Read manifest from GitHub url or the file system

cmd/app/cmd.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/gardener/docforge/pkg/api"
 	"github.com/gardener/docforge/pkg/hugo"
+	"github.com/gardener/docforge/pkg/resourcehandlers"
 	"github.com/spf13/cobra"
 	"k8s.io/klog/v2"
 )
@@ -43,15 +44,24 @@ func NewCommand(ctx context.Context, cancel context.CancelFunc) *cobra.Command {
 	flags := &cmdFlags{}
 	cmd := &cobra.Command{
 		Use:   "docforge",
-		Short: "Build documentation bundle",
+		Short: "Forge a documentation bundle",
 		RunE: func(cmd *cobra.Command, args []string) error {
 			cmd.SilenceUsage = true
+			var (
+				doc *api.Documentation
+				rhs []resourcehandlers.ResourceHandler
+				err error
+			)
 			options := NewOptions(flags)
-			doc := Manifest(flags.documentationManifestPath, flags.variables)
+			if rhs, err = initResourceHandlers(ctx, options.GitHubTokens, options.Metering); err != nil {
+				return err
+			}
+			if doc, err = manifest(ctx, flags.documentationManifestPath, rhs, flags.variables); err != nil {
+				return err
+			}
 			if err := api.ValidateManifest(doc); err != nil {
 				return err
 			}
-
 			reactor, err := NewReactor(ctx, options, doc.Links)
 			if err != nil {
 				return err
@@ -90,7 +100,7 @@ func (flags *cmdFlags) Configure(command *cobra.Command) {
 	command.Flags().StringVar(&flags.resourcesPath, "resources-download-path", "__resources",
 		"Resources download path.")
 	command.Flags().StringVar(&flags.ghOAuthToken, "github-oauth-token", "",
-		"GitHub personal token authorizing read access from GitHub.com repositories. For authorization credentials for multiple GitHub instances, see --gtihub-oauth-token-map")
+		"GitHub personal token authorizing read access from GitHub.com repositories. For authorization credentials for multiple GitHub instances, see --github-oauth-token-map")
 	command.Flags().StringToStringVar(&flags.ghOAuthTokens, "github-oauth-token-map", map[string]string{},
 		"GitHub personal tokens authorizing read access from repositories per GitHub instance. Note that if the GitHub token is already provided by `github-oauth-token` it will be overridden by it.")
 	command.Flags().StringVar(&flags.ghInfoDestination, "github-info-destination", "",

cmd/app/manifest.go

@@ -0,0 +1,58 @@
+// SPDX-FileCopyrightText: 2020 SAP SE or an SAP affiliate company and Gardener contributors
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package app
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"html/template"
+	"strings"
+
+	"github.com/gardener/docforge/pkg/api"
+	"github.com/gardener/docforge/pkg/resourcehandlers"
+)
+
+// Manifest reads the resource at uri, resolves it as template applying vars,
+// and finally parses it into api.Documentation model
+func manifest(ctx context.Context, uri string, resourceHandlers []resourcehandlers.ResourceHandler, vars map[string]string) (*api.Documentation, error) {
+	var (
+		docs    *api.Documentation
+		err     error
+		blob    []byte
+		handler resourcehandlers.ResourceHandler
+	)
+	uri = strings.TrimSpace(uri)
+	registry := resourcehandlers.NewRegistry(resourceHandlers...)
+	if handler = registry.Get(uri); handler == nil {
+		return nil, fmt.Errorf("no suitable reader found for %s. Is this path correct?", uri)
+	}
+	if blob, err = handler.Read(ctx, uri); err != nil {
+		return nil, err
+	}
+	blob, err = resolveVariables(blob, vars)
+	if err != nil {
+		panic(fmt.Sprintf("%v\n", err))
+	}
+	if docs, err = api.Parse(blob); err != nil {
+		panic(fmt.Sprintf("%v\n", err))
+	}
+	return docs, nil
+}
+
+func resolveVariables(manifestContent []byte, vars map[string]string) ([]byte, error) {
+	var (
+		tmpl *template.Template
+		err  error
+		b    bytes.Buffer
+	)
+	if tmpl, err = template.New("").Parse(string(manifestContent)); err != nil {
+		return nil, err
+	}
+	if err := tmpl.Execute(&b, vars); err != nil {
+		return nil, err
+	}
+	return b.Bytes(), nil
+}

pkg/resourcehandlers/github/github_resource_handler.go

@@ -327,9 +327,18 @@ func (gh *GitHub) Accept(uri string) bool {
 	if gh.acceptedHosts == nil {
 		return false
 	}
+	// Quick sanity check, preventing panic when trying to
+	// resolve relative paths in url.Parse
+	if !strings.HasPrefix(uri, "http") {
+		return false
+	}
 	if url, err = url.Parse(uri); err != nil {
 		return false
 	}
+	// check if this is a GitHub URL
+	if rl, err := parse(uri); rl == nil || err != nil {
+		return false
+	}
 	for _, s := range gh.acceptedHosts {
 		if url.Host == s {
 			return true