linkerd2/controller/destination/server.go

152 lines
3.3 KiB
Go

package destination
import (
"fmt"
"net"
"strconv"
"strings"
common "github.com/runconduit/conduit/controller/gen/common"
pb "github.com/runconduit/conduit/controller/gen/proxy/destination"
"github.com/runconduit/conduit/controller/k8s"
"github.com/runconduit/conduit/controller/util"
log "github.com/sirupsen/logrus"
"google.golang.org/grpc"
)
type (
server struct {
endpoints *k8s.EndpointsWatcher
}
)
// The Destination service serves service discovery information to the proxy.
// This implementation supports the "k8s" destination scheme and expects
// destination paths to be of the form:
// <service>.<namespace>.svc.cluster.local:<port>
//
// If the port is omitted, 80 is used as a default. If the namespace is
// omitted, "default" is used as a default.append
//
// Addresses for the given destination are fetched from the Kubernetes Endpoints
// API.
func NewServer(addr, kubeconfig string, done chan struct{}) (*grpc.Server, net.Listener, error) {
clientSet, err := k8s.NewClientSet(kubeconfig)
if err != nil {
return nil, nil, err
}
endpoints := k8s.NewEndpointsWatcher(clientSet)
go endpoints.Run()
srv := &server{
endpoints: endpoints,
}
lis, err := net.Listen("tcp", addr)
if err != nil {
return nil, nil, err
}
s := util.NewGrpcServer()
pb.RegisterDestinationServer(s, srv)
go func() {
<-done
endpoints.Stop()
}()
return s, lis, nil
}
func (s *server) Get(dest *common.Destination, stream pb.Destination_GetServer) error {
log.Debugf("Get %v", dest)
if dest.Scheme != "k8s" {
err := fmt.Errorf("Unsupported scheme %v", dest.Scheme)
log.Error(err)
return err
}
hostPort := strings.Split(dest.Path, ":")
if len(hostPort) > 2 {
err := fmt.Errorf("Invalid destination %s", dest.Path)
log.Error(err)
return err
}
host := hostPort[0]
port := 80
if len(hostPort) == 2 {
var err error
port, err = strconv.Atoi(hostPort[1])
if err != nil {
err := fmt.Errorf("Invalid port %s", hostPort[1])
log.Error(err)
return err
}
}
// service.namespace.svc.cluster.local
domains := strings.Split(host, ".")
if len(domains) < 2 {
err := fmt.Errorf("not a service: %s", host)
log.Error(err)
return err
}
service := domains[0]
namespace := domains[1]
id := namespace + "/" + service
listener := endpointListener{stream: stream}
s.endpoints.Subscribe(id, uint32(port), listener)
<-stream.Context().Done()
s.endpoints.Unsubscribe(id, uint32(port), listener)
return nil
}
type endpointListener struct {
stream pb.Destination_GetServer
}
func (listener endpointListener) Update(add []common.TcpAddress, remove []common.TcpAddress) {
if len(add) > 0 {
update := &pb.Update{
Update: &pb.Update_Add{
Add: toWeightedAddrSet(add),
},
}
listener.stream.Send(update)
}
if len(remove) > 0 {
update := &pb.Update{
Update: &pb.Update_Remove{
Remove: toAddrSet(remove),
},
}
listener.stream.Send(update)
}
}
func toWeightedAddrSet(endpoints []common.TcpAddress) *pb.WeightedAddrSet {
addrs := make([]*pb.WeightedAddr, 0)
for i := range endpoints {
addrs = append(addrs, &pb.WeightedAddr{
Addr: &endpoints[i],
Weight: 1,
})
}
return &pb.WeightedAddrSet{Addrs: addrs}
}
func toAddrSet(endpoints []common.TcpAddress) *pb.AddrSet {
addrs := make([]*common.TcpAddress, 0)
for i := range endpoints {
addrs = append(addrs, &endpoints[i])
}
return &pb.AddrSet{Addrs: addrs}
}