Support for relocation mapping files (#778)

* duffle relocate creates relocation mapping file

Ref #772

* Accept relocation mapping file on install, upgrade, and run

Fixes #772

* Address review comments

cmd/duffle/install.go

@@ -28,6 +28,9 @@ Example:
 
 Note: To install a bundle, use $ duffle bundle install or $ duffle install. They are aliases for the same action.
 
+If the bundle has been relocated, you can pass the relocation mapping
+file created by duffle relocate using the --relocation-mapping flag.
+
 Different drivers are available for executing the duffle invocation
 image. The following drivers are built-in:
 
@@ -56,13 +59,14 @@ type installCmd struct {
 	home   home.Home
 	out    io.Writer
 
-	driver           string
-	credentialsFiles []string
-	valuesFile       string
-	setParams        []string
-	setFiles         []string
-	bundleIsFile     bool
-	name             string
+	driver            string
+	credentialsFiles  []string
+	valuesFile        string
+	setParams         []string
+	setFiles          []string
+	bundleIsFile      bool
+	name              string
+	relocationMapping string
 }
 
 func newInstallCmd(w io.Writer) *cobra.Command {
@@ -83,6 +87,7 @@ func newInstallCmd(w io.Writer) *cobra.Command {
 
 	f := cmd.Flags()
 	f.BoolVarP(&install.bundleIsFile, "bundle-is-file", "f", false, "Indicates that the bundle source is a file path")
+	f.StringVarP(&install.relocationMapping, "relocation-mapping", "m", "", "Path of relocation mapping JSON file")
 	f.StringVarP(&install.driver, "driver", "d", "docker", "Specify a driver name")
 	f.StringVarP(&install.valuesFile, "parameters", "p", "", "Specify file containing parameters. Formats: toml, MORE SOON")
 	f.StringArrayVarP(&install.credentialsFiles, "credentials", "c", []string{}, "Specify credentials to use inside the bundle. This can be a credentialset name or a path to a file.")
@@ -112,7 +117,7 @@ func (i *installCmd) run() error {
 		return err
 	}
 
-	driverImpl, err := prepareDriver(i.driver)
+	driverImpl, err := prepareDriver(i.driver, i.relocationMapping)
 	if err != nil {
 		return err
 	}

cmd/duffle/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"io/ioutil"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -96,10 +97,10 @@ func must(err error) {
 }
 
 // prepareDriver prepares a driver per the user's request.
-func prepareDriver(driverName string) (driver.Driver, error) {
+func prepareDriver(driverName string, relMap string) (driver.Driver, error) {
 	driverImpl, err := duffleDriver.Lookup(driverName)
 	if err != nil {
-		return driverImpl, err
+		return nil, err
 	}
 
 	// Load any driver-specific config out of the environment.
@@ -111,7 +112,45 @@ func prepareDriver(driverName string) (driver.Driver, error) {
 		configurable.SetConfig(driverCfg)
 	}
 
-	return driverImpl, err
+	rm, err := loadRelMapping(relMap)
+	if err != nil {
+		return nil, err
+	}
+
+	// wrap the driver so any relocation mapping is mounted
+	return &driverWithRelocationMapping{
+		driver:     driverImpl,
+		relMapping: rm,
+	}, nil
+}
+
+type driverWithRelocationMapping struct {
+	driver     driver.Driver
+	relMapping string
+}
+
+func (d *driverWithRelocationMapping) Run(op *driver.Operation) error {
+	// if there is a relocation mapping, ensure it is mounted
+	if d.relMapping != "" {
+		op.Files["/cnab/app/relocation-mapping.json"] = d.relMapping
+	}
+	return d.driver.Run(op)
+}
+
+func (d *driverWithRelocationMapping) Handles(it string) bool {
+	return d.driver.Handles(it)
+}
+
+func loadRelMapping(relMap string) (string, error) {
+	if relMap != "" {
+		data, err := ioutil.ReadFile(relMap)
+		if err != nil {
+			return "", fmt.Errorf("failed to read relocation mapping from %s: %v", relMap, err)
+		}
+		return string(data), nil
+	}
+
+	return "", nil
 }
 
 func loadBundle(bundleFile string) (*bundle.Bundle, error) {

cmd/duffle/relocate.go

@@ -1,10 +1,10 @@
 package main
 
 import (
+	"encoding/json"
 	"fmt"
 	"io"
 	"io/ioutil"
-	"path/filepath"
 	"strconv"
 	"strings"
 
