added substitutes template generation from FBC

Signed-off-by: grokspawn <[email protected]>

Author: grokspawn

alpha/template/converter/converter.go

@@ -9,22 +9,34 @@ import (
 	"sigs.k8s.io/yaml"
 
 	"github.com/operator-framework/operator-registry/alpha/template/basic"
+	"github.com/operator-framework/operator-registry/alpha/template/substitutes"
 	"github.com/operator-framework/operator-registry/pkg/image"
 )
 
 type Converter struct {
-	FbcReader    io.Reader
-	OutputFormat string
-	Registry     image.Registry
+	FbcReader               io.Reader
+	OutputFormat            string
+	Registry                image.Registry
+	DestinationTemplateType string // TODO: when we have a template factory, we can pass it here
 }
 
 func (c *Converter) Convert() error {
-	bt, err := basic.FromReader(c.FbcReader)
-	if err != nil {
-		return err
+	var b []byte
+	switch c.DestinationTemplateType {
+	case "basic":
+		bt, err := basic.FromReader(c.FbcReader)
+		if err != nil {
+			return err
+		}
+		b, _ = json.MarshalIndent(bt, "", "    ")
+	case "substitutes":
+		st, err := substitutes.FromReader(c.FbcReader)
+		if err != nil {
+			return err
+		}
+		b, _ = json.MarshalIndent(st, "", "    ")
 	}
 
-	b, _ := json.MarshalIndent(bt, "", "    ")
 	if c.OutputFormat == "json" {
 		fmt.Fprintln(os.Stdout, string(b))
 	} else {

alpha/template/substitutes/substitutes.go

@@ -158,3 +158,26 @@ func (t Template) processSubstitution(ctx context.Context, cfg *declcfg.Declarat
 
 	return nil
 }
+
+// FromReader reads FBC from a reader and generates a BasicTemplate from it
+func FromReader(r io.Reader) (*SubstitutesForTemplate, error) {
+	var entries []*declcfg.Meta
+	if err := declcfg.WalkMetasReader(r, func(meta *declcfg.Meta, err error) error {
+		if err != nil {
+			return err
+		}
+
+		entries = append(entries, meta)
+		return nil
+	}); err != nil {
+		return nil, err
+	}
+
+	bt := &SubstitutesForTemplate{
+		Schema:        schema,
+		Entries:       entries,
+		Substitutions: []Substitute{},
+	}
+
+	return bt, nil
+}

cmd/opm/alpha/convert-template/convert.go

@@ -17,6 +17,7 @@ func NewCmd() *cobra.Command {
 	}
 	cmd.AddCommand(
 		newBasicConvertCmd(),
+		newSubstitutesConvertCmd(),
 	)
 	return cmd
 }
@@ -49,6 +50,49 @@ If no argument is specified or is '-' input is assumed from STDIN.
 			}
 
 			converter.FbcReader = reader
+			converter.DestinationTemplateType = "basic"
+			err = converter.Convert()
+			if err != nil {
+				return fmt.Errorf("converting: %v", err)
+			}
+
+			return nil
+		},
+	}
+	cmd.Flags().StringVarP(&output, "output", "o", "json", "Output format (json|yaml)")
+
+	return cmd
+}
+
+func newSubstitutesConvertCmd() *cobra.Command {
+	var (
+		converter converter.Converter
+		output    string
+	)
+	cmd := &cobra.Command{
+		Use:   "substitutes [<fbc-file> | -]",
+		Args:  cobra.MaximumNArgs(1),
+		Short: "Generate a substitutes template from existing FBC",
+		Long: `Generate a substitutes template from existing FBC.
+
+This command outputs a substitutes catalog template to STDOUT from input FBC.
+If no argument is specified or is '-' input is assumed from STDIN.
+`,
+		RunE: func(c *cobra.Command, args []string) error {
+			switch output {
+			case "yaml", "json":
+				converter.OutputFormat = output
+			default:
+				log.Fatalf("invalid --output value %q, expected (json|yaml)", output)
+			}
+
+			reader, name, err := util.OpenFileOrStdin(c, args)
+			if err != nil {
+				return fmt.Errorf("unable to open input: %q", name)
+			}
+
+			converter.FbcReader = reader
+			converter.DestinationTemplateType = "substitutes"
 			err = converter.Convert()
 			if err != nil {
 				return fmt.Errorf("converting: %v", err)