package xds import ( "errors" "fmt" "time" envoy_cluster_v3 "github.com/envoyproxy/go-control-plane/envoy/config/cluster/v3" envoy_core_v3 "github.com/envoyproxy/go-control-plane/envoy/config/core/v3" envoy_endpoint_v3 "github.com/envoyproxy/go-control-plane/envoy/config/endpoint/v3" envoy_tls_v3 "github.com/envoyproxy/go-control-plane/envoy/extensions/transport_sockets/tls/v3" envoy_type_v3 "github.com/envoyproxy/go-control-plane/envoy/type/v3" "github.com/golang/protobuf/jsonpb" "github.com/golang/protobuf/proto" "github.com/golang/protobuf/ptypes" "github.com/golang/protobuf/ptypes/any" "github.com/golang/protobuf/ptypes/wrappers" "github.com/hashicorp/consul/agent/connect" "github.com/hashicorp/consul/agent/proxycfg" "github.com/hashicorp/consul/agent/structs" "github.com/hashicorp/consul/logging" ) // clustersFromSnapshot returns the xDS API representation of the "clusters" in the snapshot. func (s *Server) clustersFromSnapshot(_ connectionInfo, cfgSnap *proxycfg.ConfigSnapshot) ([]proto.Message, error) { if cfgSnap == nil { return nil, errors.New("nil config given") } switch cfgSnap.Kind { case structs.ServiceKindConnectProxy: return s.clustersFromSnapshotConnectProxy(cfgSnap) case structs.ServiceKindTerminatingGateway: return s.makeGatewayServiceClusters(cfgSnap, cfgSnap.TerminatingGateway.ServiceGroups, cfgSnap.TerminatingGateway.ServiceResolvers) case structs.ServiceKindMeshGateway: return s.clustersFromSnapshotMeshGateway(cfgSnap) case structs.ServiceKindIngressGateway: return s.clustersFromSnapshotIngressGateway(cfgSnap) 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) clustersFromSnapshotConnectProxy(cfgSnap *proxycfg.ConfigSnapshot) ([]proto.Message, error) { // This sizing is a lower bound. clusters := make([]proto.Message, 0, len(cfgSnap.ConnectProxy.DiscoveryChain)+1) // Include the "app" cluster for the public listener appCluster, err := s.makeAppCluster(cfgSnap, LocalAppClusterName, "", cfgSnap.Proxy.LocalServicePort) if err != nil { return nil, err } clusters = append(clusters, appCluster) // In transparent proxy mode there needs to be a passthrough cluster for traffic going to destinations // that aren't in Consul's catalog. if cfgSnap.Proxy.Mode == structs.ProxyModeTransparent && cfgSnap.ConnectProxy.ClusterConfig != nil && !cfgSnap.ConnectProxy.ClusterConfig.TransparentProxy.CatalogDestinationsOnly { clusters = append(clusters, &envoy_cluster_v3.Cluster{ Name: OriginalDestinationClusterName, ClusterDiscoveryType: &envoy_cluster_v3.Cluster_Type{ Type: envoy_cluster_v3.Cluster_ORIGINAL_DST, }, LbPolicy: envoy_cluster_v3.Cluster_CLUSTER_PROVIDED, ConnectTimeout: ptypes.DurationProto(5 * time.Second), }) } for id, chain := range cfgSnap.ConnectProxy.DiscoveryChain { chainEndpoints, ok := cfgSnap.ConnectProxy.WatchedUpstreamEndpoints[id] if !ok { // this should not happen return nil, fmt.Errorf("no endpoint map for upstream %q", id) } upstreamClusters, err := s.makeUpstreamClustersForDiscoveryChain(id, cfgSnap.ConnectProxy.UpstreamConfig[id], chain, chainEndpoints, cfgSnap) if err != nil { return nil, err } for _, cluster := range upstreamClusters { clusters = append(clusters, cluster) } } for _, u := range cfgSnap.Proxy.Upstreams { if u.DestinationType != structs.UpstreamDestTypePreparedQuery { continue } upstreamCluster, err := s.makeUpstreamClusterForPreparedQuery(u, cfgSnap) if err != nil { return nil, err } clusters = append(clusters, upstreamCluster) } cfgSnap.Proxy.Expose.Finalize() paths := cfgSnap.Proxy.Expose.Paths // Add service health checks to the list of paths to create clusters for if needed if cfgSnap.Proxy.Expose.Checks { psid := structs.NewServiceID(cfgSnap.Proxy.DestinationServiceID, &cfgSnap.ProxyID.EnterpriseMeta) for _, check := range s.CheckFetcher.ServiceHTTPBasedChecks(psid) { p, err := parseCheckPath(check) if err != nil { s.Logger.Warn("failed to create cluster for", "check", check.CheckID, "error", err) continue } paths = append(paths, p) } } // Create a new cluster if we need to expose a port that is different from the service port for _, path := range paths { if path.LocalPathPort == cfgSnap.Proxy.LocalServicePort { continue } c, err := s.makeAppCluster(cfgSnap, makeExposeClusterName(path.LocalPathPort), path.Protocol, path.LocalPathPort) if err != nil { s.Logger.Warn("failed to make local cluster", "path", path.Path, "error", err) continue } clusters = append(clusters, c) } return clusters, nil } func makeExposeClusterName(destinationPort int) string { return fmt.Sprintf("exposed_cluster_%d", destinationPort) } // clustersFromSnapshotMeshGateway returns the xDS API representation of the "clusters" // for a mesh gateway. This will include 1 cluster per remote datacenter as well as // 1 cluster for each service subset. func (s *Server) clustersFromSnapshotMeshGateway(cfgSnap *proxycfg.ConfigSnapshot) ([]proto.Message, error) { datacenters := cfgSnap.MeshGateway.Datacenters() // 1 cluster per remote dc + 1 cluster per local service (this is a lower bound - all subset specific clusters will be appended) clusters := make([]proto.Message, 0, len(datacenters)+len(cfgSnap.MeshGateway.ServiceGroups)) // generate the remote dc clusters for _, dc := range datacenters { if dc == cfgSnap.Datacenter { continue // skip local } opts := gatewayClusterOpts{ name: connect.DatacenterSNI(dc, cfgSnap.Roots.TrustDomain), hostnameEndpoints: cfgSnap.MeshGateway.HostnameDatacenters[dc], isRemote: dc != cfgSnap.Datacenter, } cluster := s.makeGatewayCluster(cfgSnap, opts) clusters = append(clusters, cluster) } if cfgSnap.ServiceMeta[structs.MetaWANFederationKey] == "1" && cfgSnap.ServerSNIFn != nil { // Add all of the remote wildcard datacenter mappings for servers. for _, dc := range datacenters { hostnameEndpoints := cfgSnap.MeshGateway.HostnameDatacenters[dc] // If the DC is our current DC then this cluster is for traffic from a remote DC to a local server. // HostnameDatacenters is populated with gateway addresses, so it does not apply here. if dc == cfgSnap.Datacenter { hostnameEndpoints = nil } opts := gatewayClusterOpts{ name: cfgSnap.ServerSNIFn(dc, ""), hostnameEndpoints: hostnameEndpoints, isRemote: dc != cfgSnap.Datacenter, } cluster := s.makeGatewayCluster(cfgSnap, opts) clusters = append(clusters, cluster) } // And for the current datacenter, send all flavors appropriately. for _, srv := range cfgSnap.MeshGateway.ConsulServers { opts := gatewayClusterOpts{ name: cfgSnap.ServerSNIFn(cfgSnap.Datacenter, srv.Node.Node), } cluster := s.makeGatewayCluster(cfgSnap, opts) clusters = append(clusters, cluster) } } // generate the per-service/subset clusters c, err := s.makeGatewayServiceClusters(cfgSnap, cfgSnap.MeshGateway.ServiceGroups, cfgSnap.MeshGateway.ServiceResolvers) if err != nil { return nil, err } clusters = append(clusters, c...) return clusters, nil } func (s *Server) makeGatewayServiceClusters( cfgSnap *proxycfg.ConfigSnapshot, services map[structs.ServiceName]structs.CheckServiceNodes, resolvers map[structs.ServiceName]*structs.ServiceResolverConfigEntry, ) ([]proto.Message, error) { var hostnameEndpoints structs.CheckServiceNodes switch cfgSnap.Kind { case structs.ServiceKindTerminatingGateway, structs.ServiceKindMeshGateway: default: return nil, fmt.Errorf("unsupported gateway kind %q", cfgSnap.Kind) } clusters := make([]proto.Message, 0, len(services)) for svc := range services { clusterName := connect.ServiceSNI(svc.Name, "", svc.NamespaceOrDefault(), cfgSnap.Datacenter, cfgSnap.Roots.TrustDomain) resolver, hasResolver := resolvers[svc] var loadBalancer *structs.LoadBalancer if !hasResolver { // Use a zero value resolver with no timeout and no subsets resolver = &structs.ServiceResolverConfigEntry{} } if resolver.LoadBalancer != nil { loadBalancer = resolver.LoadBalancer } // When making service clusters we only pass endpoints with hostnames if the kind is a terminating gateway // This is because the services a mesh gateway will route to are not external services and are not addressed by a hostname. if cfgSnap.Kind == structs.ServiceKindTerminatingGateway { hostnameEndpoints = cfgSnap.TerminatingGateway.HostnameServices[svc] } opts := gatewayClusterOpts{ name: clusterName, hostnameEndpoints: hostnameEndpoints, connectTimeout: resolver.ConnectTimeout, } cluster := s.makeGatewayCluster(cfgSnap, opts) if err := s.injectGatewayServiceAddons(cfgSnap, cluster, svc, loadBalancer); err != nil { return nil, err } clusters = append(clusters, cluster) // If there is a service-resolver for this service then also setup a cluster for each subset for name, subset := range resolver.Subsets { subsetHostnameEndpoints, err := s.filterSubsetEndpoints(&subset, hostnameEndpoints) if err != nil { return nil, err } opts := gatewayClusterOpts{ name: connect.ServiceSNI(svc.Name, name, svc.NamespaceOrDefault(), cfgSnap.Datacenter, cfgSnap.Roots.TrustDomain), hostnameEndpoints: subsetHostnameEndpoints, onlyPassing: subset.OnlyPassing, connectTimeout: resolver.ConnectTimeout, } cluster := s.makeGatewayCluster(cfgSnap, opts) if err := s.injectGatewayServiceAddons(cfgSnap, cluster, svc, loadBalancer); err != nil { return nil, err } clusters = append(clusters, cluster) } } return clusters, nil } func (s *Server) injectGatewayServiceAddons(cfgSnap *proxycfg.ConfigSnapshot, c *envoy_cluster_v3.Cluster, svc structs.ServiceName, lb *structs.LoadBalancer) error { switch cfgSnap.Kind { case structs.ServiceKindMeshGateway: // We can't apply hash based LB config to mesh gateways because they rely on inspecting HTTP attributes // and mesh gateways do not decrypt traffic if !lb.IsHashBased() { if err := injectLBToCluster(lb, c); err != nil { return fmt.Errorf("failed to apply load balancer configuration to cluster %q: %v", c.Name, err) } } case structs.ServiceKindTerminatingGateway: // Context used for TLS origination to the cluster if mapping, ok := cfgSnap.TerminatingGateway.GatewayServices[svc]; ok && mapping.CAFile != "" { tlsContext := &envoy_tls_v3.UpstreamTlsContext{ CommonTlsContext: makeCommonTLSContextFromFiles(mapping.CAFile, mapping.CertFile, mapping.KeyFile), } if mapping.SNI != "" { tlsContext.Sni = mapping.SNI } transportSocket, err := makeUpstreamTLSTransportSocket(tlsContext) if err != nil { return err } c.TransportSocket = transportSocket } if err := injectLBToCluster(lb, c); err != nil { return fmt.Errorf("failed to apply load balancer configuration to cluster %q: %v", c.Name, err) } } return nil } func (s *Server) clustersFromSnapshotIngressGateway(cfgSnap *proxycfg.ConfigSnapshot) ([]proto.Message, error) { var clusters []proto.Message createdClusters := make(map[string]bool) for _, upstreams := range cfgSnap.IngressGateway.Upstreams { for _, u := range upstreams { id := u.Identifier() // If we've already created a cluster for this upstream, skip it. Multiple listeners may // reference the same upstream, so we don't need to create duplicate clusters in that case. if createdClusters[id] { continue } chain, ok := cfgSnap.IngressGateway.DiscoveryChain[id] if !ok { // this should not happen return nil, fmt.Errorf("no discovery chain for upstream %q", id) } chainEndpoints, ok := cfgSnap.IngressGateway.WatchedUpstreamEndpoints[id] if !ok { // this should not happen return nil, fmt.Errorf("no endpoint map for upstream %q", id) } upstreamClusters, err := s.makeUpstreamClustersForDiscoveryChain(id, &u, chain, chainEndpoints, cfgSnap) if err != nil { return nil, err } for _, c := range upstreamClusters { clusters = append(clusters, c) } createdClusters[id] = true } } return clusters, nil } func (s *Server) makeAppCluster(cfgSnap *proxycfg.ConfigSnapshot, name, pathProtocol string, port int) (*envoy_cluster_v3.Cluster, error) { var c *envoy_cluster_v3.Cluster var err error cfg, err := ParseProxyConfig(cfgSnap.Proxy.Config) if err != nil { // Don't hard fail on a config typo, just warn. The parse func returns // default config if there is an error so it's safe to continue. s.Logger.Warn("failed to parse Connect.Proxy.Config", "error", err) } // If we have overridden local cluster config try to parse it into an Envoy cluster if cfg.LocalClusterJSON != "" { return makeClusterFromUserConfig(cfg.LocalClusterJSON) } addr := cfgSnap.Proxy.LocalServiceAddress if addr == "" { addr = "127.0.0.1" } c = &envoy_cluster_v3.Cluster{ Name: name, ConnectTimeout: ptypes.DurationProto(time.Duration(cfg.LocalConnectTimeoutMs) * time.Millisecond), ClusterDiscoveryType: &envoy_cluster_v3.Cluster_Type{Type: envoy_cluster_v3.Cluster_STATIC}, LoadAssignment: &envoy_endpoint_v3.ClusterLoadAssignment{ ClusterName: name, Endpoints: []*envoy_endpoint_v3.LocalityLbEndpoints{ { LbEndpoints: []*envoy_endpoint_v3.LbEndpoint{ makeEndpoint(addr, port), }, }, }, }, } protocol := pathProtocol if protocol == "" { protocol = cfg.Protocol } if protocol == "http2" || protocol == "grpc" { c.Http2ProtocolOptions = &envoy_core_v3.Http2ProtocolOptions{} } return c, err } func (s *Server) makeUpstreamClusterForPreparedQuery(upstream structs.Upstream, cfgSnap *proxycfg.ConfigSnapshot) (*envoy_cluster_v3.Cluster, error) { var c *envoy_cluster_v3.Cluster var err error dc := upstream.Datacenter if dc == "" { dc = cfgSnap.Datacenter } sni := connect.UpstreamSNI(&upstream, "", dc, cfgSnap.Roots.TrustDomain) cfg, err := structs.ParseUpstreamConfig(upstream.Config) if err != nil { // Don't hard