feat: add ability to load content from folders (#78)

* feat: add ability to load content from folders

* added folder handler and fixed error wrapping

* added lint fixes

cmd/file_handler.go

@@ -0,0 +1,30 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1"
+	"k8s.io/apimachinery/pkg/util/yaml"
+)
+
+type FileHandler struct {
+	location string
+}
+
+func (h *FileHandler) CRDs() ([]*v1beta1.CustomResourceDefinition, error) {
+	if _, err := os.Stat(h.location); os.IsNotExist(err) {
+		return nil, fmt.Errorf("file under '%s' does not exist", h.location)
+	}
+	content, err := os.ReadFile(h.location)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read file: %w", err)
+	}
+
+	crd := &v1beta1.CustomResourceDefinition{}
+	if err := yaml.Unmarshal(content, crd); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal into custom resource definition: %w", err)
+	}
+
+	return []*v1beta1.CustomResourceDefinition{crd}, nil
+}

cmd/folder_handler.go

@@ -0,0 +1,59 @@
+package cmd
+
+import (
+	"fmt"
+	"io/fs"
+	"os"
+	"path/filepath"
+
+	"k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1"
+	"k8s.io/apimachinery/pkg/util/yaml"
+)
+
+type FolderHandler struct {
+	location string
+}
+
+func (h *FolderHandler) CRDs() ([]*v1beta1.CustomResourceDefinition, error) {
+	if _, err := os.Stat(h.location); os.IsNotExist(err) {
+		return nil, fmt.Errorf("file under '%s' does not exist", h.location)
+	}
+
+	var crds []*v1beta1.CustomResourceDefinition
+
+	if err := filepath.Walk(h.location, func(path string, info fs.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if info.IsDir() {
+			return nil
+		}
+
+		if filepath.Ext(path) != ".yaml" {
+			fmt.Fprintln(os.Stderr, "skipping file "+path)
+
+			return nil
+		}
+
+		content, err := os.ReadFile(path)
+		if err != nil {
+			return fmt.Errorf("failed to read file: %w", err)
+		}
+
+		crd := &v1beta1.CustomResourceDefinition{}
+		if err := yaml.Unmarshal(content, crd); err != nil {
+			fmt.Fprintln(os.Stderr, "skipping none CRD file: "+path)
+
+			return nil //nolint:nilerr // intentional
+		}
+
+		crds = append(crds, crd)
+
+		return nil
+	}); err != nil {
+		return nil, fmt.Errorf("failed to walk the selected folder: %w", err)
+	}
+
+	return crds, nil
+}

cmd/generate.go

@@ -4,23 +4,30 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"net/http"
 	"os"
 	"path/filepath"
 
+	"github.com/Skarlso/crd-to-sample-yaml/pkg"
 	"github.com/spf13/cobra"
 	"k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1"
-	"k8s.io/apimachinery/pkg/util/yaml"
-
-	"github.com/Skarlso/crd-to-sample-yaml/pkg"
-	"github.com/Skarlso/crd-to-sample-yaml/pkg/fetcher"
 )
 
 const (
 	FormatHTML = "html"
 	FormatYAML = "yaml"
 )
 
+type rootArgs struct {
+	fileLocation   string
+	folderLocation string
+	url            string
+	output         string
+	format         string
+	stdOut         bool
+	comments       bool
+	minimal        bool
+}
+
 var (
 	// generateCmd is root for various `generate ...` commands.
 	generateCmd = &cobra.Command{
@@ -29,76 +36,100 @@ var (
 		RunE:  runGenerate,
 	}
 
-	fileLocation string
-	url          string
-	output       string
-	format       string
-	stdOut       bool
-	comments     bool
-	minimal      bool
+	args = &rootArgs{}
 )
 
