apiserver/pkg/util/proxy/proxy.go

118 lines
3.4 KiB
Go

/*
Copyright 2017 The Kubernetes Authors.
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 proxy
import (
"fmt"
"math/rand"
"net"
"net/url"
"strconv"
"k8s.io/apimachinery/pkg/api/errors"
utilnet "k8s.io/apimachinery/pkg/util/net"
listersv1 "k8s.io/client-go/listers/core/v1"
"k8s.io/client-go/pkg/api/v1"
)
// ResourceLocation returns a URL to which one can send traffic for the specified service.
func ResolveEndpoint(services listersv1.ServiceLister, endpoints listersv1.EndpointsLister, namespace, id string) (*url.URL, error) {
// Allow ID as "svcname", "svcname:port", or "scheme:svcname:port".
svcScheme, svcName, portStr, valid := utilnet.SplitSchemeNamePort(id)
if !valid {
return nil, errors.NewBadRequest(fmt.Sprintf("invalid service request %q", id))
}
// If a port *number* was specified, find the corresponding service port name
if portNum, err := strconv.ParseInt(portStr, 10, 64); err == nil {
svc, err := services.Services(namespace).Get(svcName)
if err != nil {
return nil, err
}
found := false
for _, svcPort := range svc.Spec.Ports {
if int64(svcPort.Port) == portNum {
// use the declared port's name
portStr = svcPort.Name
found = true
break
}
}
if !found {
return nil, errors.NewServiceUnavailable(fmt.Sprintf("no service port %d found for service %q", portNum, svcName))
}
}
eps, err := endpoints.Endpoints(namespace).Get(svcName)
if err != nil {
return nil, err
}
if len(eps.Subsets) == 0 {
return nil, errors.NewServiceUnavailable(fmt.Sprintf("no endpoints available for service %q", svcName))
}
// Pick a random Subset to start searching from.
ssSeed := rand.Intn(len(eps.Subsets))
// Find a Subset that has the port.
for ssi := 0; ssi < len(eps.Subsets); ssi++ {
ss := &eps.Subsets[(ssSeed+ssi)%len(eps.Subsets)]
if len(ss.Addresses) == 0 {
continue
}
for i := range ss.Ports {
if ss.Ports[i].Name == portStr {
// Pick a random address.
ip := ss.Addresses[rand.Intn(len(ss.Addresses))].IP
port := int(ss.Ports[i].Port)
return &url.URL{
Scheme: svcScheme,
Host: net.JoinHostPort(ip, strconv.Itoa(port)),
}, nil
}
}
}
return nil, errors.NewServiceUnavailable(fmt.Sprintf("no endpoints available for service %q", id))
}
func ResolveCluster(services listersv1.ServiceLister, namespace, id string) (*url.URL, error) {
if len(id) == 0 {
return &url.URL{Scheme: "https"}, nil
}
destinationHost := id + "." + namespace + ".svc"
service, err := services.Services(namespace).Get(id)
if err != nil {
return &url.URL{
Scheme: "https",
Host: destinationHost,
}, nil
}
switch {
// use IP from a clusterIP for these service types
case service.Spec.Type == v1.ServiceTypeClusterIP,
service.Spec.Type == v1.ServiceTypeNodePort,
service.Spec.Type == v1.ServiceTypeLoadBalancer:
return &url.URL{
Scheme: "https",
Host: service.Spec.ClusterIP,
}, nil
}
return &url.URL{
Scheme: "https",
Host: destinationHost,
}, nil
}