Create a new output mode for creating group and version combination

Author: admacleod

README.md

@@ -42,7 +42,7 @@ crd-ref-docs \
 ```
 
 Default output mode writes all data to a single output file. 
-You can choose between single mode and group mode by specifying the output mode. 
+You can choose between single mode, group mode, or version mode by specifying the output mode. 
 In group mode, separate files are created for each API group, ensuring that the specified output path is an existing directory.
 ```
 crd-ref-docs \
@@ -51,6 +51,14 @@ crd-ref-docs \
     --output-path=./docs \
     --output-mode=group
 ```
+In version mode, separate files are created for each API group and version combination, ensuring that the specified output path is an existing directory.
+```
+crd-ref-docs \
+    --source-path=$GOPATH/src/github.com/elastic/cloud-on-k8s/pkg/apis \
+    --config=config.yaml \
+    --output-path=./docs \
+    --output-mode=version
+```
 
 ### Configuration
 

config/config.go

@@ -63,8 +63,9 @@ type KnownType struct {
 }
 
 const (
-	OutputModeSingle = "single"
-	OutputModeGroup  = "group"
+	OutputModeSingle       = "single"
+	OutputModeGroup        = "group"
+	OutputModeGroupVersion = "version"
 )
 
 type Flags struct {

renderer/renderer.go

@@ -21,6 +21,7 @@ import (
 	"io/fs"
 	"os"
 	"path/filepath"
+	"strings"
 	"text/template"
 
 	"github.com/elastic/crd-ref-docs/config"
@@ -91,6 +92,24 @@ func renderTemplate(tmpl *template.Template, conf *config.Config, fileExtension
 				return err
 			}
 
+			if err := tmpl.ExecuteTemplate(file, mainTemplate, []types.GroupVersionDetails{gvd}); err != nil {
+				return err
+			}
+		}
+	case config.OutputModeGroupVersion:
+		for _, gvd := range gvds {
+			// To avoid filenames containing filepath separators, replace them with a non-separator value.
+			// Using the GroupVersionString is the core difference between this output mode and the regular
+			// group mode.
+			name := strings.NewReplacer("/", "-").Replace(gvd.GroupVersionString())
+
+			fileName := fmt.Sprintf("%s.%s", name, fileExtension)
+			file, err := createOutFile(conf.OutputPath, true, fileName)
+			defer file.Close()
+			if err != nil {
+				return err
+			}
+
 			if err := tmpl.ExecuteTemplate(file, mainTemplate, []types.GroupVersionDetails{gvd}); err != nil {
 				return err
 			}