+type Handler interface {
+	CRDs() ([]*v1beta1.CustomResourceDefinition, error)
+}
+
 func init() {
 	rootCmd.AddCommand(generateCmd)
 
 	f := generateCmd.PersistentFlags()
-	f.StringVarP(&fileLocation, "crd", "c", "", "The CRD file to generate a yaml from.")
-	f.StringVarP(&url, "url", "u", "", "If provided, will use this URL to fetch CRD YAML content from.")
-	f.StringVarP(&output, "output", "o", "", "The location of the output file. Default is next to the CRD.")
-	f.StringVarP(&format, "format", "f", FormatYAML, "The format in which to output. Default is YAML. Options are: yaml, html.")
-	f.BoolVarP(&stdOut, "stdout", "s", false, "If set, it will output the generated content to stdout.")
-	f.BoolVarP(&comments, "comments", "m", false, "If set, it will add descriptions as comments to each line where available.")
-	f.BoolVarP(&minimal, "minimal", "l", false, "If set, only the minimal required example yaml is generated.")
+	f.StringVarP(&args.fileLocation, "crd", "c", "", "The CRD file to generate a yaml from.")
+	f.StringVarP(&args.folderLocation, "folder", "r", "", "A folder from which to parse a series of CRDs.")
+	f.StringVarP(&args.url, "url", "u", "", "If provided, will use this URL to fetch CRD YAML content from.")
+	f.StringVarP(&args.output, "output", "o", "", "The location of the output file. Default is next to the CRD.")
+	f.StringVarP(&args.format, "format", "f", FormatYAML, "The format in which to output. Default is YAML. Options are: yaml, html.")
+	f.BoolVarP(&args.stdOut, "stdout", "s", false, "If set, it will output the generated content to stdout.")
+	f.BoolVarP(&args.comments, "comments", "m", false, "If set, it will add descriptions as comments to each line where available.")
+	f.BoolVarP(&args.minimal, "minimal", "l", false, "If set, only the minimal required example yaml is generated.")
 }
 
 func runGenerate(_ *cobra.Command, _ []string) error {
-	var (
-		content []byte
-		err     error
-		w       io.WriteCloser
-	)
-	if url != "" {
-		f := fetcher.NewFetcher(http.DefaultClient)
-		content, err = f.Fetch(url)
-		if err != nil {
-			return fmt.Errorf("failed to fetch content: %w", err)
-		}
-	} else {
-		if _, err := os.Stat(fileLocation); os.IsNotExist(err) {
-			return fmt.Errorf("file under '%s' does not exist", fileLocation)
+	crdHandler, err := constructHandler(args)
+	if err != nil {
+		return err
+	}
+
+	if args.format == FormatHTML {
+		if err := pkg.LoadTemplates(); err != nil {
+			return fmt.Errorf("failed to load templates: %w", err)
 		}
-		content, err = os.ReadFile(fileLocation)
+	}
+
+	// determine location of output
+	if args.output == "" {
+		loc, err := os.Executable()
 		if err != nil {
-			return fmt.Errorf("failed to read file: %w", err)
+			return fmt.Errorf("failed to determine executable location: %w", err)
 		}
+
+		args.output = filepath.Dir(loc)
 	}
 
-	crd := &v1beta1.CustomResourceDefinition{}
-	if err := yaml.Unmarshal(content, crd); err != nil {
-		return errors.New("failed to unmarshal into custom resource definition")
+	crds, err := crdHandler.CRDs()
+	if err != nil {
+		return fmt.Errorf("failed to load CRDs: %w", err)
 	}
 
-	if stdOut {
-		w = os.Stdout
-	} else {
-		if output == "" {
-			output = filepath.Dir(fileLocation)
+	var w io.WriteCloser
+
+	var errs []error //nolint:prealloc // nope
+	for _, crd := range crds {
+		if args.stdOut {
+			w = os.Stdout
+		} else {
+			outputLocation := filepath.Join(args.output, crd.Name+"_sample."+args.format)
+			// closed later during render
+			outputFile, err := os.Create(outputLocation)
+			if err != nil {
+				errs = append(errs, fmt.Errorf("failed to create file at: '%s': %w", outputLocation, err))
+
+				continue
+			}
+
+			w = outputFile
 		}
-		outputLocation := filepath.Join(output, crd.Name+"_sample."+format)
-		outputFile, err := os.Create(outputLocation)
-		if err != nil {
-			return fmt.Errorf("failed to create file at: '%s': %w", outputLocation, err)
+
+		if args.format == FormatHTML {
+			errs = append(errs, pkg.RenderContent(w, crd, args.comments, args.minimal))
+
+			continue
 		}
-		w = outputFile
+
+		errs = append(errs, pkg.Generate(crd, w, args.comments, args.minimal))
 	}
 
