Prepare for having different service kinds that are all generic… (#6013)

Default to internal error when service kind is unknown

agent/proxycfg/snapshot.go

@@ -9,6 +9,7 @@ import (
 // It is meant to be point-in-time coherent and is used to deliver the current
 // config state to observers who need it to be pushed in (e.g. XDS server).
 type ConfigSnapshot struct {
+	Kind              structs.ServiceKind
 	ProxyID           string
 	Address           string
 	Port              int
@@ -22,7 +23,12 @@ type ConfigSnapshot struct {
 
 // Valid returns whether or not the snapshot has all required fields filled yet.
 func (s *ConfigSnapshot) Valid() bool {
-	return s.Roots != nil && s.Leaf != nil
+	switch s.Kind {
+	case structs.ServiceKindConnectProxy:
+		return s.Roots != nil && s.Leaf != nil
+	default:
+		return false
+	}
 }
 
 // Clone makes a deep copy of the snapshot we can send to other goroutines

agent/proxycfg/state.go

@@ -38,6 +38,7 @@ type state struct {
 	ctx    context.Context
 	cancel func()
 
+	kind     structs.ServiceKind
 	proxyID  string
 	address  string
 	port     int
@@ -72,6 +73,7 @@ func newState(ns *structs.NodeService, token string) (*state, error) {
 	}
 
 	return &state{
+		kind:     ns.Kind,
 		proxyID:  ns.ID,
 		address:  ns.Address,
 		port:     ns.Port,
@@ -116,9 +118,19 @@ func (s *state) Close() error {
 	return nil
 }
 
-// initWatches sets up the watches needed based on current proxy registration
+// initWatches sets up the watches needed for the particular service
-// state.
 func (s *state) initWatches() error {
+	switch s.kind {
+	case structs.ServiceKindConnectProxy:
+		return s.initWatchesConnectProxy()
+	default:
+		return fmt.Errorf("Unsupported service kind")
+	}
+}
+
+// initWatchesConnectProxy sets up the watches needed based on current proxy registration
+// state.
+func (s *state) initWatchesConnectProxy() error {
 	// Watch for root changes
 	err := s.cache.Notify(s.ctx, cachetype.ConnectCARootName, &structs.DCSpecificRequest{
 		Datacenter:   s.source.Datacenter,
@@ -203,12 +215,18 @@ func (s *state) run() {
 	defer close(s.snapCh)
 
 	snap := ConfigSnapshot{
-		ProxyID:           s.proxyID,
+		Kind:    s.kind,
-		Address:           s.address,
+		ProxyID: s.proxyID,
-		Port:              s.port,
+		Address: s.address,
-		Proxy:             s.proxyCfg,
+		Port:    s.port,
-		UpstreamEndpoints: make(map[string]structs.CheckServiceNodes),
+		Proxy:   s.proxyCfg,
 	}
+
+	switch s.kind {
+	case structs.ServiceKindConnectProxy:
+		snap.UpstreamEndpoints = make(map[string]structs.CheckServiceNodes)
+	}
+
 	// This turns out to be really fiddly/painful by just using time.Timer.C
 	// directly in the code below since you can't detect when a timer is stopped
 	// vs waiting in order to know to reset it. So just use a chan to send
@@ -282,6 +300,15 @@ func (s *state) run() {
 }
 
 func (s *state) handleUpdate(u cache.UpdateEvent, snap *ConfigSnapshot) error {
+	switch s.kind {
+	case structs.ServiceKindConnectProxy:
+		return s.handleUpdateConnectProxy(u, snap)
+	default:
+		return fmt.Errorf("Unsupported service kind")
+	}
+}
+
+func (s *state) handleUpdateConnectProxy(u cache.UpdateEvent, snap *ConfigSnapshot) error {
 	switch u.CorrelationID {
 	case rootsWatchID:
 		roots, ok := u.Result.(*structs.IndexedCARoots)
@@ -340,7 +367,7 @@ func (s *state) Changed(ns *structs.NodeService, token string) bool {
 	if ns == nil {
 		return true
 	}
-	return ns.Kind != structs.ServiceKindConnectProxy ||
+	return ns.Kind != s.kind ||
 		s.proxyID != ns.ID ||
 		s.address != ns.Address ||
 		s.port != ns.Port ||

agent/xds/clusters.go

@@ -19,9 +19,23 @@ import (
 	"github.com/hashicorp/consul/agent/structs"
 )
 