@@ -23,26 +23,28 @@ import (
 const (
 	relocateDesc = `
 Relocates any docker and oci images, including invocation images, referenced by a bundle, tags and pushes the images to
-a registry, and creates a new bundle with an updated invocation images section and an updated image map.
+a registry, and creates a relocation mapping JSON file.
 
 The --repository-prefix flag determines the repositories for the relocated images.
 Each image is tagged with a name starting with the given prefix and pushed to the repository.
 
 For example, if the repository-prefix is example.com/user, the image istio/proxyv2 is relocated
 to a name starting with example.com/user/ and pushed to a repository hosted by example.com.
+
+The generated relocation mapping file maps the original image references to their relocated counterparts. This file is
+an optional input to the install, upgrade, and run commands.
 `
 	invalidRepositoryChars = ":@\" "
 )
 
 type relocateCmd struct {
 	// args
-	inputBundle  string
-	outputBundle string
+	inputBundle string
 
 	// flags
-	repoPrefix         string
-	inputBundleIsFile  bool
-	outputBundleIsFile bool
+	repoPrefix        string
+	bundleIsFile      bool
+	relocationMapping string
 
 	// context
 	home home.Home
@@ -60,10 +62,9 @@ func newRelocateCmd(w io.Writer) *cobra.Command {
 		Use:   "relocate [INPUT-BUNDLE] [OUTPUT-BUNDLE]",
 		Short: "relocate images in a CNAB bundle",
 		Long:  relocateDesc,
-		Example: `duffle relocate helloworld hellorelocated --repository-prefix example.com/user
-duffle relocate path/to/bundle.json relocatedbundle --repository-prefix example.com/user --input-bundle-is-file
-duffle relocate helloworld path/to/relocatedbundle.json --repository-prefix example.com/user --output-bundle-is-file`,
-		Args: cobra.ExactArgs(2),
+		Example: `duffle relocate helloworld --relocation-mapping path/to/relmap.json --repository-prefix example.com/user
+duffle relocate path/to/bundle.json --relocation-mapping path/to/relmap.json --repository-prefix example.com/user --input-bundle-is-file`,
+		Args: cobra.ExactArgs(1),
 		PreRunE: func(cmd *cobra.Command, args []string) error {
 			// validate --repository-prefix if it is set, otherwise fall through so that cobra will report the missing flag in its usual manner
 			if cmd.Flags().Changed("repository-prefix") {
@@ -76,7 +77,6 @@ duffle relocate helloworld path/to/relocatedbundle.json --repository-prefix exam
 		},
 		RunE: func(cmd *cobra.Command, args []string) error {
 			relocate.inputBundle = args[0]
-			relocate.outputBundle = args[1]
 
 			relocate.home = home.Home(homePath())
 
@@ -88,9 +88,10 @@ duffle relocate helloworld path/to/relocatedbundle.json --repository-prefix exam
 	}
 
 	f := cmd.Flags()
-	f.BoolVarP(&relocate.inputBundleIsFile, "input-bundle-is-file", "", false, "Indicates that the input bundle source is a file path")
-	f.BoolVarP(&relocate.outputBundleIsFile, "output-bundle-is-file", "", false, "Indicates that the output bundle destination is a file path")
-	f.StringVarP(&relocate.repoPrefix, "repository-prefix", "r", "", "Prefix for relocated image names")
+	f.BoolVarP(&relocate.bundleIsFile, "bundle-is-file", "f", false, "Indicates that the input bundle source is a file path")
+	f.StringVarP(&relocate.relocationMapping, "relocation-mapping", "m", "", "Path for output relocation mapping JSON file")
+	cmd.MarkFlagRequired("relocation-mapping")
+	f.StringVarP(&relocate.repoPrefix, "repository-prefix", "p", "", "Prefix for relocated image names")
 	cmd.MarkFlagRequired("repository-prefix")
 
 	return cmd
@@ -102,22 +103,14 @@ func (r *relocateCmd) run() error {
 		return err
 	}
 
