linkerd2/controller/api/destination/server.go

452 lines
13 KiB
Go

package destination
import (
"encoding/json"
"fmt"
"net"
"strconv"
"strings"
pb "github.com/linkerd/linkerd2-proxy-api/go/destination"
"github.com/linkerd/linkerd2/controller/api/destination/watcher"
sp "github.com/linkerd/linkerd2/controller/gen/apis/serviceprofile/v1alpha2"
"github.com/linkerd/linkerd2/controller/k8s"
"github.com/linkerd/linkerd2/pkg/prometheus"
logging "github.com/sirupsen/logrus"
"google.golang.org/grpc"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/peer"
"google.golang.org/grpc/status"
coreinformers "k8s.io/client-go/informers/core/v1"
)
type (
server struct {
endpoints *watcher.EndpointsWatcher
profiles *watcher.ProfileWatcher
trafficSplits *watcher.TrafficSplitWatcher
ips *watcher.IPWatcher
nodes coreinformers.NodeInformer
enableH2Upgrade bool
controllerNS string
identityTrustDomain string
clusterDomain string
k8sAPI *k8s.API
log *logging.Entry
shutdown <-chan struct{}
}
)
// NewServer returns a new instance of the destination server.
//
// The destination server serves service discovery and other 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 string,
controllerNS string,
identityTrustDomain string,
enableH2Upgrade bool,
enableEndpointSlices bool,
k8sAPI *k8s.API,
clusterDomain string,
shutdown <-chan struct{},
) *grpc.Server {
log := logging.WithFields(logging.Fields{
"addr": addr,
"component": "server",
})
endpoints := watcher.NewEndpointsWatcher(k8sAPI, log, enableEndpointSlices)
profiles := watcher.NewProfileWatcher(k8sAPI, log)
trafficSplits := watcher.NewTrafficSplitWatcher(k8sAPI, log)
ips := watcher.NewIPWatcher(k8sAPI, endpoints, log)
srv := server{
endpoints,
profiles,
trafficSplits,
ips,
k8sAPI.Node(),
enableH2Upgrade,
controllerNS,
identityTrustDomain,
clusterDomain,
k8sAPI,
log,
shutdown,
}
s := prometheus.NewGrpcServer()
// linkerd2-proxy-api/destination.Destination (proxy-facing)
pb.RegisterDestinationServer(s, &srv)
return s
}
func (s *server) Get(dest *pb.GetDestination, stream pb.Destination_GetServer) error {
client, _ := peer.FromContext(stream.Context())
log := s.log
if client != nil {
log = s.log.WithField("remote", client.Addr)
}
log.Debugf("Get %s", dest.GetPath())
var token contextToken
if dest.GetContextToken() != "" {
token = s.parseContextToken(dest.GetContextToken())
log.Debugf("Dest token: %v", token)
}
translator := newEndpointTranslator(
s.controllerNS,
s.identityTrustDomain,
s.enableH2Upgrade,
dest.GetPath(),
token.NodeName,
s.nodes,
stream,
log,
)
// The host must be fully-qualified or be an IP address.
host, port, err := getHostAndPort(dest.GetPath())
if err != nil {
log.Debugf("Invalid service %s", dest.GetPath())
return status.Errorf(codes.InvalidArgument, "Invalid authority: %s", dest.GetPath())
}
if ip := net.ParseIP(host); ip != nil {
err := s.ips.Subscribe(host, port, translator)
if err != nil {
log.Errorf("Failed to subscribe to %s: %s", dest.GetPath(), err)
return err
}
defer s.ips.Unsubscribe(host, port, translator)
} else {
service, instanceID, err := parseK8sServiceName(host, s.clusterDomain)
if err != nil {
log.Debugf("Invalid service %s", dest.GetPath())
return status.Errorf(codes.InvalidArgument, "Invalid authority: %s", dest.GetPath())
}
err = s.endpoints.Subscribe(service, port, instanceID, translator)
if err != nil {
if _, ok := err.(watcher.InvalidService); ok {
log.Debugf("Invalid service %s", dest.GetPath())
return status.Errorf(codes.InvalidArgument, "Invalid authority: %s", dest.GetPath())
}
log.Errorf("Failed to subscribe to %s: %s", dest.GetPath(), err)
return err
}
defer s.endpoints.Unsubscribe(service, port, instanceID, translator)
}
select {
case <-s.shutdown:
case <-stream.Context().Done():
log.Debugf("Get %s cancelled", dest.GetPath())
}
return nil
}
func (s *server) GetProfile(dest *pb.GetDestination, stream pb.Destination_GetProfileServer) error {
log := s.log
client, _ := peer.FromContext(stream.Context())
if client != nil {
log = log.WithField("remote", client.Addr)
}
log.Debugf("GetProfile(%+v)", dest)
path := dest.GetPath()
// The host must be fully-qualified or be an IP address.
