cnbBuild: use DockerCredentials secret during custom buildpacks download (#3138)

cmd/cnbBuild.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"os"
 	"path"
+	"path/filepath"
 	"regexp"
 	"strings"
 
@@ -31,10 +32,10 @@ type cnbBuildUtilsBundle struct {
 	*docker.Client
 }
 
-func setCustomBuildpacks(bpacks []string, utils cnbutils.BuildUtils) (string, string, error) {
+func setCustomBuildpacks(bpacks []string, dockerCreds string, utils cnbutils.BuildUtils) (string, string, error) {
 	buildpacksPath := "/tmp/buildpacks"
 	orderPath := "/tmp/buildpacks/order.toml"
-	newOrder, err := cnbutils.DownloadBuildpacks(buildpacksPath, bpacks, utils)
+	newOrder, err := cnbutils.DownloadBuildpacks(buildpacksPath, bpacks, dockerCreds, utils)
 	if err != nil {
 		return "", "", err
 	}
@@ -153,6 +154,22 @@ func copyFile(source, target string, utils cnbutils.BuildUtils) error {
 	return nil
 }
 
+func prepareDockerConfig(source string, utils cnbutils.BuildUtils) (string, error) {
+	if filepath.Base(source) != "config.json" {
+		log.Entry().Debugf("Renaming docker config file from '%s' to 'config.json'", filepath.Base(source))
+
+		newPath := filepath.Join(filepath.Dir(source), "config.json")
+		err := utils.FileRename(source, newPath)
+		if err != nil {
+			return "", err
+		}
+
+		return newPath, nil
+	}
+
+	return source, nil
+}
+
 func runCnbBuild(config *cnbBuildOptions, telemetryData *telemetry.CustomData, utils cnbutils.BuildUtils, commonPipelineEnvironment *cnbBuildCommonPipelineEnvironment) error {
 	var err error
 
@@ -178,10 +195,16 @@ func runCnbBuild(config *cnbBuildOptions, telemetryData *telemetry.CustomData, u
 		}
 	}
 
+	dockerConfigFile := ""
 	dockerConfig := &configfile.ConfigFile{}
 	dockerConfigJSON := []byte(`{"auths":{}}`)
 	if len(config.DockerConfigJSON) > 0 {
-		dockerConfigJSON, err = utils.FileRead(config.DockerConfigJSON)
+		dockerConfigFile, err = prepareDockerConfig(config.DockerConfigJSON, utils)
+		if err != nil {
+			log.SetErrorCategory(log.ErrorConfiguration)
+			return errors.Wrapf(err, "failed to rename DockerConfigJSON file '%v'", config.DockerConfigJSON)
+		}
+		dockerConfigJSON, err = utils.FileRead(dockerConfigFile)
 		if err != nil {
 			log.SetErrorCategory(log.ErrorConfiguration)
 			return errors.Wrapf(err, "failed to read DockerConfigJSON file '%v'", config.DockerConfigJSON)
@@ -241,7 +264,7 @@ func runCnbBuild(config *cnbBuildOptions, telemetryData *telemetry.CustomData, u
 
 	if config.Buildpacks != nil && len(config.Buildpacks) > 0 {
 		log.Entry().Infof("Setting custom buildpacks: '%v'", config.Buildpacks)
-		buildpacksPath, orderPath, err = setCustomBuildpacks(config.Buildpacks, utils)
+		buildpacksPath, orderPath, err = setCustomBuildpacks(config.Buildpacks, dockerConfigFile, utils)
 		defer utils.RemoveAll(buildpacksPath)
 		defer utils.RemoveAll(orderPath)
 		if err != nil {

cmd/cnbBuild_test.go

@@ -84,14 +84,14 @@ func TestRunCnbBuild(t *testing.T) {
 		assert.Equal(t, []string{fmt.Sprintf("%s/%s:%s", registry, config.ContainerImageName, config.ContainerImageTag), fmt.Sprintf("%s/%s:latest", registry, config.ContainerImageName)}, runner.Calls[2].Params)
 	})
 
