karmada/pkg/estimator/client/service.go

60 lines
2.1 KiB
Go

package client
import (
"context"
"fmt"
"net"
corev1 "k8s.io/api/core/v1"
apierrors "k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/util/intstr"
"k8s.io/client-go/kubernetes"
)
// ResolveCluster parses Service resource content by itself.
// Fixes Issue https://github.com/karmada-io/karmada/issues/2487
// Modified from "k8s.io/apiserver/pkg/util/proxy/proxy.go:92 => func ResolveCluster"
func resolveCluster(kubeClient kubernetes.Interface, namespace, id string, port int32) (string, error) {
svc, err := kubeClient.CoreV1().Services(namespace).Get(context.TODO(), id, metav1.GetOptions{})
if err != nil {
if apierrors.IsNotFound(err) {
/*
* When Deploying Karmada in Host Kubernetes Cluster, the kubeClient will connect kube-apiserver
* of Karmada Control Plane, rather than of host cluster.
* But the Service resource is defined in Host Kubernetes Cluster. So we cannot get its content here.
* The best thing we can do is just glue host:port together, and try to connect to it.
*/
return net.JoinHostPort(id, fmt.Sprintf("%d", port)), nil
}
return "", err
}
if svc.Spec.Type != corev1.ServiceTypeExternalName {
// We only support ExternalName type here.
// See discussions in PR: https://github.com/karmada-io/karmada/pull/2574#discussion_r979539389
return "", fmt.Errorf("unsupported service type %q", svc.Spec.Type)
}
svcPort, err := findServicePort(svc, port)
if err != nil {
return "", err
}
if svcPort.TargetPort.Type != intstr.Int {
return "", fmt.Errorf("ExternalName service type should have int target port, "+
"current target port: %v", svcPort.TargetPort)
}
return net.JoinHostPort(svc.Spec.ExternalName, fmt.Sprintf("%d", svcPort.TargetPort.IntVal)), nil
}
// findServicePort finds the service port by name or numerically.
func findServicePort(svc *corev1.Service, port int32) (*corev1.ServicePort, error) {
for _, svcPort := range svc.Spec.Ports {
if svcPort.Port == port {
return &svcPort, nil
}
}
return nil, apierrors.NewServiceUnavailable(fmt.Sprintf("no service port %d found for service %q", port, svc.Name))
}