feat(kanikoExecute): preparation for multi-arch builds (#3515)

* feat(kanikoExecute): preparation for multi-arch builds

* missing files

cmd/golangBuild_generated.go

@@ -339,7 +339,7 @@ func golangBuildMetadata() config.StepData {
 					{
 						Name:        "targetArchitectures",
 						ResourceRef: []config.ResourceReference{},
-						Scope:       []string{"STEPS", "STAGES", "PARAMETERS"},
+						Scope:       []string{"GENERAL", "STEPS", "STAGES", "PARAMETERS"},
 						Type:        "[]string",
 						Mandatory:   true,
 						Aliases:     []config.Alias{},

cmd/kanikoExecute.go

@@ -42,6 +42,12 @@ func kanikoExecute(config kanikoExecuteOptions, telemetryData *telemetry.CustomD
 }
 
 func runKanikoExecute(config *kanikoExecuteOptions, telemetryData *telemetry.CustomData, commonPipelineEnvironment *kanikoExecuteCommonPipelineEnvironment, execRunner command.ExecRunner, httpClient piperhttp.Sender, fileUtils piperutils.FileUtils) error {
+	binfmtSupported, _ := docker.IsBinfmtMiscSupportedByHost(fileUtils)
+
+	if !binfmtSupported && len(config.TargetArchitectures) > 0 {
+		log.Entry().Warning("Be aware that the host doesn't support binfmt_misc and thus multi archtecture docker builds might not be possible")
+	}
+
 	// backward compatibility for parameter ContainerBuildOptions
 	if len(config.ContainerBuildOptions) > 0 {
 		config.BuildOptions = strings.Split(config.ContainerBuildOptions, " ")

cmd/kanikoExecute_generated.go

@@ -31,6 +31,7 @@ type kanikoExecuteOptions struct {
 	CustomTLSCertificateLinks        []string `json:"customTlsCertificateLinks,omitempty"`
 	DockerConfigJSON                 string   `json:"dockerConfigJSON,omitempty"`
 	DockerfilePath                   string   `json:"dockerfilePath,omitempty"`
+	TargetArchitectures              []string `json:"targetArchitectures,omitempty"`
 }
 
 type kanikoExecuteCommonPipelineEnvironment struct {
@@ -190,6 +191,7 @@ func addKanikoExecuteFlags(cmd *cobra.Command, stepConfig *kanikoExecuteOptions)
 	cmd.Flags().StringSliceVar(&stepConfig.CustomTLSCertificateLinks, "customTlsCertificateLinks", []string{}, "List containing download links of custom TLS certificates. This is required to ensure trusted connections to registries with custom certificates.")
 	cmd.Flags().StringVar(&stepConfig.DockerConfigJSON, "dockerConfigJSON", os.Getenv("PIPER_dockerConfigJSON"), "Path to the file `.docker/config.json` - this is typically provided by your CI/CD system. You can find more details about the Docker credentials in the [Docker documentation](https://docs.docker.com/engine/reference/commandline/login/).")
 	cmd.Flags().StringVar(&stepConfig.DockerfilePath, "dockerfilePath", `Dockerfile`, "Defines the location of the Dockerfile relative to the Jenkins workspace.")
+	cmd.Flags().StringSliceVar(&stepConfig.TargetArchitectures, "targetArchitectures", []string{``}, "Defines the target architectures for which the build should run using OS and architecture separated by a comma. (EXPERIMENTAL)")
 
 }
 
@@ -355,6 +357,15 @@ func kanikoExecuteMetadata() config.StepData {
 						Aliases:     []config.Alias{{Name: "dockerfile"}},
 						Default:     `Dockerfile`,
 					},
+					{
+						Name:        "targetArchitectures",
+						ResourceRef: []config.ResourceReference{},
+						Scope:       []string{"GENERAL", "STEPS", "STAGES", "PARAMETERS"},
+						Type:        "[]string",
+						Mandatory:   false,
+						Aliases:     []config.Alias{},
+						Default:     []string{``},
+					},
 				},
 			},
 			Containers: []config.Container{

pkg/docker/multiarch.go

@@ -0,0 +1,10 @@
+package docker
+
+import (
+	"github.com/SAP/jenkins-library/pkg/piperutils"
+)
+
+// IsBinfmtMiscSupportedByHost checks if the hosts kernel does support binfmt_misc
+func IsBinfmtMiscSupportedByHost(utils piperutils.FileUtils) (bool, error) {
+	return utils.DirExists("/proc/sys/fs/binfmt_misc")
+}

pkg/docker/multiarch_test.go

@@ -0,0 +1,31 @@
+package docker
+
+import (
+	"testing"
+
+	"github.com/SAP/jenkins-library/pkg/mock"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIsBinfmtMiscSupportedByHost(t *testing.T) {
+	t.Run("returns true - binfmt_misc supported by host", func(t *testing.T) {
+		utils := mock.FilesMock{}
+		utils.AddDir("/proc/sys/fs/binfmt_misc")
+
+		b, err := IsBinfmtMiscSupportedByHost(&utils)
+
+		if assert.NoError(t, err) {
+			assert.True(t, b)
+		}
+	})
+
+	t.Run("returns false - binfmt_misc not supported by host", func(t *testing.T) {
+		utils := mock.FilesMock{}
+
+		b, err := IsBinfmtMiscSupportedByHost(&utils)
+
+		if assert.NoError(t, err) {
+			assert.False(t, b)
+		}
+	})
+}

resources/metadata/golangBuild.yaml

@@ -159,6 +159,7 @@ spec:
         description: Defines the target architectures for which the build should run using OS and architecture separated by a comma.
         default: linux,amd64
         scope:
+          - GENERAL
           - STEPS
           - STAGES
           - PARAMETERS

resources/metadata/kanikoExecute.yaml

@@ -158,6 +158,15 @@ spec:
           - STAGES
           - STEPS
         default: Dockerfile
+      - name: targetArchitectures
+        type: "[]string"
+        description: Defines the target architectures for which the build should run using OS and architecture separated by a comma. (EXPERIMENTAL)
+        default: []
+        scope:
+          - GENERAL
+          - STEPS
+          - STAGES
+          - PARAMETERS
   outputs:
     resources:
       - name: commonPipelineEnvironment