feat: allow TanzuNet slug to be set in the Kilnfile stemcell criteria

internal/commands/find_stemcell_version.go

@@ -16,7 +16,6 @@ import (
 )
 
 const (
-	ErrStemcellOSInfoMustBeValid       = "stemcell os information is missing or invalid"
 	ErrStemcellMajorVersionMustBeValid = "stemcell major Version is missing or invalid"
 	TanzuNetRemotePath                 = "network.pivotal.io"
 )
@@ -52,19 +51,9 @@ func (cmd FindStemcellVersion) Execute(args []string) error {
 		return err
 	}
 
-	productSlug := ""
-
-	// Get Stemcell OS and major from Kilnfile
-	if kilnfile.Stemcell.OS == "ubuntu-xenial" {
-		productSlug = "stemcells-ubuntu-xenial"
-	} else if kilnfile.Stemcell.OS == "ubuntu-jammy" {
-		productSlug = "stemcells-ubuntu-jammy"
-	} else if kilnfile.Stemcell.OS == "windows2019" {
-		productSlug = "stemcells-windows-server"
-	}
-
-	if productSlug == "" {
-		return fmt.Errorf(ErrStemcellOSInfoMustBeValid)
+	productSlug, err := kilnfile.Stemcell.ProductSlug()
+	if err != nil {
+		return err
 	}
 
 	if kilnfile.Stemcell.Version == "" {

internal/commands/find_stemcell_version_test.go

@@ -112,7 +112,7 @@ release_sources:
 			})
 			It("returns the stemcell os info missing error message", func() {
 				Expect(executeErr).To(HaveOccurred())
-				Expect(executeErr).To(MatchError(ContainSubstring(commands.ErrStemcellOSInfoMustBeValid)))
+				Expect(executeErr).To(MatchError(ContainSubstring("stemcell slug not set")))
 			})
 		})
 

pkg/cargo/kilnfile.go

@@ -194,7 +194,25 @@ func (lock BOSHReleaseTarballLock) ParseVersion() (*semver.Version, error) {
 }
 
 type Stemcell struct {
-	Alias   string `yaml:"alias,omitempty"`
-	OS      string `yaml:"os"`
-	Version string `yaml:"version"`
+	Alias        string `yaml:"alias,omitempty"`
+	OS           string `yaml:"os"`
+	Version      string `yaml:"version"`
+	TanzuNetSlug string `yaml:"slug,omitempty"`
+}
+
+func (stemcell Stemcell) ProductSlug() (string, error) {
+	if stemcell.TanzuNetSlug != "" {
+		return stemcell.TanzuNetSlug, nil
+	}
+	// fall back behavior for compatability
+	switch stemcell.OS {
+	case "ubuntu-xenial":
+		return "stemcells-ubuntu-xenial", nil
+	case "ubuntu-jammy":
+		return "stemcells-ubuntu-jammy", nil
+	case "windows2019":
+		return "stemcells-windows-server", nil
+	default:
+		return "", fmt.Errorf("stemcell slug not set for os %s", stemcell.OS)
+	}
 }

pkg/cargo/kilnfile_test.go

@@ -5,8 +5,8 @@ import (
 
 	. "github.com/onsi/gomega"
 	"github.com/stretchr/testify/assert"
-
-	"gopkg.in/yaml.v2"
+	"github.com/stretchr/testify/require"
+	"gopkg.in/yaml.v3"
 )
 
 func TestComponentLock_yaml_marshal_order(t *testing.T) {
@@ -72,3 +72,52 @@ func TestKilnfileLock_UpdateBOSHReleaseTarballLockWithName(t *testing.T) {
 		})
 	}
 }
+
+func TestStemcell_ProductSlug(t *testing.T) {
+	for _, tt := range []struct {
+		Name                     string
+		Stemcell                 Stemcell
+		ExpSlug, ExpErrSubstring string
+	}{
+		{
+			Name:     "when using known os ubuntu-xenial",
+			Stemcell: Stemcell{OS: "ubuntu-xenial"},
+			ExpSlug:  "stemcells-ubuntu-xenial",
+		},
+		{
+			Name:     "when using known os ubuntu-jammy",
+			Stemcell: Stemcell{OS: "ubuntu-jammy"},
+			ExpSlug:  "stemcells-ubuntu-jammy",
+		},
+		{
+			Name:     "when using known os windows2019",
+			Stemcell: Stemcell{OS: "windows2019"},
+			ExpSlug:  "stemcells-windows-server",
+		},
+		{
+			Name:            "when slug is not set",
+			Stemcell:        Stemcell{OS: "orange"},
+			ExpErrSubstring: "stemcell slug not set",
+		},
+		{
+			Name:     "when slug is set",
+			Stemcell: Stemcell{TanzuNetSlug: "naval-orange"},
+			ExpSlug:  "naval-orange",
+		},
+		{
+			Name:     "when slug is set and os is a known value windows2019",
+			Stemcell: Stemcell{OS: "windows2019", TanzuNetSlug: "naval-orange"},
+			ExpSlug:  "naval-orange",
+		},
+	} {
+		t.Run(tt.Name, func(t *testing.T) {
+			productSlug, err := tt.Stemcell.ProductSlug()
+			if tt.ExpErrSubstring != "" {
+				require.ErrorContains(t, err, tt.ExpErrSubstring)
+			} else {
+				require.NoError(t, err)
+				assert.Equal(t, tt.ExpSlug, productSlug)
+			}
+		})
+	}
+}