-	t.Run("success case (custom buildpacks and custom env variables)", func(t *testing.T) {
+	t.Run("success case (custom buildpacks and custom env variables, renaming docker conf file)", func(t *testing.T) {
 		t.Parallel()
 		registry := "some-registry"
 		config := cnbBuildOptions{
 			ContainerImageName:   "my-image",
 			ContainerImageTag:    "0.0.1",
 			ContainerRegistryURL: registry,
-			DockerConfigJSON:     "/path/to/config.json",
+			DockerConfigJSON:     "/path/to/test.json",
 			Buildpacks:           []string{"test"},
 			BuildEnvVars:         []string{"FOO=BAR"},
 		}
@@ -128,7 +128,21 @@ func TestRunCnbBuild(t *testing.T) {
 		assert.EqualError(t, err, "failed to parse DockerConfigJSON file '/path/to/config.json': json: cannot unmarshal string into Go struct field ConfigFile.auths of type types.AuthConfig")
 	})
 
-	t.Run("error case: DockerConfigJSON file not there", func(t *testing.T) {
+	t.Run("error case: DockerConfigJSON file not there (config.json)", func(t *testing.T) {
+		t.Parallel()
+		config := cnbBuildOptions{
+			ContainerImageName: "my-image",
+			DockerConfigJSON:   "not-there/config.json",
+		}
+
+		utils := newCnbBuildTestsUtils()
+		addBuilderFiles(&utils)
+
+		err := runCnbBuild(&config, nil, &utils, &commonPipelineEnvironment)
+		assert.EqualError(t, err, "failed to read DockerConfigJSON file 'not-there/config.json': could not read 'not-there/config.json'")
+	})
+
+	t.Run("error case: DockerConfigJSON file not there (not config.json)", func(t *testing.T) {
 		t.Parallel()
 		config := cnbBuildOptions{
 			ContainerImageName: "my-image",
@@ -139,7 +153,7 @@ func TestRunCnbBuild(t *testing.T) {
 		addBuilderFiles(&utils)
 
 		err := runCnbBuild(&config, nil, &utils, &commonPipelineEnvironment)
-		assert.EqualError(t, err, "failed to read DockerConfigJSON file 'not-there': could not read 'not-there'")
+		assert.EqualError(t, err, "failed to rename DockerConfigJSON file 'not-there': renaming file 'not-there' is not supported, since it does not exist, or is not a leaf-entry")
 	})
 
 	t.Run("error case: dockerImage is not a valid builder", func(t *testing.T) {

pkg/cnbutils/buildpack.go

@@ -4,6 +4,7 @@ package cnbutils
 import (
 	"encoding/json"
 	"fmt"
+	"os"
 	"path/filepath"
 	"strings"
 
@@ -25,7 +26,12 @@ type License struct {
 	URI  string `json:"uri"`
 }
 
-func DownloadBuildpacks(path string, bpacks []string, utils BuildUtils) (Order, error) {
+func DownloadBuildpacks(path string, bpacks []string, dockerCreds string, utils BuildUtils) (Order, error) {
+
+	if dockerCreds != "" {
+		os.Setenv("DOCKER_CONFIG", filepath.Dir(dockerCreds))
+	}
+
 	var order Order
 	for _, bpack := range bpacks {
 		var bpackMeta BuildPackMetadata

pkg/cnbutils/buildpack_test.go

@@ -16,7 +16,7 @@ var mockUtils = MockUtils{
 func TestBuildpackDownload(t *testing.T) {
 	t.Run("successfully downloads a buildpack", func(t *testing.T) {
 		mockUtils.AddDir("/tmp/testtest")
-		_, err := DownloadBuildpacks("/test", []string{"test"}, mockUtils)
+		_, err := DownloadBuildpacks("/test", []string{"test"}, "/test/config.json", mockUtils)
 
 		assert.NoError(t, err)
 		assert.True(t, mockUtils.HasRemovedFile("/tmp/testtest"))