Fix merge conflict, change flag to snapshot-mode

executor/cmd/root.go

@@ -23,25 +23,29 @@ import (
 	"github.com/GoogleCloudPlatform/k8s-container-builder/pkg/image"
 	"github.com/GoogleCloudPlatform/k8s-container-builder/pkg/snapshot"
 	"github.com/GoogleCloudPlatform/k8s-container-builder/pkg/util"
+	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 	"io/ioutil"
 	"os"
+	"path/filepath"
 )
 
 var (
 	dockerfilePath string
 	destination    string
 	srcContext     string
-	mtime          string
+	snapshotMode   string
+	bucket         string
 	logLevel       string
 )
 
 func init() {
-	RootCmd.PersistentFlags().StringVarP(&dockerfilePath, "dockerfile", "f", "/workspace/Dockerfile", "Path to the dockerfile to be built.")
+	RootCmd.PersistentFlags().StringVarP(&dockerfilePath, "dockerfile", "f", "Dockerfile", "Path to the dockerfile to be built.")
 	RootCmd.PersistentFlags().StringVarP(&srcContext, "context", "c", "", "Path to the dockerfile build context.")
+	RootCmd.PersistentFlags().StringVarP(&bucket, "bucket", "b", "", "Name of the GCS bucket from which to access build context as tarball.")
 	RootCmd.PersistentFlags().StringVarP(&destination, "destination", "d", "", "Registry the final image should be pushed to (ex: gcr.io/test/example:latest)")
-	RootCmd.PersistentFlags().StringVarP(&mtime, "mtime", "", "full", "Set this flag to change the file attributes inspected during snapshotting")
+	RootCmd.PersistentFlags().StringVarP(&snapshotMode, "snapshotMode", "", "full", "Set this flag to change the file attributes inspected during snapshotting")
 	RootCmd.PersistentFlags().StringVarP(&logLevel, "verbosity", "v", constants.DefaultLogLevel, "Log level (debug, info, warn, error, fatal, panic")
 }
 
@@ -51,6 +55,10 @@ var RootCmd = &cobra.Command{
 		return util.SetLogLevel(logLevel)
 	},
 	Run: func(cmd *cobra.Command, args []string) {
+		if err := resolveSourceContext(); err != nil {
+			logrus.Error(err)
+			os.Exit(1)
+		}
 		if err := execute(); err != nil {
 			logrus.Error(err)
 			os.Exit(1)
@@ -58,6 +66,33 @@ var RootCmd = &cobra.Command{
 	},
 }
 
+// resolveSourceContext unpacks the source context if it is a tar in a GCS bucket
+// it resets srcContext to be the path to the unpacked build context within the image
+func resolveSourceContext() error {
+	if srcContext == "" && bucket == "" {
+		return errors.New("please specify a path to the build context with the --context flag or a GCS bucket with the --bucket flag")
+	}
+	if srcContext != "" && bucket != "" {
+		return errors.New("please specify either --bucket or --context as the desired build context")
+	}
+	if srcContext != "" {
+		return nil
+	}
+	logrus.Infof("Using GCS bucket %s as source context", bucket)
+	buildContextPath := constants.BuildContextDir
+	if err := util.UnpackTarFromGCSBucket(bucket, buildContextPath); err != nil {
+		return err
+	}
+	logrus.Debugf("Unpacked tar from %s to path %s", bucket, buildContextPath)
+	srcContext = buildContextPath
+	// If path to dockerfile doesn't exist, assume it is in the unpacked tar
+	if !util.FilepathExists(dockerfilePath) {
+		logrus.Debugf("Expecting dockerfile to be located at %s within the tar build context", dockerfilePath)
+		dockerfilePath = filepath.Join(srcContext, dockerfilePath)
+	}
+	return nil
+}
+
 func execute() error {
 	// Parse dockerfile and unpack base image to root
 	d, err := ioutil.ReadFile(dockerfilePath)
@@ -125,13 +160,31 @@ func execute() error {
 		}
 	}
 	// Push the image
+	if err := setDefaultEnv(); err != nil {
+		return err
+	}
 	return image.PushImage(sourceImage, destination)
 }
 
 func getHasher() func(string) (string, error) {
-	if mtime == "time" {
+	if snapshotMode == "time" {
 		logrus.Info("Only file modification time will be considered when snapshotting")
 		return util.MtimeHasher()
 	}
 	return util.Hasher()
 }
+
+// setDefaultEnv sets default values for HOME and PATH so that
+// config.json and docker-credential-gcr can be accessed
+func setDefaultEnv() error {
+	defaultEnvs := map[string]string{
+		"HOME": "/root",
+		"PATH": "/usr/local/bin/",
+	}
+	for key, val := range defaultEnvs {
+		if err := os.Setenv(key, val); err != nil {
+			return err
+		}
+	}
+	return nil
+}