On disk fake client

pkg/manifestclient/encoding.go

@@ -0,0 +1,89 @@
+package manifestclient
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/serializer"
+)
+
+func individualFromList(objList *unstructured.UnstructuredList, name string) (*unstructured.Unstructured, error) {
+	individualKind := strings.TrimSuffix(objList.GetKind(), "List")
+
+	for _, obj := range objList.Items {
+		if obj.GetName() != name {
+			continue
+		}
+
+		ret := obj.DeepCopy()
+		ret.SetKind(individualKind)
+		return ret, nil
+	}
+
+	return nil, fmt.Errorf("not found in this list")
+}
+
+func readListFile(contentReader RawReader, path string) (*unstructured.UnstructuredList, error) {
+	content, err := contentReader.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("unable to read %q: %w", path, err)
+	}
+
+	return decodeListObj(content)
+}
+
+func readIndividualFile(contentReader RawReader, path string) (*unstructured.Unstructured, error) {
+	content, err := contentReader.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("unable to read %q: %w", path, err)
+	}
+
+	return decodeIndividualObj(content)
+}
+
+var localScheme = runtime.NewScheme()
+var codecs = serializer.NewCodecFactory(localScheme)
+
+func decodeIndividualObj(content []byte) (*unstructured.Unstructured, error) {
+	obj, _, err := codecs.UniversalDecoder().Decode(content, nil, &unstructured.Unstructured{})
+	if err != nil {
+		return nil, fmt.Errorf("unable to decode: %w", err)
+	}
+	return obj.(*unstructured.Unstructured), nil
+}
+
+func decodeListObj(content []byte) (*unstructured.UnstructuredList, error) {
+	obj, _, err := codecs.UniversalDecoder().Decode(content, nil, &unstructured.UnstructuredList{})
+	if err != nil {
+		return nil, fmt.Errorf("unable to decode: %w", err)
+	}
+	return obj.(*unstructured.UnstructuredList), nil
+}
+
+func serializeIndividualObjToJSON(obj *unstructured.Unstructured) (string, error) {
+	ret, err := json.MarshalIndent(obj.Object, "", "    ")
+	if err != nil {
+		return "", err
+	}
+	return string(ret) + "\n", nil
+}
+
+func serializeListObjToJSON(obj *unstructured.UnstructuredList) (string, error) {
+	ret, err := json.MarshalIndent(obj, "", "    ")
+	if err != nil {
+		return "", err
+	}
+	return string(ret) + "\n", nil
+}
+
+func serializeAPIResourceListToJSON(obj *metav1.APIResourceList) (string, error) {
+	ret, err := json.MarshalIndent(obj, "", "    ")
+	if err != nil {
+		return "", err
+	}
+	return string(ret) + "\n", nil
+}