fail on a config typo, just warn. The parse func returns // default config if there is an error so it's safe to continue. s.Logger.Warn("failed to parse", "upstream", upstream.Identifier(), "error", err) } if cfg.EnvoyClusterJSON != "" { c, err = makeClusterFromUserConfig(cfg.EnvoyClusterJSON) if err != nil { return c, err } // In the happy path don't return yet as we need to inject TLS config still. } if c == nil { c = &envoy_cluster_v3.Cluster{ Name: sni, ConnectTimeout: ptypes.DurationProto(time.Duration(cfg.ConnectTimeoutMs) * time.Millisecond), ClusterDiscoveryType: &envoy_cluster_v3.Cluster_Type{Type: envoy_cluster_v3.Cluster_EDS}, EdsClusterConfig: &envoy_cluster_v3.Cluster_EdsClusterConfig{ EdsConfig: &envoy_core_v3.ConfigSource{ ResourceApiVersion: envoy_core_v3.ApiVersion_V3, ConfigSourceSpecifier: &envoy_core_v3.ConfigSource_Ads{ Ads: &envoy_core_v3.AggregatedConfigSource{}, }, }, }, CircuitBreakers: &envoy_cluster_v3.CircuitBreakers{ Thresholds: makeThresholdsIfNeeded(cfg.Limits), }, OutlierDetection: ToOutlierDetection(cfg.PassiveHealthCheck), } if cfg.Protocol == "http2" || cfg.Protocol == "grpc" { c.Http2ProtocolOptions = &envoy_core_v3.Http2ProtocolOptions{} } } // Enable TLS upstream with the configured client certificate. tlsContext := &envoy_tls_v3.UpstreamTlsContext{ CommonTlsContext: makeCommonTLSContextFromLeaf(cfgSnap, cfgSnap.Leaf()), Sni: sni, } transportSocket, err := makeUpstreamTLSTransportSocket(tlsContext) if err != nil { return nil, err } c.TransportSocket = transportSocket return c, nil } func (s *Server) makeUpstreamClustersForDiscoveryChain( id string, upstream *structs.Upstream, chain *structs.CompiledDiscoveryChain, chainEndpoints map[string]structs.CheckServiceNodes, cfgSnap *proxycfg.ConfigSnapshot, ) ([]*envoy_cluster_v3.Cluster, error) { if chain == nil { return nil, fmt.Errorf("cannot create upstream cluster without discovery chain for %s", id) } configMap := make(map[string]interface{}) if upstream != nil { configMap = upstream.Config } cfg, err := structs.ParseUpstreamConfigNoDefaults(configMap) if err != nil { // Don't hard fail on a config typo, just warn. The parse func returns // default config if there is an error so it's safe to continue. s.Logger.Warn("failed to parse", "upstream", upstream.Identifier(), "error", err) } var escapeHatchCluster *envoy_cluster_v3.Cluster if cfg.EnvoyClusterJSON != "" { if chain.IsDefault() { // If you haven't done anything to setup the discovery chain, then // you can use the envoy_cluster_json escape hatch. escapeHatchCluster, err = makeClusterFromUserConfig(cfg.EnvoyClusterJSON) if err != nil { return nil, err } } else { s.Logger.Warn("ignoring escape hatch setting, because a discovery chain is configured for", "discovery chain", chain.ServiceName, "upstream", upstream.Identifier(), "envoy_cluster_json", chain.ServiceName) } } var out []*envoy_cluster_v3.Cluster for _, node := range chain.Nodes { if node.Type != structs.DiscoveryGraphNodeTypeResolver { continue } failover := node.Resolver.Failover targetID := node.Resolver.Target target := chain.Targets[targetID] // Determine if we have to generate the entire cluster differently. failoverThroughMeshGateway := chain.WillFailoverThroughMeshGateway(node) sni := target.SNI clusterName := CustomizeClusterName(target.Name, chain) if