Add empty CRD description validator

Operator-SDK has alpha support for running external validators.
Validators are implemented as binaries that are given a path to bundle
and print the result of the validation to the standard out. More
information is available at
operator-framework/enhancements#98.

This commit adds in an external validator that errors when a CRD
specified in the bundle `ClusterServiceVersion` does not have a
description. This is enforced for both owned and required CRDs.

Signed-off-by: Ryan King <ryking@redhat.com>

cmd/validators/no-empty-crd-description/main.go

@@ -0,0 +1,96 @@
+// Copyright 2019 The Operator-SDK Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	apimanifests "github.com/operator-framework/api/pkg/manifests"
+	apierrors "github.com/operator-framework/api/pkg/validation/errors"
+	registrybundle "github.com/operator-framework/operator-registry/pkg/lib/bundle"
+	"github.com/operator-framework/operator-sdk/internal/registry"
+)
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Printf("usage: %s <bundle root>\n", os.Args[0])
+		os.Exit(1)
+	}
+
+	bundle, _, err := getBundleDataFromDir(os.Args[1])
+	if err != nil {
+		fmt.Printf("problem getting bundle [%s] data, %v\n", os.Args[1], err)
+		os.Exit(1)
+	}
+
+	var (
+		ownedCRDs    = bundle.CSV.Spec.CustomResourceDefinitions.Owned
+		requiredCRDs = bundle.CSV.Spec.CustomResourceDefinitions.Required
+		result       = apierrors.ManifestResult{
+			Name:     bundle.Name,
+			Warnings: []apierrors.Error{},
+			Errors:   make([]apierrors.Error, 0, len(ownedCRDs)+len(requiredCRDs)),
+		}
+		enc = json.NewEncoder(os.Stdout)
+	)
+
+	for _, crd := range append(ownedCRDs, requiredCRDs...) {
+		if crd.Description == "" {
+			result.Errors = append(result.Errors, makeEmptyCrdDescriptionError(crd.DisplayName))
+		}
+	}
+
+	enc.SetIndent("", "    ")
+	if err := enc.Encode(result); err != nil {
+		fmt.Printf("XXX ERROR: %v\n", err)
+	}
+}
+
+// getBundleDataFromDir returns the bundle object and associated metadata from dir, if any.
+func getBundleDataFromDir(dir string) (*apimanifests.Bundle, string, error) {
+	// Gather bundle metadata.
+	metadata, _, err := registry.FindBundleMetadata(dir)
+	if err != nil {
+		return nil, "", err
+	}
+	manifestsDirName, hasLabel := metadata.GetManifestsDir()
+	if !hasLabel {
+		manifestsDirName = registrybundle.ManifestsDir
+	}
+	manifestsDir := filepath.Join(dir, manifestsDirName)
+	// Detect mediaType.
+	mediaType, err := registrybundle.GetMediaType(manifestsDir)
+	if err != nil {
+		return nil, "", err
+	}
+	// Read the bundle.
+	bundle, err := apimanifests.GetBundleFromDir(manifestsDir)
+	if err != nil {
+		return nil, "", err
+	}
+	return bundle, mediaType, nil
+}
+
+func makeEmptyCrdDescriptionError(displayName string) apierrors.Error {
+	return apierrors.Error{
+		Type:     apierrors.ErrorFieldMissing,
+		Level:    apierrors.LevelError,
+		Field:    displayName,
+		BadValue: "",
+		Detail:   "CRD descriptions cannot be empty",
+	}
+}