host, port, err := getHostAndPort(path)
if err != nil {
log.Debugf("Invalid authority %s", path)
return status.Errorf(codes.InvalidArgument, "invalid authority: %s", err)
}
// The stream will subscribe to profile updates for `service`.
var service watcher.ServiceID
// `instanceID` is used when subscribing to endpoints of `service`.
var instanceID string
// If `host` is an IP, `fqn` must be constructed from the namespace and
// name of the service that the IP maps to.
var fqn string
if ip := net.ParseIP(host); ip != nil {
// Get the service that the IP currently maps to.
svcID, err := s.ips.GetSvcID(ip.String())
if err != nil {
return err
}
if svcID != nil {
service = *svcID
fqn = fmt.Sprintf("%s.%s.svc.%s", service.Name, service.Namespace, s.clusterDomain)
} else {
// If the IP does not map to a service, check if it maps to a pod
pod, err := s.ips.GetPod(ip.String())
if err != nil {
return err
}
var endpoint *pb.WeightedAddr
opaquePorts := make(map[uint32]struct{})
if pod != nil {
// If the IP maps to a pod, we create a single endpoint and
// return it in the DestinationProfile response
podSet := s.ips.PodToAddressSet(pod).WithPort(port)
podID := watcher.PodID{
Namespace: pod.Namespace,
Name: pod.Name,
}
if err != nil {
log.Errorf("failed to set opaque port annotation on pod: %s", err)
}
opaquePorts, err = getOpaquePortsAnnotations(pod)
if err != nil {
log.Errorf("failed to get opaque ports annotation for pod: %s", err)
}
endpoint, err = toWeightedAddr(podSet.Addresses[podID], opaquePorts, s.enableH2Upgrade, s.identityTrustDomain, s.controllerNS, log)
if err != nil {
return err
}
// `Get` doesn't include the namespace in the per-endpoint
// metadata, so it needs to be special-cased.
endpoint.MetricLabels["namespace"] = pod.Namespace
}
// When the IP does not map to a service, the default profile is
// sent without subscribing for future updates. If the IP mapped
// to a pod, then the endpoint will be set in the response.
translator := newProfileTranslator(stream, log, "", port, endpoint)
// If there are opaque ports then update the profile translator
// with a service profile that has those values
//
// TODO: Remove endpoint from profileTranslator and set it here
// similar to opaque ports
if len(opaquePorts) != 0 {
sp := sp.ServiceProfile{}
sp.Spec.OpaquePorts = opaquePorts
translator.Update(&sp)
} else {
translator.Update(nil)
}
select {
case <-s.shutdown:
case <-stream.Context().Done():
log.Debugf("GetProfile(%+v) cancelled", dest)
}
return nil
}
} else {
service, instanceID, err = parseK8sServiceName(host, s.clusterDomain)
if err != nil {
log.Debugf("Invalid service %s", path)
return status.Errorf(codes.InvalidArgument, "invalid service: %s", err)
}
fqn = host
}
// We build up the pipeline of profile updaters backwards, starting from
// the translator which takes profile updates, translates them to protobuf
// and pushes them onto the gRPC stream.
translator := newProfileTranslator(stream, log, fqn, port, nil)
// The opaque ports adaptor merges traffic split updates with opaque ports
// updates and publishes the result to the translator
opAdaptor := newOpaquePortsAdaptor(translator, s.k8sAPI, log)
// Subscribe the adaptor to endpoint updates.
// TODO: use a hostname?
err = s.endpoints.Subscribe(service, port, instanceID, opAdaptor)
if err != nil {
log.Warnf("Failed to subscribe to endpoint updates for %s: %s", path, err)
}
defer s.endpoints.Unsubscribe(service, port, instanceID, opAdaptor)
// The traffic split adaptor merges profile updates with traffic split
// updates and publishes the result to the opaque port adaptor.
tsAdaptor := newTrafficSplitAdaptor(opAdaptor, service, port, s.clusterDomain)
// Subscribe the adaptor to traffic split updates.
err = s.trafficSplits.Subscribe(service, tsAdaptor)
if err != nil {
log.Warnf("Failed to subscribe to traffic split for %s: %s", path, err)
return err
}
defer s.trafficSplits.Unsubscribe(service, tsAdaptor)
// The fallback accepts updates from a primary and secondary source and
// passes the appropriate profile updates to the adaptor.
primary, secondary := newFallbackProfileListener(tsAdaptor)
// If we have a context token, we create two subscriptions: one with the
// context token which sends updates to the primary listener and one without
// the context token which sends updates to the secondary listener. It is
// up to the fallbackProfileListener to merge updates from the primary and
// secondary listeners and send the appropriate updates to the stream.
