Issue #438: Rework machine/bundle API

The main goal is to separate the "extract bundle file" logic from "load
cached bundle info" in the API. This allows us to have more accurate
logging during VM startup: at the moment we always print "Extracting
bundle" even when it's already extracted. In the subsequent commits,
this will allow us to load an already cached bundle when the VM already
exists.

This is related to #438

Author: cfergeau

pkg/crc/machine/bundle/extract.go

@@ -6,30 +6,22 @@ import (
 	"io"
 	"os"
 	"path/filepath"
-	"strings"
+
+	"github.com/code-ready/crc/pkg/crc/constants"
 )
 
-func Extract(sourcepath string, destpath string) (string, error) {
+func Extract(sourcepath string) (*CrcBundleInfo, error) {
 	file, err := os.Open(sourcepath)
 
 	if err != nil {
-		return "", err
+		return nil, err
 	}
-
-	extractedPath := strings.Split(filepath.Base(file.Name()), ".crcbundle")[0]
-	extractedPath = filepath.Join(destpath, extractedPath)
-
-	_, err = os.Stat(extractedPath)
-	if err == nil {
-		return extractedPath, nil
-	}
-
 	defer file.Close()
 
 	var fileReader io.Reader = file
 
 	if fileReader, err = xz.NewReader(file, 0); err != nil {
-		return "", err
+		return nil, err
 	}
 
 	tarBallReader := tar.NewReader(fileReader)
@@ -41,10 +33,10 @@ func Extract(sourcepath string, destpath string) (string, error) {
 			if err == io.EOF {
 				break
 			}
-			return "", err
+			return nil, err
 		}
 		// get the individual filename and extract to the specified directory
-		filename := filepath.Join(destpath, header.Name)
+		filename := filepath.Join(constants.MachineCacheDir, header.Name)
 
 		switch header.Typeflag {
 		case tar.TypeDir:
@@ -53,7 +45,7 @@ func Extract(sourcepath string, destpath string) (string, error) {
 			err = os.MkdirAll(filename, os.FileMode(header.Mode))
 
 			if err != nil {
-				return "", err
+				return nil, err
 			}
 
 		case tar.TypeReg, tar.TypeGNUSparse:
@@ -62,15 +54,15 @@ func Extract(sourcepath string, destpath string) (string, error) {
 			writer, err := os.Create(filename)
 
 			if err != nil {
-				return "", err
+				return nil, err
 			}
 
 			io.Copy(writer, tarBallReader)
 
 			err = os.Chmod(filename, os.FileMode(header.Mode))
 
 			if err != nil {
-				return "", err
+				return nil, err
 			}
 
 			writer.Close()
@@ -81,5 +73,5 @@ func Extract(sourcepath string, destpath string) (string, error) {
 
 	}
 
-	return extractedPath, nil
+	return GetCachedBundleInfo(filepath.Base(sourcepath))
 }

pkg/crc/machine/bundle/metadata.go

@@ -5,7 +5,9 @@ import (
 	"fmt"
 	"github.com/code-ready/crc/pkg/crc/constants"
 	"io/ioutil"
+	"os"
 	"path/filepath"
+	"strings"
 )
 
 // Metadata structure to unmarshal the crc-bundle-info.json file
@@ -43,23 +45,41 @@ type CrcBundleInfo struct {
 	cachedPath string
 }
 
-func GetCrcBundleInfo(bundlePath string) (*CrcBundleInfo, error) {
-	var bundleInfo CrcBundleInfo
-	extractedPath, err := Extract(bundlePath, constants.MachineCacheDir)
+func getCachedBundlePath(bundleName string) string {
+	path := strings.TrimSuffix(bundleName, ".crcbundle")
+	return filepath.Join(constants.MachineCacheDir, path)
+}
+
+func (bundle *CrcBundleInfo) isCached() bool {
+	_, err := os.Stat(bundle.cachedPath)
+	return err == nil
+}
+
+func (bundle *CrcBundleInfo) readBundleInfo() error {
+	bundleInfoPath := bundle.resolvePath("crc-bundle-info.json")
+	f, err := ioutil.ReadFile(bundleInfoPath)
 	if err != nil {
-		return nil, fmt.Errorf("Error during extraction : %+v", err)
+		return fmt.Errorf("Error reading %s file : %+v", bundleInfoPath, err)
 	}
-	BundleInfoPath := filepath.Join(extractedPath, "crc-bundle-info.json")
-	f, err := ioutil.ReadFile(BundleInfoPath)
+
+	err = json.Unmarshal(f, bundle)
 	if err != nil {
-		return nil, fmt.Errorf("Error reading %s file : %+v", BundleInfoPath, err)
+		return fmt.Errorf("Error Unmarshal the data: %+v", err)
 	}
 
-	err = json.Unmarshal(f, &bundleInfo)
+	return nil
+}
+
+func GetCachedBundleInfo(bundleName string) (*CrcBundleInfo, error) {
+	var bundleInfo CrcBundleInfo
+	bundleInfo.cachedPath = getCachedBundlePath(bundleName)
+	if !bundleInfo.isCached() {
+		return nil, fmt.Errorf("Could not find cached bundle info")
+	}
+	err := bundleInfo.readBundleInfo()
 	if err != nil {
-		return nil, fmt.Errorf("Error Unmarshal the data: %+v", err)
+		return nil, err
 	}
-	bundleInfo.cachedPath = extractedPath
 	return &bundleInfo, nil
 }
 

pkg/crc/machine/machine.go

@@ -50,6 +50,17 @@ func fillClusterConfig(bundleInfo *bundle.CrcBundleInfo, clusterConfig *ClusterC
 	return nil
 }
 
+func getCrcBundleInfo(bundlePath string) (*bundle.CrcBundleInfo, error) {
+	bundleName := filepath.Base(bundlePath)
+	logging.Infof("Loading bundle: %s ...", bundleName)
+	bundleInfo, err := bundle.GetCachedBundleInfo(bundleName)
+	if err == nil {
+		return bundleInfo, nil
+	}
+	logging.Infof("Extracting bundle: %s ...", bundleName)
+	return bundle.Extract(bundlePath)
+}
+
 func Start(startConfig StartConfig) (StartResult, error) {
 	defer unsetMachineLogging()
 
@@ -64,8 +75,7 @@ func Start(startConfig StartConfig) (StartResult, error) {
 	libMachineAPIClient := libmachine.NewClient(constants.MachineBaseDir, constants.MachineCertsDir)
 	defer libMachineAPIClient.Close()
 
-	logging.Infof("Extracting bundle: %s ...", filepath.Base(startConfig.BundlePath))
-	crcBundleMetadata, err := bundle.GetCrcBundleInfo(startConfig.BundlePath)
+	crcBundleMetadata, err := getCrcBundleInfo(startConfig.BundlePath)
 	if err != nil {
 		result.Error = err.Error()
 		return *result, errors.Newf("Error to get bundle Metadata %v", err)
@@ -87,7 +97,6 @@ func Start(startConfig StartConfig) (StartResult, error) {
 		// Retrieve metadata info
 		diskPath := crcBundleMetadata.GetDiskImagePath()
 		machineConfig.DiskPathURL = fmt.Sprintf("file://%s", filepath.ToSlash(diskPath))
-
 		machineConfig.SSHKeyPath = crcBundleMetadata.GetSSHKeyPath()
 		machineConfig.KernelCmdLine = crcBundleMetadata.Nodes[0].KernelCmdLine
 		machineConfig.Initramfs = crcBundleMetadata.GetInitramfsPath()