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>

4 files changed, 239 insertions, 5 deletions

diff --git a/src/k8splugin/go.mod b/src/k8splugin/go.mod
index 29a10ecb..00ee2c8e 100644
--- a/src/k8splugin/go.mod
+++ b/src/k8splugin/go.mod
@@ -75,7 +75,7 @@ require (
 	gopkg.in/square/go-jose.v2 v2.2.2 // indirect
 	gopkg.in/yaml.v2 v2.2.1
 	k8s.io/api v0.0.0-20181126151915-b503174bad59
-	k8s.io/apiextensions-apiserver v0.0.0-20181126155829-0cd23ebeb688 // indirect
+	k8s.io/apiextensions-apiserver v0.0.0-20181126155829-0cd23ebeb688
 	k8s.io/apimachinery v0.0.0-20181126123746-eddba98df674
 	k8s.io/apiserver v0.0.0-20181126153457-92fdef3a232a // indirect
 	k8s.io/cli-runtime v0.0.0-20190107235426-31214e12222d // indirect
diff --git a/src/k8splugin/go.sum b/src/k8splugin/go.sum
index f22fe8da..e5f34549 100644
--- a/src/k8splugin/go.sum
+++ b/src/k8splugin/go.sum
@@ -257,6 +257,7 @@ k8s.io/client-go v9.0.0+incompatible h1:/PdJjifJTjMFe0G4ESclZDcwF1+bFePTJ2xf+MXj
 k8s.io/client-go v9.0.0+incompatible/go.mod h1:7vJpHMYJwNQCWgzmNV+VYUl1zCObLyodBc8nIyt8L5s=
 k8s.io/client-go v10.0.0+incompatible h1:h3fciHPG0O5QEzATTFoRw/YGtDsU6pxrMrAhxiTtcq0=
 k8s.io/client-go v10.0.0+incompatible/go.mod h1:7vJpHMYJwNQCWgzmNV+VYUl1zCObLyodBc8nIyt8L5s=
+k8s.io/client-go v11.0.0+incompatible h1:X3ykd+Z4G8MojP9TVDOR+h/IrpYJEolfR8W2B/FGKrk=
 k8s.io/helm v2.12.1+incompatible h1:Fw6it7ALJfqbbX95U3is3aswD6E8nh4aUYtvgzfna8A=
 k8s.io/helm v2.12.1+incompatible/go.mod h1:LZzlS4LQBHfciFOurYBFkCMTaZ0D1l+p0teMg7TSULI=
 k8s.io/helm v2.12.2+incompatible h1:vtddbkiGNMOd8maDDZDc111Rm9E5JeeNWDndows18i8=
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
+}
diff --git a/src/k8splugin/plugins/generic/plugin.go b/src/k8splugin/plugins/generic/plugin.go
new file mode 100644
index 00000000..b0cf609c
--- /dev/null
+++ b/src/k8splugin/plugins/generic/plugin.go
@@ -0,0 +1,109 @@
+/*
+Copyright 2018 Intel Corporation.
+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 (
+	"log"
+
+	pkgerrors "github.com/pkg/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/client-go/kubernetes/scheme"
+
+	utils "k8splugin/internal"
+	"k8splugin/internal/app"
+)
+
+type genericPlugin struct {
+}
+
+var kindToGVRMap = map[string]schema.GroupVersionResource{
+	"ConfigMap":   schema.GroupVersionResource{Group: "", Version: "v1", Resource: "configmaps"},
+	"StatefulSet": schema.GroupVersionResource{Group: "apps", Version: "v1", Resource: "statefulsets"},
+	"Job":         schema.GroupVersionResource{Group: "batch", Version: "v1", Resource: "jobs"},
+	"Pod":         schema.GroupVersionResource{Group: "", Version: "v1", Resource: "pods"},
+	"DaemonSet":   schema.GroupVersionResource{Group: "apps", Version: "v1", Resource: "daemonsets"},
+	"CustomResourceDefinition": schema.GroupVersionResource{
+		Group: "apiextensions.k8s.io", Version: "v1beta1", Resource: "customresourcedefinitions",
+	},
+}
+
+// Create deployment object in a specific Kubernetes cluster
+func (g genericPlugin) Create(yamlFilePath string, namespace string, client *app.KubernetesClient) (string, error) {
+	if namespace == "" {
+		namespace = "default"
+	}
+
+	//Decode the yaml file to create a runtime.Object
+	obj, err := utils.DecodeYAML(yamlFilePath, nil)
+	if err != nil {
+		return "", pkgerrors.Wrap(err, "Decode deployment object error")
+	}
+
+	//Convert the runtime.Object to an unstructured Object
+	unstruct := &unstructured.Unstructured{}
+	err = scheme.Scheme.Convert(obj, unstruct, nil)
+	if err != nil {
+		return "", pkgerrors.Wrap(err, "Converting to unstructured object")
+	}
+
+	dynClient := client.GetDynamicClient()
+	mapper := client.GetMapper()
+
+	gvk := unstruct.GroupVersionKind()
+	mapping, err := mapper.RESTMapping(schema.GroupKind{Group: gvk.Group, Kind: gvk.Kind}, gvk.Version)
+	if err != nil {
+		return "", pkgerrors.Wrap(err, "Mapping kind to resource error")
+	}
+
+	gvr := mapping.Resource
+
+	createdObj, err := dynClient.Resource(gvr).Namespace(namespace).Create(unstruct, metav1.CreateOptions{})
+	if err != nil {
+		return "", pkgerrors.Wrap(err, "Create object error")
+	}
+
+	return createdObj.GetName(), nil
+}
+
+// Delete an existing deployment hosted in a specific Kubernetes cluster
+func (g genericPlugin) Delete(kind string, name string, namespace string, client *app.KubernetesClient) error {
+	if namespace == "" {
+		namespace = "default"
+	}
+
+	deletePolicy := metav1.DeletePropagationForeground
+	opts := &metav1.DeleteOptions{
+		PropagationPolicy: &deletePolicy,
+	}
+
+	dynClient := client.GetDynamicClient()
+	gvr, ok := kindToGVRMap[kind]
+	if !ok {
+		return pkgerrors.New("GVR not found for: " + kind)
+	}
+
+	log.Printf("Using gvr: %s, %s, %s", gvr.Group, gvr.Version, gvr.Resource)
+
+	err := dynClient.Resource(gvr).Namespace(namespace).Delete(name, opts)
+	if err != nil {
+		return pkgerrors.Wrap(err, "Delete object error")
+	}
+
+	return nil
+}
+
+// ExportedVariable is what we will look for when calling the generic plugin
+var ExportedVariable genericPlugin