failoverThroughMeshGateway { actualTargetID := firstHealthyTarget( chain.Targets, chainEndpoints, targetID, failover.Targets, ) if actualTargetID != targetID { actualTarget := chain.Targets[actualTargetID] sni = actualTarget.SNI } } s.Logger.Debug("generating cluster for", "cluster", clusterName) c := &envoy_cluster_v3.Cluster{ Name: clusterName, AltStatName: clusterName, ConnectTimeout: ptypes.DurationProto(node.Resolver.ConnectTimeout), ClusterDiscoveryType: &envoy_cluster_v3.Cluster_Type{Type: envoy_cluster_v3.Cluster_EDS}, CommonLbConfig: &envoy_cluster_v3.Cluster_CommonLbConfig{ HealthyPanicThreshold: &envoy_type_v3.Percent{ Value: 0, // disable panic threshold }, }, EdsClusterConfig: &envoy_cluster_v3.Cluster_EdsClusterConfig{ EdsConfig: &envoy_core_v3.ConfigSource{ ResourceApiVersion: envoy_core_v3.ApiVersion_V3, ConfigSourceSpecifier: &envoy_core_v3.ConfigSource_Ads{ Ads: &envoy_core_v3.AggregatedConfigSource{}, }, }, }, CircuitBreakers: &envoy_cluster_v3.CircuitBreakers{ Thresholds: makeThresholdsIfNeeded(cfg.Limits), }, OutlierDetection: ToOutlierDetection(cfg.PassiveHealthCheck), } var lb *structs.LoadBalancer if node.LoadBalancer != nil { lb = node.LoadBalancer } if err := injectLBToCluster(lb, c); err != nil { return nil, fmt.Errorf("failed to apply load balancer configuration to cluster %q: %v", clusterName, err) } proto := cfg.Protocol if proto == "" { proto = chain.Protocol } if proto == "" { proto = "tcp" } if proto == "http2" || proto == "grpc" { c.Http2ProtocolOptions = &envoy_core_v3.Http2ProtocolOptions{} } // Enable TLS upstream with the configured client certificate. tlsContext := &envoy_tls_v3.UpstreamTlsContext{ CommonTlsContext: makeCommonTLSContextFromLeaf(cfgSnap, cfgSnap.Leaf()), Sni: sni, } transportSocket, err := makeUpstreamTLSTransportSocket(tlsContext) if err != nil { return nil, err } c.TransportSocket = transportSocket out = append(out, c) } if escapeHatchCluster != nil { if len(out) != 1 { return nil, fmt.Errorf("cannot inject escape hatch cluster when discovery chain had no nodes") } defaultCluster := out[0] // Overlay what the user provided. escapeHatchCluster.TransportSocket = defaultCluster.TransportSocket out = []*envoy_cluster_v3.Cluster{escapeHatchCluster} } return out, nil } // makeClusterFromUserConfig returns the listener config decoded from an // arbitrary proto3 json format string or an error if it's invalid. // // For now we only support embedding in JSON strings because of the hcl parsing // pain (see Background section in the comment for decode.HookWeakDecodeFromSlice). // This may be fixed in decode.HookWeakDecodeFromSlice in the future. // // When we do that we can support just nesting the config directly into the // JSON/hcl naturally but this is a stop-gap that gets us an escape hatch // immediately. It's also probably not a bad thing to support long-term since // any config generated by other systems will likely be in canonical protobuf // from rather than our slight variant in JSON/hcl. func makeClusterFromUserConfig(configJSON string) (*envoy_cluster_v3.Cluster, error) { // Type field is present so decode it as a types.Any var any any.Any err := jsonpb.UnmarshalString(configJSON, &any) if err != nil { return nil, err } // And then unmarshal the listener again... var c envoy_cluster_v3.Cluster err = proto.Unmarshal(any.Value, &c) if