add version api (#2127)

add cluster validation api

pkg/kapis/cluster/v1alpha1/handler.go

@@ -2,6 +2,7 @@ package v1alpha1
 
 import (
 	"bytes"
+	"encoding/json"
 	"fmt"
 	"github.com/emicklei/go-restful"
 	"io"
@@ -10,20 +11,30 @@ import (
 	"k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes"
 	v1 "k8s.io/client-go/listers/core/v1"
+	"k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/clientcmd"
 	"kubesphere.io/kubesphere/pkg/api"
 	"kubesphere.io/kubesphere/pkg/apis/cluster/v1alpha1"
 	clusterlister "kubesphere.io/kubesphere/pkg/client/listers/cluster/v1alpha1"
+	"kubesphere.io/kubesphere/pkg/version"
+	"net/http"
+	"net/url"
 	"strings"
+	"time"
 
 	"k8s.io/cli-runtime/pkg/printers"
 )
 
 const (
 	defaultAgentImage = "kubesphere/tower:v1.0"
+	defaultTimeout    = 5 * time.Second
 )
 
-var ErrClusterConnectionIsNotProxy = fmt.Errorf("cluster is not using proxy connection")
+var errClusterConnectionIsNotProxy = fmt.Errorf("cluster is not using proxy connection")
+var errNon200Response = fmt.Errorf("non-200 response returned from endpoint")
+var errInvalidResponse = fmt.Errorf("invalid response from kubesphere apiserver")
 
 type handler struct {
 	serviceLister v1.ServiceLister
@@ -87,7 +98,6 @@ func (h *handler) GenerateAgentDeployment(request *restful.Request, response *re
 	}
 
 	response.Write(buf.Bytes())
-
 }
 
 //
@@ -138,7 +148,7 @@ func (h *handler) populateProxyAddress() error {
 func (h *handler) generateDefaultDeployment(cluster *v1alpha1.Cluster, w io.Writer) error {
 
 	if cluster.Spec.Connection.Type == v1alpha1.ConnectionTypeDirect {
-		return ErrClusterConnectionIsNotProxy
+		return errClusterConnectionIsNotProxy
 	}
 
 	agent := appsv1.Deployment{
@@ -174,6 +184,7 @@ func (h *handler) generateDefaultDeployment(cluster *v1alpha1.Cluster, w io.Writ
 								fmt.Sprintf("--name=%s", cluster.Name),
 								fmt.Sprintf("--token=%s", cluster.Spec.Connection.Token),
 								fmt.Sprintf("--proxy-server=%s", h.proxyAddress),
+								fmt.Sprintf("--keepalive=30s"),
 								fmt.Sprintf("--kubesphere-service=ks-apiserver.kubesphere-system.svc:80"),
 								fmt.Sprintf("--kubernetes-service=kubernetes.default.svc:443"),
 							},
@@ -198,3 +209,102 @@ func (h *handler) generateDefaultDeployment(cluster *v1alpha1.Cluster, w io.Writ
 
 	return h.yamlPrinter.PrintObj(&agent, w)
 }
+
+// ValidateCluster validate cluster kubeconfig and kubesphere apiserver address, check their accessibility
+func (h *handler) ValidateCluster(request *restful.Request, response *restful.Response) {
+	var cluster v1alpha1.Cluster
+
+	err := request.ReadEntity(&cluster)
+	if err != nil {
+		api.HandleBadRequest(response, request, err)
+		return
+	}
+
+	if cluster.Spec.Connection.Type != v1alpha1.ConnectionTypeDirect {
+		api.HandleBadRequest(response, request, fmt.Errorf("cluster connection type is not direct"))
+		return
+	}
+
+	if len(cluster.Spec.Connection.KubeConfig) == 0 || len(cluster.Spec.Connection.KubeSphereAPIEndpoint) == 0 {
+		api.HandleBadRequest(response, request, fmt.Errorf("cluster kubeconfig and kubesphere endpoint should not be empty"))
+		return
+	}
+
+	err = validateKubeConfig(cluster.Spec.Connection.KubeConfig)
+	if err != nil {
+		api.HandleBadRequest(response, request, err)
+		return
+	}
+
+	_, err = validateKubeSphereAPIServer(cluster.Spec.Connection.KubeSphereAPIEndpoint)
+	if err != nil {
+		api.HandleBadRequest(response, request, fmt.Errorf("unable validate kubesphere endpoint, %v", err))
+		return
+	}
+
+	response.WriteHeader(http.StatusOK)
+}
+
+// validateKubeConfig takes base64 encoded kubeconfig and check its validity
+func validateKubeConfig(kubeconfig []byte) error {
+	config, err := loadKubeConfigFromBytes(kubeconfig)
+	if err != nil {
+		return err
+	}
+
+	config.Timeout = defaultTimeout
+
+	clientSet, err := kubernetes.NewForConfig(config)
+	if err != nil {
+		return err
+	}
+
+	_, err = clientSet.Discovery().ServerVersion()
+
+	return err
+}
+
+func loadKubeConfigFromBytes(kubeconfig []byte) (*rest.Config, error) {
+	clientConfig, err := clientcmd.NewClientConfigFromBytes(kubeconfig)
+	if err != nil {
+		return nil, err
+	}
+
+	config, err := clientConfig.ClientConfig()
+	if err != nil {
+		return nil, err
+	}
+
+	return config, nil
+}
+
+// validateKubeSphereAPIServer uses version api to check the accessibility
+func validateKubeSphereAPIServer(ksEndpoint string) (*version.Info, error) {
+	_, err := url.Parse(ksEndpoint)
+	if err != nil {
+		return nil, err
+	}
+
+	path := fmt.Sprintf("%s/kapis/version", ksEndpoint)
+
+	client := http.Client{
+		Timeout: defaultTimeout,
+	}
+
+	response, err := client.Get(path)
+	if err != nil {
+		return nil, err
+	}
+
+	if response.StatusCode != http.StatusOK {
+		return nil, errNon200Response
+	}
+
+	ver := version.Info{}
+	err = json.NewDecoder(response.Body).Decode(&ver)
+	if err != nil {
+		return nil, errInvalidResponse
+	}
+
+	return &ver, nil
+}