReader = image
+		match, err := regexp.MatchString(".t?gz$", file.Name())
+		if err != nil {
+			return err
+		}
+		if match {
+			imageReader, err = gzip.NewReader(image)
+			if err != nil {
+				return err
+			}
+		}
+
+		if !clientInitialized {
+			client, err = clientFactory()
+			if err != nil {
+				return err
+			}
+			clientInitialized = true
+		}
+
+		log.Infof("Loading image %s", filename)
+		if _, err = client.ImageLoad(context.Background(), imageReader, false); err != nil {
+			return err
+		}
+
+		if err = image.Close(); err != nil {
+			return err
+		}
+
+		doneStamp, err := os.Create(fmt.Sprintf("%s.done", filename))
+		if err != nil {
+			return err
+		}
+		if err = doneStamp.Close(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}