pkg/manifestclient/get.go

@@ -0,0 +1,113 @@
+package manifestclient
+
+import (
+	"errors"
+	"fmt"
+	"io/fs"
+	"path/filepath"
+
+	apirequest "k8s.io/apiserver/pkg/endpoints/request"
+)
+
+// must-gather has a few different ways to store resources
+// 1. cluster-scoped-resource/group/resource/<name>.yaml
+// 2. cluster-scoped-resource/group/resource.yaml
+// 3. namespaces/<namespace>/group/resource/<name>.yaml
+// 4. namespaces/<namespace>/group/resource.yaml
+// we have to choose which to prefer and we should always prefer the #2 if it's available.
+// Keep in mind that to produce a cluster-scoped list of namespaced resources, you can need to navigate many namespaces.
+func (mrt *manifestRoundTripper) get(requestInfo *apirequest.RequestInfo) ([]byte, error) {
+	if len(requestInfo.Name) == 0 {
+		return nil, fmt.Errorf("name required for GET")
+	}
+	if len(requestInfo.Resource) == 0 {
+		return nil, fmt.Errorf("resource required for GET")
+	}
+	requiredAPIVersion := fmt.Sprintf("%s/%s", requestInfo.APIGroup, requestInfo.APIVersion)
+	if len(requestInfo.APIGroup) == 0 {
+		requiredAPIVersion = fmt.Sprintf("%s", requestInfo.APIVersion)
+	}
+
+	individualFilePath := individualFileLocation(requestInfo)
+	individualObj, individualErr := readIndividualFile(mrt.contentReader, individualFilePath)
+	switch {
+	case errors.Is(individualErr, fs.ErrNotExist):
+		// try for the list
+	case individualErr != nil:
+		return nil, fmt.Errorf("unable to read file: %w", individualErr)
+	default:
+		if individualObj.GetAPIVersion() != requiredAPIVersion {
+			return nil, fmt.Errorf("actual version %v does not match request %v", individualObj.GetAPIVersion(), requiredAPIVersion)
+		}
+		ret, err := serializeIndividualObjToJSON(individualObj)
+		if err != nil {
+			return nil, fmt.Errorf("failed to serialize %v: %v", individualFilePath, err)
+		}
+		return []byte(ret), nil
+	}
+
+	listFilePath := listFileLocation(requestInfo)
+	listObj, listErr := readListFile(mrt.contentReader, listFilePath)
+	switch {
+	case errors.Is(listErr, fs.ErrNotExist):
+		// we need this to be a not-found when sent back
+		return nil, newNotFound(requestInfo)
+
+	case listErr != nil:
+		return nil, fmt.Errorf("unable to read file: %w", listErr)
+	default:
+		obj, err := individualFromList(listObj, requestInfo.Name)
+		if obj == nil {
+			return nil, newNotFound(requestInfo)
+		}
+		if obj.GetAPIVersion() != requiredAPIVersion {
+			return nil, fmt.Errorf("actual version %v does not match request %v", obj.GetAPIVersion(), requiredAPIVersion)
+		}
+
+		ret, err := serializeIndividualObjToJSON(obj)
+		if err != nil {
+			return nil, fmt.Errorf("failed to serialize %v: %v", listFilePath, err)
+		}
+		return []byte(ret), nil
+	}
+}
+
+func individualFileLocation(requestInfo *apirequest.RequestInfo) string {
+	fileParts := []string{}
+
+	if len(requestInfo.Namespace) > 0 {
+		fileParts = append(fileParts, "namespaces", requestInfo.Namespace)
+	} else {
+		fileParts = append(fileParts, "cluster-scoped-resources")
+	}
+
+	if len(requestInfo.APIGroup) > 0 {
+		fileParts = append(fileParts, requestInfo.APIGroup)
+	} else {
+		fileParts = append(fileParts, "core")
+	}
+
+	fileParts = append(fileParts, requestInfo.Resource, fmt.Sprintf("%s.yaml", requestInfo.Name))
+
+	return filepath.Join(fileParts...)
+}
+
+func listFileLocation(requestInfo *apirequest.RequestInfo) string {
+	fileParts := []string{}
+
+	if len(requestInfo.Namespace) > 0 {
+		fileParts = append(fileParts, "namespaces", requestInfo.Namespace)
+	} else {
+		fileParts = append(fileParts, "cluster-scoped-resources")
+	}
+
+	if len(requestInfo.APIGroup) > 0 {
+		fileParts = append(fileParts, requestInfo.APIGroup)
+	} else {
+		fileParts = append(fileParts, "core")
+	}
+
+	fileParts = append(fileParts, fmt.Sprintf("%s.yaml", requestInfo.Resource))
+
+	return filepath.Join(fileParts...)
+}