if dest.GetContextToken() != "" {
ctxToken := s.parseContextToken(dest.GetContextToken())
profile, err := profileID(fqn, ctxToken, s.clusterDomain)
if err != nil {
log.Debugf("Invalid service %s", path)
return status.Errorf(codes.InvalidArgument, "invalid profile ID: %s", err)
}
err = s.profiles.Subscribe(profile, primary)
if err != nil {
log.Warnf("Failed to subscribe to profile %s: %s", path, err)
return err
}
defer s.profiles.Unsubscribe(profile, primary)
}
profile, err := profileID(fqn, contextToken{}, s.clusterDomain)
if err != nil {
log.Debugf("Invalid service %s", path)
return status.Errorf(codes.InvalidArgument, "invalid profile ID: %s", err)
}
err = s.profiles.Subscribe(profile, secondary)
if err != nil {
log.Warnf("Failed to subscribe to profile %s: %s", path, err)
return err
}
defer s.profiles.Unsubscribe(profile, secondary)
select {
case <-s.shutdown:
case <-stream.Context().Done():
log.Debugf("GetProfile(%+v) cancelled", dest)
}
return nil
}
////////////
/// util ///
////////////
type contextToken struct {
Ns string `json:"ns,omitempty"`
NodeName string `json:"nodeName,omitempty"`
}
func (s *server) parseContextToken(token string) contextToken {
ctxToken := contextToken{}
if err := json.Unmarshal([]byte(token), &ctxToken); err != nil {
// if json is invalid, means token can have ns:<namespace> form
parts := strings.Split(token, ":")
if len(parts) == 2 && parts[0] == "ns" {
s.log.Warnf("context token %s using old token format", token)
ctxToken = contextToken{
Ns: parts[1],
}
} else {
s.log.Errorf("context token %s is invalid: %s", token, err)
}
}
return ctxToken
}
func profileID(authority string, ctxToken contextToken, clusterDomain string) (watcher.ProfileID, error) {
host, _, err := getHostAndPort(authority)
if err != nil {
return watcher.ProfileID{}, fmt.Errorf("invalid authority: %s", err)
}
service, _, err := parseK8sServiceName(host, clusterDomain)
if err != nil {
return watcher.ProfileID{}, fmt.Errorf("invalid k8s service name: %s", err)
}
id := watcher.ProfileID{
Name: fmt.Sprintf("%s.%s.svc.%s", service.Name, service.Namespace, clusterDomain),
Namespace: service.Namespace,
}
if ctxToken.Ns != "" {
id.Namespace = ctxToken.Ns
}
return id, nil
}
func getHostAndPort(authority string) (string, watcher.Port, error) {
hostPort := strings.Split(authority, ":")
if len(hostPort) > 2 {
return "", 0, fmt.Errorf("Invalid destination %s", authority)
}
host := hostPort[0]
port := 80
if len(hostPort) == 2 {
var err error
port, err = strconv.Atoi(hostPort[1])
if err != nil {
return "", 0, fmt.Errorf("Invalid port %s", hostPort[1])
}
}
return host, watcher.Port(port), nil
}
type instanceID = string
// parseK8sServiceName is a utility that destructures a Kubernetes service hostname into its constituent components.
//
// If the authority does not represent a Kubernetes service, an error is returned.
//
// If the hostname is a pod DNS name, then the pod's name (instanceID) is returned
// as well. See https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/.
func parseK8sServiceName(fqdn, clusterDomain string) (watcher.ServiceID, instanceID, error) {
labels := strings.Split(fqdn, ".")
suffix := append([]string{"svc"}, strings.Split(clusterDomain, ".")...)
if !hasSuffix(labels, suffix) {
return watcher.ServiceID{}, "", fmt.Errorf("name %s does not match cluster domain %s", fqdn, clusterDomain)
}
n := len(labels)
if n == 2+len(suffix) {
// <service>.<namespace>.<suffix>
service := watcher.ServiceID{
Name: labels[0],
Namespace: labels[1],
}
return service, "", nil
}
if n == 3+len(suffix) {
// <instance-id>.<service>.<namespace>.<suffix>
instanceID := labels[0]
service := watcher.ServiceID{
Name: labels[1],
Namespace: labels[2],
}
return service, instanceID, nil
}
return watcher.ServiceID{}, "", fmt.Errorf("invalid k8s service %s", fqdn)
}
func hasSuffix(slice []string, suffix []string) bool {
if len(slice) < len(suffix) {
return false
}
for i, s := range slice[len(slice)-len(suffix):] {
if s != suffix[i] {
return false
}
}
return true
}