-	if format == FormatHTML {
-		if err := pkg.LoadTemplates(); err != nil {
-			return fmt.Errorf("failed to load templates: %w", err)
-		}
+	return errors.Join(errs...)
+}
+
+func constructHandler(args *rootArgs) (Handler, error) {
+	var crdHandler Handler
+
+	switch {
+	case args.fileLocation != "":
+		crdHandler = &FileHandler{location: args.fileLocation}
+	case args.folderLocation != "":
+		crdHandler = &FolderHandler{location: args.folderLocation}
+	case args.url != "":
+		crdHandler = &URLHandler{url: args.url}
+	}
 
-		return pkg.RenderContent(w, content, comments, minimal)
+	if crdHandler == nil {
+		return nil, errors.New("one of the flags (file, folder, url) must be set")
 	}
 
-	return pkg.Generate(crd, w, comments, minimal)
+	return crdHandler, nil
 }

cmd/url_handler.go

@@ -0,0 +1,33 @@
+package cmd
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/Skarlso/crd-to-sample-yaml/pkg/fetcher"
+	"k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1"
+	"k8s.io/apimachinery/pkg/util/yaml"
+)
+
+type URLHandler struct {
+	url string
+}
+
+func (h *URLHandler) CRDs() ([]*v1beta1.CustomResourceDefinition, error) {
+	client := http.DefaultClient
+	client.Timeout = 10 * time.Second
+
+	f := fetcher.NewFetcher(client)
+	content, err := f.Fetch(h.url)
+	if err != nil {
+		return nil, fmt.Errorf("failed to fetch content: %w", err)
+	}
+
+	crd := &v1beta1.CustomResourceDefinition{}
+	if err := yaml.Unmarshal(content, crd); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal into custom resource definition: %w", err)
+	}
+
+	return []*v1beta1.CustomResourceDefinition{crd}, nil
+}

pkg/create_html_output.go

@@ -3,6 +3,7 @@ package pkg
 import (
 	"bytes"
 	"embed"
+	"errors"
 	"fmt"
 	"html/template"
 	"io"
@@ -11,7 +12,6 @@ import (
 	"sort"
 
 	"k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1"
-	"k8s.io/apimachinery/pkg/util/yaml"
 )
 
 // Version wraps a top level version resource which contains the underlying openAPIV3Schema.
@@ -61,11 +61,13 @@ func LoadTemplates() error {
 }
 
 // RenderContent creates an HTML website from the CRD content.
-func RenderContent(w io.Writer, crdContent []byte, comments, minimal bool) error {
-	crd := &v1beta1.CustomResourceDefinition{}
-	if err := yaml.Unmarshal(crdContent, crd); err != nil {
-		return fmt.Errorf("failed to unmarshal into custom resource definition: %w", err)
-	}
+func RenderContent(w io.WriteCloser, crd *v1beta1.CustomResourceDefinition, comments, minimal bool) (err error) {
+	defer func() {
+		if cerr := w.Close(); cerr != nil {
+			err = errors.Join(err, cerr)
+		}
+	}()
+
 	versions := make([]Version, 0)
 	parser := NewParser(crd.Spec.Group, crd.Spec.Names.Kind, comments, minimal)
 

pkg/generate.go

@@ -22,6 +22,7 @@ func Generate(crd *v1beta1.CustomResourceDefinition, w io.WriteCloser, enableCom
 			err = errors.Join(err, cerr)
 		}
 	}()
+
 	parser := NewParser(crd.Spec.Group, crd.Spec.Names.Kind, enableComments, minimal)
 	for i, version := range crd.Spec.Versions {
 		if err := parser.ParseProperties(version.Name, w, version.Schema.OpenAPIV3Schema.Properties, RootRequiredFields); err != nil {