-	if err := r.relocate(bun); err != nil {
-		return err
-	}
-
-	return r.writeBundle(bun)
+	return r.relocate(bun)
 }
 
 func (r *relocateCmd) relocate(bun *bundle.Bundle) error {
-	// mutate the input bundle to become the output bundle
-	if !r.outputBundleIsFile {
-		bun.Name = r.outputBundle
-	}
-
+	relMap := make(map[string]string)
 	for i := range bun.InvocationImages {
 		ii := bun.InvocationImages[i]
-		modified, err := r.relocateImage(&ii.BaseImage)
+		modified, err := r.relocateImage(&ii.BaseImage, relMap)
 		if err != nil {
 			return err
 		}
@@ -128,7 +121,7 @@ func (r *relocateCmd) relocate(bun *bundle.Bundle) error {
 
 	for k := range bun.Images {
 		im := bun.Images[k]
-		modified, err := r.relocateImage(&im.BaseImage)
+		modified, err := r.relocateImage(&im.BaseImage, relMap)
 		if err != nil {
 			return err
 		}
@@ -137,10 +130,10 @@ func (r *relocateCmd) relocate(bun *bundle.Bundle) error {
 		}
 	}
 
-	return nil
+	return r.writeRelocationMapping(relMap)
 }
 
-func (r *relocateCmd) relocateImage(i *bundle.BaseImage) (bool, error) {
+func (r *relocateCmd) relocateImage(i *bundle.BaseImage, relMap map[string]string) (bool, error) {
 	if !isOCI(i.ImageType) && !isDocker(i.ImageType) {
 		return false, nil
 	}
@@ -161,9 +154,9 @@ func (r *relocateCmd) relocateImage(i *bundle.BaseImage) (bool, error) {
 		return false, fmt.Errorf("digest of image %s not preserved: old digest %s; new digest %s", i.Image, i.Digest, dig.String())
 	}
 
-	// update the imagemap
-	i.OriginalImage = i.Image
-	i.Image = rn.String()
+	// update the relocation map
+	relMap[i.Image] = rn.String()
+
 	return true, nil
 }
 
@@ -176,7 +169,7 @@ func isDocker(imageType string) bool {
 }
 
 func (r *relocateCmd) setup() (*bundle.Bundle, error) {
-	bundleFile, err := resolveBundleFilePath(r.inputBundle, r.home.String(), r.inputBundleIsFile)
+	bundleFile, err := resolveBundleFilePath(r.inputBundle, r.home.String(), r.bundleIsFile)
 	if err != nil {
 		return nil, err
 	}
@@ -193,30 +186,13 @@ func (r *relocateCmd) setup() (*bundle.Bundle, error) {
 	return bun, nil
 }
 
-func (r *relocateCmd) writeBundle(bf *bundle.Bundle) error {
-	data, digest, err := marshalBundle(bf)
+func (r *relocateCmd) writeRelocationMapping(relMap map[string]string) error {
+	rm, err := json.Marshal(relMap)
 	if err != nil {
-		return fmt.Errorf("cannot marshal bundle: %v", err)
-	}
-
-	if r.outputBundleIsFile {
-		if err := ioutil.WriteFile(r.outputBundle, data, 0644); err != nil {
-			return fmt.Errorf("cannot write bundle to %s: %v", r.outputBundle, err)
-		}
-		return nil
-	}
-
-	if err := ioutil.WriteFile(filepath.Join(r.home.Bundles(), digest), data, 0644); err != nil {
-		return fmt.Errorf("cannot store bundle : %v", err)
-
-	}
-
-	// record the new bundle in repositories.json
-	if err := recordBundleReference(r.home, bf.Name, bf.Version, digest); err != nil {
-		return fmt.Errorf("cannot record bundle: %v", err)
+		return err
 	}
 
-	return nil
+	return ioutil.WriteFile(r.relocationMapping, rm, 0644)
 }
 
 func validateRepository(repo string) error {