karmada/pkg/search/proxy/cluster_proxy.go

126 lines
3.6 KiB
Go

package proxy
import (
"bytes"
"context"
"fmt"
"io"
"io/ioutil"
"net/http"
"path"
corev1 "k8s.io/api/core/v1"
apierrors "k8s.io/apimachinery/pkg/api/errors"
"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
"k8s.io/apimachinery/pkg/runtime/schema"
"k8s.io/apiserver/pkg/endpoints/request"
"k8s.io/apiserver/pkg/registry/rest"
listcorev1 "k8s.io/client-go/listers/core/v1"
clusterlisters "github.com/karmada-io/karmada/pkg/generated/listers/cluster/v1alpha1"
"github.com/karmada-io/karmada/pkg/search/proxy/store"
"github.com/karmada-io/karmada/pkg/util/proxy"
)
// clusterProxy proxy to member clusters
type clusterProxy struct {
store store.Cache
clusterLister clusterlisters.ClusterLister
secretLister listcorev1.SecretLister
}
func newClusterProxy(store store.Cache, clusterLister clusterlisters.ClusterLister, secretLister listcorev1.SecretLister) *clusterProxy {
return &clusterProxy{
store: store,
clusterLister: clusterLister,
secretLister: secretLister,
}
}
func (c *clusterProxy) connect(ctx context.Context, requestInfo *request.RequestInfo, gvr schema.GroupVersionResource, proxyPath string, responder rest.Responder) (http.Handler, error) {
if requestInfo.Verb == "create" {
return nil, apierrors.NewMethodNotSupported(gvr.GroupResource(), requestInfo.Verb)
}
_, clusterName, err := c.store.GetResourceFromCache(ctx, gvr, requestInfo.Namespace, requestInfo.Name)
if err != nil {
return nil, err
}
h, err := c.connectCluster(ctx, clusterName, proxyPath, responder)
if err != nil {
return nil, err
}
if requestInfo.Verb != "update" {
return h, nil
}
// Objects get by client via proxy are edited some fields, different from objets in member clusters.
// So before update, we shall recover these fields.
return http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
if err = modifyRequest(req, clusterName); err != nil {
responder.Error(err)
return
}
h.ServeHTTP(rw, req)
}), nil
}
func (c *clusterProxy) connectCluster(ctx context.Context, clusterName string, proxyPath string, responder rest.Responder) (http.Handler, error) {
cluster, err := c.clusterLister.Get(clusterName)
if err != nil {
return nil, err
}
location, transport, err := proxy.Location(cluster.Name, cluster.Spec.APIEndpoint, cluster.Spec.ProxyURL)
if err != nil {
return nil, err
}
location.Path = path.Join(location.Path, proxyPath)
secretGetter := func(context.Context, string) (*corev1.Secret, error) {
if cluster.Spec.ImpersonatorSecretRef == nil {
return nil, fmt.Errorf("the impersonatorSecretRef of cluster %s is nil", cluster.Name)
}
return c.secretLister.Secrets(cluster.Spec.ImpersonatorSecretRef.Namespace).Get(cluster.Spec.ImpersonatorSecretRef.Name)
}
return proxy.ConnectCluster(ctx, cluster.Name, location, transport, responder, secretGetter)
}
func modifyRequest(req *http.Request, cluster string) error {
if req.ContentLength == 0 {
return nil
}
body := bytes.NewBuffer(make([]byte, 0, req.ContentLength))
_, err := io.Copy(body, req.Body)
if err != nil {
return err
}
_ = req.Body.Close()
defer func() {
req.Body = ioutil.NopCloser(body)
req.ContentLength = int64(body.Len())
}()
obj := &unstructured.Unstructured{}
_, _, err = unstructured.UnstructuredJSONScheme.Decode(body.Bytes(), nil, obj)
if err != nil {
// ignore error
return nil
}
changed := false
changed = store.RemoveCacheSourceAnnotation(obj) || changed
changed = store.RecoverClusterResourceVersion(obj, cluster) || changed
if changed {
// write changed object into body
body.Reset()
return unstructured.UnstructuredJSONScheme.Encode(obj, body)
}
return nil
}