Add support for generic plugin

Add support for generic kinds
We are currently using a known map to find the
group version resource for a kind.

Issue-ID: MULTICLOUD-350
Change-Id: I5a64f73760b73cf92b9a3fab8c22ad54e0a5f84f
Signed-off-by: Kiran Kamineni <kiran.k.kamineni@intel.com>

1 files changed, 128 insertions, 4 deletions

diff --git a/src/k8splugin/internal/app/client.go b/src/k8splugin/internal/app/client.go
index cb6f0eca..cd1ec8a2 100644
--- a/src/k8splugin/internal/app/client.go
+++ b/src/k8splugin/internal/app/client.go
@@ -21,13 +21,26 @@ import (
 	utils "k8splugin/internal"
 
 	pkgerrors "github.com/pkg/errors"
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/client-go/discovery"
+	"k8s.io/client-go/dynamic"
 	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/restmapper"
 	"k8s.io/client-go/tools/clientcmd"
 	"k8s.io/helm/pkg/tiller"
 )
 
+// KubernetesResource is the interface that is implemented
+type KubernetesResource interface {
+	Create(yamlFilePath string, namespace string, client *KubernetesClient) (string, error)
+	Delete(kind string, name string, namespace string, client *KubernetesClient) error
+}
+
 type KubernetesClient struct {
-	clientSet *kubernetes.Clientset
+	clientSet      *kubernetes.Clientset
+	dynamicClient  dynamic.Interface
+	discoverClient *discovery.DiscoveryClient
+	restMapper     meta.RESTMapper
 }
 
 // GetKubeClient loads the Kubernetes configuation values stored into the local configuration file
@@ -46,6 +59,16 @@ func (k *KubernetesClient) init(configPath string) error {
 		return err
 	}
 
+	k.dynamicClient, err = dynamic.NewForConfig(config)
+	if err != nil {
+		return pkgerrors.Wrap(err, "Creating dynamic client")
+	}
+
+	k.discoverClient, err = discovery.NewDiscoveryClientForConfig(config)
+	if err != nil {
+		return pkgerrors.Wrap(err, "Creating discovery client")
+	}
+
 	return nil
 }
 
@@ -82,6 +105,50 @@ func (k *KubernetesClient) ensureNamespace(namespace string) error {
 	return nil
 }
 
+func (k *KubernetesClient) createGeneric(kind string, files []string, namespace string) ([]string, error) {
+
+	log.Println("Processing items of Kind: " + kind)
+
+	//Check if have the mapper before loading the plugin
+	err := k.updateMapper()
+	if err != nil {
+		return nil, pkgerrors.Wrap(err, "Unable to create RESTMapper")
+	}
+
+	pluginObject, ok := utils.LoadedPlugins["generic"]
+	if !ok {
+		return nil, pkgerrors.New("No generic plugin found")
+	}
+
+	symbol, err := pluginObject.Lookup("ExportedVariable")
+	if err != nil {
+		return nil, pkgerrors.Wrap(err, "No ExportedVariable symbol found")
+	}
+
+	genericPlugin, ok := symbol.(KubernetesResource)
+	if !ok {
+		return nil, pkgerrors.New("ExportedVariable is not KubernetesResource type")
+	}
+
+	//Iterate over each file of a particular kind here
+	var resourcesCreated []string
+	for _, f := range files {
+		if _, err := os.Stat(f); os.IsNotExist(err) {
+			return nil, pkgerrors.New("File " + f + "does not exists")
+		}
+
+		log.Println("Processing file: " + f)
+
+		name, err := genericPlugin.Create(f, namespace, k)
+		if err != nil {
+			return nil, pkgerrors.Wrap(err, "Error in generic plugin")
+		}
+
+		resourcesCreated = append(resourcesCreated, name)
+	}
+	return resourcesCreated, nil
+}
+
 func (k *KubernetesClient) createKind(kind string, files []string, namespace string) ([]string, error) {
 
 	log.Println("Processing items of Kind: " + kind)
@@ -103,7 +170,8 @@ func (k *KubernetesClient) createKind(kind string, files []string, namespace str
 
 		typePlugin, ok := utils.LoadedPlugins[strings.ToLower(kind)]
 		if !ok {
-			return nil, pkgerrors.New("No plugin for kind " + kind + " found")
+			log.Println("No plugin for kind " + kind + " found. Using generic Plugin")
+			return k.createGeneric(kind, files, namespace)
 		}
 
 		symCreateResourceFunc, err := typePlugin.Lookup("Create")
@@ -163,17 +231,47 @@ func (k *KubernetesClient) createResources(resMap map[string][]string,
 	return createdResourceMap, nil
 }
 
+func (k *KubernetesClient) deleteGeneric(kind string, resources []string, namespace string) error {
+	log.Println("Deleting items of Kind: " + kind)
+
+	pluginObject, ok := utils.LoadedPlugins["generic"]
+	if !ok {
+		return pkgerrors.New("No generic plugin found")
+	}
+
+	symbol, err := pluginObject.Lookup("ExportedVariable")
+	if err != nil {
+		return pkgerrors.Wrap(err, "No ExportedVariable symbol found")
+	}
+
+	//Assert that it implements the KubernetesResource
+	genericPlugin, ok := symbol.(KubernetesResource)
+	if !ok {
+		return pkgerrors.New("ExportedVariable is not KubernetesResource type")
+	}
+
+	for _, res := range resources {
+		err = genericPlugin.Delete(kind, res, namespace, k)
+		if err != nil {
+			return pkgerrors.Wrap(err, "Error in generic plugin")
+		}
+	}
+
+	return nil
+}
+
 func (k *KubernetesClient) deleteKind(kind string, resources []string, namespace string) error {
 	log.Println("Deleting items of Kind: " + kind)
 
 	typePlugin, ok := utils.LoadedPlugins[strings.ToLower(kind)]
 	if !ok {
-		return pkgerrors.New("No plugin for resource " + kind + " found")
+		log.Println("No plugin for kind " + kind + " found. Using generic Plugin")
+		return k.deleteGeneric(kind, resources, namespace)
 	}
 
 	symDeleteResourceFunc, err := typePlugin.Lookup("Delete")
 	if err != nil {
-		return pkgerrors.Wrap(err, "Error fetching "+kind+" plugin")
+		return pkgerrors.Wrap(err, "Error findinf Delete symbol in plugin")
 	}
 
 	for _, res := range resources {
@@ -198,3 +296,29 @@ func (k *KubernetesClient) deleteResources(resMap map[string][]string, namespace
 
 	return nil
 }
+
+func (k *KubernetesClient) updateMapper() error {
+	//Create restMapper if not already done
+	if k.restMapper != nil {
+		return nil
+	}
+
+	groupResources, err := restmapper.GetAPIGroupResources(k.discoverClient)
+	if err != nil {
+		return pkgerrors.Wrap(err, "Get GroupResources")
+	}
+
+	k.restMapper = restmapper.NewDiscoveryRESTMapper(groupResources)
+	return nil
+}
+
+//GetMapper returns the RESTMapper that was created for this client
+func (k *KubernetesClient) GetMapper() meta.RESTMapper {
+	return k.restMapper
+}
+
+//GetDynamicClient returns the dynamic client that is needed for
+//unstructured REST calls to the apiserver
+func (k *KubernetesClient) GetDynamicClient() dynamic.Interface {
+	return k.dynamicClient
+}