pkg/manifestclient/group_resource_discovery.go

@@ -0,0 +1,192 @@
+package manifestclient
+
+import (
+	"errors"
+	"fmt"
+	"io/fs"
+	"path/filepath"
+	"strings"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	apirequest "k8s.io/apiserver/pkg/endpoints/request"
+)
+
+func (mrt *manifestRoundTripper) getGroupResourceDiscovery(requestInfo *apirequest.RequestInfo) ([]byte, error) {
+	if len(requestInfo.Path) == 0 {
+		return nil, fmt.Errorf("path required for group resource discovery")
+	}
+
+	apiResourceList := &metav1.APIResourceList{}
+
+	group, version, err := splitGroupVersionFromRequestPath(requestInfo.Path)
+	if err != nil {
+		return nil, fmt.Errorf("unable to split group/version from path: %w", err)
+	}
+
+	apiResourceList.GroupVersion = fmt.Sprintf("%s/%s", group, version)
+	if group == "core" {
+		apiResourceList.GroupVersion = version
+	}
+
+	// Map of resource name to APIResource.
+	apiResources := map[string]metav1.APIResource{}
+
+	clusterGroupPath := filepath.Join("cluster-scoped-resources", group)
+	clusterGroupDirEntries, err := mrt.contentReader.ReadDir(clusterGroupPath)
+	if err != nil && !errors.Is(err, fs.ErrNotExist) {
+		return nil, fmt.Errorf("unable to read directory: %w", err)
+	}
+
+	apiResourcesForClusterScope, err := getAPIResourcesFromNamespaceDirEntries(clusterGroupDirEntries, mrt.contentReader, group, version, clusterGroupPath, false /* cluster-scoped */)
+	if err != nil {
+		return nil, fmt.Errorf("unable to get resources from cluster-scoped directory: %w", err)
+	}
+	for resourceName, apiResource := range apiResourcesForClusterScope {
+		apiResources[resourceName] = apiResource
+	}
+
+	namespaceDirEntries, err := mrt.contentReader.ReadDir("namespaces")
+	if err != nil {
+		return nil, fmt.Errorf("unable to read directory: %w", err)
+	}
+	for _, namespaceDirEntry := range namespaceDirEntries {
+		if !namespaceDirEntry.IsDir() {
+			continue
+		}
+
+		namespaceGroupPath := filepath.Join("namespaces", namespaceDirEntry.Name(), group)
+		namespaceGroupDirEntries, err := mrt.contentReader.ReadDir(namespaceGroupPath)
+		if err != nil && !errors.Is(err, fs.ErrNotExist) {
+			return nil, fmt.Errorf("unable to read directory: %w", err)
+		} else if errors.Is(err, fs.ErrNotExist) {
+			// No resources for this namespace.
+			continue
+		}
+
+		apiResourcesForNamespace, err := getAPIResourcesFromNamespaceDirEntries(namespaceGroupDirEntries, mrt.contentReader, group, version, namespaceGroupPath, true /* namespaced */)
+		if err != nil {
+			return nil, fmt.Errorf("unable to get resources from namespace directory: %w", err)
+		}
+
+		for resourceName, apiResource := range apiResourcesForNamespace {
+			apiResources[resourceName] = apiResource
+		}
+	}
+
+	for _, apiResource := range apiResources {
+		apiResourceList.APIResources = append(apiResourceList.APIResources, apiResource)
+	}
+
+	ret, err := serializeAPIResourceListToJSON(apiResourceList)
+	if err != nil {
+		return nil, fmt.Errorf("failed to serialize group resource discovery: %v", err)
+	}
+	return []byte(ret), nil
+}
+
+func splitGroupVersionFromRequestPath(path string) (string, string, error) {
+	if path == "/api/v1" {
+		return "core", "v1", nil
+	}
+
+	parts := strings.Split(path, "/")
+	if len(parts) != 4 {
+		return "", "", fmt.Errorf("invalid path: %s", path)
+	}
+
+	return parts[2], parts[3], nil
+}
+
+func getResourceDirAPIServerListEntry(contentReader RawReader, groupPath, resourceName, group, version string, namespaced bool) (*metav1.APIResource, error) {
+	resourceDirEntries, err := contentReader.ReadDir(filepath.Join(groupPath, resourceName))
+	if err != nil {
+		return nil, fmt.Errorf("unable to read directory: %w", err)
+	}
+	for _, fileEntry := range resourceDirEntries {
+		if !strings.HasSuffix(fileEntry.Name(), ".yaml") {
+			// There shouldn't be anything that hits this, but ignore it if there is.
+			continue
+		}
+
+		individualObj, individualErr := readIndividualFile(contentReader, filepath.Join(groupPath, resourceName, fileEntry.Name()))
+		if individualErr != nil {
+			return nil, fmt.Errorf("unable to read file: %w", individualErr)
+		}
+
+		groupVersion := fmt.Sprintf("%s/%s", group, version)
+		if group == "core" {
+			group = ""
+			groupVersion = version
+		}
+
+		if individualObj.GetAPIVersion() != groupVersion {
+			continue
+		}
+
+		// No point checking further, all files should produce the same APIResource.
+		return &metav1.APIResource{
+			Name:       resourceName,
+			Kind:       individualObj.GetKind(),
+			Group:      group,
+			Version:    version,
+			Namespaced: namespaced,
+			Verbs:      []string{"get", "list", "watch"},
+		}, nil
+	}
+
+	return nil, nil
+}
+
+func getAPIResourcesFromNamespaceDirEntries(dirEntries []fs.DirEntry, contentReader RawReader, group, version string, basePath string, namespaced bool) (map[string]metav1.APIResource, error) {
+	apiResources := map[string]metav1.APIResource{}
+	for _, dirEntry := range dirEntries {
+		// Directories are named after the resource and contain individual resources.
+		if dirEntry.IsDir() {
+			apiResource, err := getResourceDirAPIServerListEntry(contentReader, basePath, dirEntry.Name(), group, version, namespaced)
+			if err != nil {
+				return nil, fmt.Errorf("unable to get resource from directory: %w", err)
+			}
+			if apiResource != nil {
+				apiResources[dirEntry.Name()] = *apiResource
+			}
+		}
+
+		if !strings.HasSuffix(dirEntry.Name(), ".yaml") {
+			// There shouldn't be anything that hits this, but ignore it if there is.
+			continue
+		}
+
+		resourceName := strings.TrimSuffix(dirEntry.Name(), ".yaml")
+		if _, ok := apiResources[resourceName]; ok {
+			// We already have this resource.
+			continue
+		}
+
+		// Files are named after the resource and contain a list of resources.
+		listObj, err := readListFile(contentReader, filepath.Join(basePath, dirEntry.Name()))
+		if err != nil {
+			return nil, fmt.Errorf("unable to read list file: %w", err)
+		}
+
+		for _, obj := range listObj.Items {
+			if obj.GetAPIVersion() != fmt.Sprintf("%s/%s", group, version) {
+				continue
+			}
+
+			apiResources[resourceName] = metav1.APIResource{
+				Name:       resourceName,
+				Kind:       obj.GetKind(),
+				Group:      group,
+				Version:    version,
+				Namespaced: namespaced,
+				Verbs:      []string{"get", "list", "watch"},
+			}
+
+			// Once we find a resource in the expected group/version, we can break.
+			// Anything else would produce the same APIResource.
+			break
+		}
+	}
+
+	return apiResources, nil
+}