forked from kubernetes/minikube
/
loadbalancer_patcher.go
162 lines (140 loc) · 5.18 KB
/
loadbalancer_patcher.go
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/*
Copyright 2018 The Kubernetes Authors All rights reserved.
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 tunnel
import (
"fmt"
"github.com/golang/glog"
core_v1 "k8s.io/api/core/v1"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
k8s_types "k8s.io/apimachinery/pkg/types"
"k8s.io/client-go/kubernetes/typed/core/v1"
"k8s.io/client-go/rest"
)
//requestSender is an interface exposed for testing what requests are sent through the k8s REST client
type requestSender interface {
send(request *rest.Request) ([]byte, error)
}
//patchConverter is an interface exposed for testing what patches are sent through the k8s REST client
type patchConverter interface {
convert(restClient rest.Interface, patch *Patch) *rest.Request
}
//loadBalancerEmulator is the main struct for emulating the loadbalancer behavior. it sets the ingress to the cluster IP
type loadBalancerEmulator struct {
coreV1Client v1.CoreV1Interface
requestSender requestSender
patchConverter patchConverter
}
func (l *loadBalancerEmulator) PatchServices() ([]string, error) {
return l.applyOnLBServices(func(restClient rest.Interface, svc core_v1.Service) ([]byte, error) {
return l.updateService(restClient, svc)
})
}
func (l *loadBalancerEmulator) Cleanup() ([]string, error) {
return l.applyOnLBServices(func(restClient rest.Interface, svc core_v1.Service) ([]byte, error) {
return l.cleanupService(restClient, svc)
})
}
func (l *loadBalancerEmulator) applyOnLBServices(action func(restClient rest.Interface, svc core_v1.Service) ([]byte, error)) ([]string, error) {
services := l.coreV1Client.Services("")
serviceList, err := services.List(metav1.ListOptions{})
if err != nil {
return nil, err
}
restClient := l.coreV1Client.RESTClient()
var managedServices []string
for _, svc := range serviceList.Items {
if svc.Spec.Type != "LoadBalancer" {
glog.V(3).Infof("%s is not type LoadBalancer, skipping.", svc.Name)
continue
}
glog.Infof("%s is type LoadBalancer.", svc.Name)
managedServices = append(managedServices, svc.Name)
result, err := action(restClient, svc)
if err != nil {
glog.Errorf("%s", result)
glog.Errorf("error patching service %s/%s: %s", svc.Namespace, svc.Name, err)
continue
}
}
return managedServices, nil
}
func (l *loadBalancerEmulator) updateService(restClient rest.Interface, svc core_v1.Service) ([]byte, error) {
clusterIP := svc.Spec.ClusterIP
ingresses := svc.Status.LoadBalancer.Ingress
if len(ingresses) == 1 && ingresses[0].IP == clusterIP {
return nil, nil
}
glog.V(3).Infof("[%s] setting ClusterIP as the LoadBalancer Ingress", svc.Name)
jsonPatch := fmt.Sprintf(`[{"op": "add", "path": "/status/loadBalancer/ingress", "value": [ { "ip": "%s" } ] }]`, clusterIP)
patch := &Patch{
Type: k8s_types.JSONPatchType,
ResourceName: svc.Name,
NameSpaceSet: true,
NameSpace: svc.Namespace,
Subresource: "status",
Resource: "services",
BodyContent: jsonPatch,
}
request := l.patchConverter.convert(restClient, patch)
result, err := l.requestSender.send(request)
if err != nil {
glog.Errorf("error patching %s with IP %s: %s", svc.Name, clusterIP, err)
} else {
glog.Infof("Patched %s with IP %s", svc.Name, clusterIP)
}
return result, err
}
func (l *loadBalancerEmulator) cleanupService(restClient rest.Interface, svc core_v1.Service) ([]byte, error) {
ingresses := svc.Status.LoadBalancer.Ingress
if len(ingresses) == 0 {
return nil, nil
}
glog.V(3).Infof("[%s] cleanup: unset load balancer ingress", svc.Name)
jsonPatch := `[{"op": "remove", "path": "/status/loadBalancer/ingress" }]`
patch := &Patch{
Type: k8s_types.JSONPatchType,
ResourceName: svc.Name,
NameSpaceSet: true,
NameSpace: svc.Namespace,
Subresource: "status",
Resource: "services",
BodyContent: jsonPatch,
}
request := l.patchConverter.convert(restClient, patch)
result, err := l.requestSender.send(request)
glog.Infof("Removed load balancer ingress from %s.", svc.Name)
return result, err
}
func newLoadBalancerEmulator(corev1Client v1.CoreV1Interface) loadBalancerEmulator {
return loadBalancerEmulator{
coreV1Client: corev1Client,
requestSender: &defaultRequestSender{},
patchConverter: &defaultPatchConverter{},
}
}
type defaultPatchConverter struct{}
func (c *defaultPatchConverter) convert(restClient rest.Interface, patch *Patch) *rest.Request {
request := restClient.Patch(patch.Type)
request.Name(patch.ResourceName)
request.Resource(patch.Resource)
request.SubResource(patch.Subresource)
if patch.NameSpaceSet {
request.Namespace(patch.NameSpace)
}
request.Body([]byte(patch.BodyContent))
return request
}
type defaultRequestSender struct{}
func (r *defaultRequestSender) send(request *rest.Request) ([]byte, error) {
return request.Do().Raw()
}