+// clustersFromSnapshot returns the xDS API representation of the "clusters" in the snapshot.
+func (s *Server) clustersFromSnapshot(cfgSnap *proxycfg.ConfigSnapshot, token string) ([]proto.Message, error) {
+	if cfgSnap == nil {
+		return nil, errors.New("nil config given")
+	}
+
+	switch cfgSnap.Kind {
+	case structs.ServiceKindConnectProxy:
+		return s.clustersFromSnapshotConnectProxy(cfgSnap, token)
+	default:
+		return nil, fmt.Errorf("Invalid service kind: %v", cfgSnap.Kind)
+	}
+}
+
 // clustersFromSnapshot returns the xDS API representation of the "clusters"
 // (upstreams) in the snapshot.
-func (s *Server) clustersFromSnapshot(cfgSnap *proxycfg.ConfigSnapshot, token string) ([]proto.Message, error) {
+func (s *Server) clustersFromSnapshotConnectProxy(cfgSnap *proxycfg.ConfigSnapshot, token string) ([]proto.Message, error) {
 	if cfgSnap == nil {
 		return nil, errors.New("nil config given")
 	}

agent/xds/endpoints.go

@@ -2,6 +2,7 @@ package xds
 
 import (
 	"errors"
+	"fmt"
 
 	envoy "github.com/envoyproxy/go-control-plane/envoy/api/v2"
 	envoycore "github.com/envoyproxy/go-control-plane/envoy/api/v2/core"
@@ -14,11 +15,25 @@ import (
 )
 
 // endpointsFromSnapshot returns the xDS API representation of the "endpoints"
-// (upstream instances) in the snapshot.
 func endpointsFromSnapshot(cfgSnap *proxycfg.ConfigSnapshot, token string) ([]proto.Message, error) {
 	if cfgSnap == nil {
 		return nil, errors.New("nil config given")
 	}
+
+	switch cfgSnap.Kind {
+	case structs.ServiceKindConnectProxy:
+		return endpointsFromSnapshotConnectProxy(cfgSnap, token)
+	default:
+		return nil, fmt.Errorf("Invalid service kind: %v", cfgSnap.Kind)
+	}
+}
+
+// endpointsFromSnapshotConnectProxy returns the xDS API representation of the "endpoints"
+// (upstream instances) in the snapshot.
+func endpointsFromSnapshotConnectProxy(cfgSnap *proxycfg.ConfigSnapshot, token string) ([]proto.Message, error) {
+	if cfgSnap == nil {
+		return nil, errors.New("nil config given")
+	}
 	resources := make([]proto.Message, 0, len(cfgSnap.UpstreamEndpoints))
 	for id, endpoints := range cfgSnap.UpstreamEndpoints {
 		la := makeLoadAssignment(id, endpoints)

agent/xds/listeners.go

@@ -24,13 +24,27 @@ import (
 	"github.com/hashicorp/consul/agent/structs"
 )
 
-// listenersFromSnapshot returns the xDS API representation of the "listeners"
+// listenersFromSnapshot returns the xDS API representation of the "listeners" in the snapshot.
-// in the snapshot.
 func (s *Server) listenersFromSnapshot(cfgSnap *proxycfg.ConfigSnapshot, token string) ([]proto.Message, error) {
 	if cfgSnap == nil {
 		return nil, errors.New("nil config given")
 	}
 
+	switch cfgSnap.Kind {
+	case structs.ServiceKindConnectProxy:
+		return s.listenersFromSnapshotConnectProxy(cfgSnap, token)
+	default:
+		return nil, fmt.Errorf("Invalid service kind: %v", cfgSnap.Kind)
+	}
+}
+
+// listenersFromSnapshotConnectProxy returns the xDS API representation of the "listeners"
+// in the snapshot.
+func (s *Server) listenersFromSnapshotConnectProxy(cfgSnap *proxycfg.ConfigSnapshot, token string) ([]proto.Message, error) {
+	if cfgSnap == nil {
+		return nil, errors.New("nil config given")
+	}
+
 	// One listener for each upstream plus the public one
 	resources := make([]proto.Message, len(cfgSnap.Proxy.Upstreams)+1)
 

agent/xds/server.go

@@ -235,8 +235,13 @@ func (s *Server) process(stream ADSStream, reqCh <-chan *envoy.DiscoveryRequest)
 			return err
 		}
 
-		if rule != nil && !rule.ServiceWrite(cfgSnap.Proxy.DestinationServiceName, nil) {
+		switch cfgSnap.Kind {
-			return status.Errorf(codes.PermissionDenied, "permission denied")
+		case structs.ServiceKindConnectProxy:
+			if rule != nil && !rule.ServiceWrite(cfgSnap.Proxy.DestinationServiceName, nil) {
+				return status.Errorf(codes.PermissionDenied, "permission denied")
+			}
+		default:
+			return status.Errorf(codes.Internal, "Invalid service kind")
 		}
 
 		// Authed OK!