linkerd2/controller/destination/server.go

144 lines
3.6 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 {
podsByIp k8s.PodIndex
resolvers []streamingDestinationResolver
enableTLS bool
}
// 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, k8sDNSZone string, enableTLS bool, done chan struct{}) (*grpc.Server, net.Listener, error) {
clientSet, err := k8s.NewClientSet(kubeconfig)
if err != nil {
return nil, nil, err
}
podsByIp, err := k8s.NewPodsByIp(clientSet)
if err != nil {
return nil, nil, err
}
err = podsByIp.Run()
if err != nil {
return nil, nil, err
}
endpointsWatcher := k8s.NewEndpointsWatcher(clientSet)
err = endpointsWatcher.Run()
if err != nil {
return nil, nil, err
}
resolvers, err := buildResolversList(k8sDNSZone, endpointsWatcher)
if err != nil {
return nil, nil, err
}
srv := server{
podsByIp: podsByIp,
resolvers: resolvers,
enableTLS: enableTLS,
}
lis, err := net.Listen("tcp", addr)
if err != nil {
return nil, nil, err
}
s := util.NewGrpcServer()
pb.RegisterDestinationServer(s, &srv)
go func() {
<-done
endpointsWatcher.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
}
}
return s.streamResolutionUsingCorrectResolverFor(host, port, stream)
}
func (s *server) streamResolutionUsingCorrectResolverFor(host string, port int, stream pb.Destination_GetServer) error {
listener := &endpointListener{stream: stream, podsByIp: s.podsByIp, enableTLS: s.enableTLS}
for _, resolver := range s.resolvers {
resolverCanResolve, err := resolver.canResolve(host, port)
if err != nil {
return fmt.Errorf("resolver [%+v] found error resolving host [%s] port[%d]: %v", resolver, host, port, err)
}
if resolverCanResolve {
return resolver.streamResolution(host, port, listener)
}
}
return fmt.Errorf("cannot find resolver for host [%s] port [%d]", host, port)
}
func buildResolversList(k8sDNSZone string, endpointsWatcher k8s.EndpointsWatcher) ([]streamingDestinationResolver, error) {
var k8sDNSZoneLabels []string
if k8sDNSZone == "" {
k8sDNSZoneLabels = []string{}
} else {
var err error
k8sDNSZoneLabels, err = splitDNSName(k8sDNSZone)
if err != nil {
return nil, err
}
}
k8sResolver := &k8sResolver{
k8sDNSZoneLabels: k8sDNSZoneLabels,
endpointsWatcher: endpointsWatcher,
}
log.Infof("Adding k8s name resolver")
return []streamingDestinationResolver{k8sResolver}, nil
}