err != nil { return nil, err } return &c, err } type gatewayClusterOpts struct { // name for the cluster name string // isRemote determines whether the cluster is in a remote DC and we should prefer a WAN address isRemote bool // onlyPassing determines whether endpoints that do not have a passing status should be considered unhealthy onlyPassing bool // connectTimeout is the timeout for new network connections to hosts in the cluster connectTimeout time.Duration // hostnameEndpoints is a list of endpoints with a hostname as their address hostnameEndpoints structs.CheckServiceNodes } // makeGatewayCluster creates an Envoy cluster for a mesh or terminating gateway func (s *Server) makeGatewayCluster(snap *proxycfg.ConfigSnapshot, opts gatewayClusterOpts) *envoy_cluster_v3.Cluster { cfg, err := ParseGatewayConfig(snap.Proxy.Config) if err != nil { // Don't hard fail on a config typo, just warn. The parse func returns // default config if there is an error so it's safe to continue. s.Logger.Warn("failed to parse gateway config", "error", err) } if opts.connectTimeout <= 0 { opts.connectTimeout = time.Duration(cfg.ConnectTimeoutMs) * time.Millisecond } cluster := &envoy_cluster_v3.Cluster{ Name: opts.name, ConnectTimeout: ptypes.DurationProto(opts.connectTimeout), // Having an empty config enables outlier detection with default config. OutlierDetection: &envoy_cluster_v3.OutlierDetection{}, } useEDS := true if len(opts.hostnameEndpoints) > 0 { useEDS = false } // If none of the service instances are addressed by a hostname we provide the endpoint IP addresses via EDS if useEDS { cluster.ClusterDiscoveryType = &envoy_cluster_v3.Cluster_Type{Type: envoy_cluster_v3.Cluster_EDS} cluster.EdsClusterConfig = &envoy_cluster_v3.Cluster_EdsClusterConfig{ EdsConfig: &envoy_core_v3.ConfigSource{ ResourceApiVersion: envoy_core_v3.ApiVersion_V3, ConfigSourceSpecifier: &envoy_core_v3.ConfigSource_Ads{ Ads: &envoy_core_v3.AggregatedConfigSource{}, }, }, } return cluster } // When a service instance is addressed by a hostname we have Envoy do the DNS resolution // by setting a DNS cluster type and passing the hostname endpoints via CDS. rate := 10 * time.Second cluster.DnsRefreshRate = ptypes.DurationProto(rate) cluster.DnsLookupFamily = envoy_cluster_v3.Cluster_V4_ONLY discoveryType := envoy_cluster_v3.Cluster_Type{Type: envoy_cluster_v3.Cluster_LOGICAL_DNS} if cfg.DNSDiscoveryType == "strict_dns" { discoveryType.Type = envoy_cluster_v3.Cluster_STRICT_DNS } cluster.ClusterDiscoveryType = &discoveryType endpoints := make([]*envoy_endpoint_v3.LbEndpoint, 0, 1) uniqueHostnames := make(map[string]bool) var ( hostname string idx int fallback *envoy_endpoint_v3.LbEndpoint ) for i, e := range opts.hostnameEndpoints { addr, port := e.BestAddress(opts.isRemote) uniqueHostnames[addr] = true health, weight := calculateEndpointHealthAndWeight(e, opts.onlyPassing) if health == envoy_core_v3.HealthStatus_UNHEALTHY { fallback = makeLbEndpoint(addr, port, health, weight) continue } if len(endpoints) == 0 { endpoints = append(endpoints, makeLbEndpoint(addr, port, health, weight)) hostname = addr idx = i break } } dc := opts.hostnameEndpoints[idx].Node.Datacenter service := opts.hostnameEndpoints[idx].Service.CompoundServiceName() loggerName := logging.TerminatingGateway if snap.Kind == structs.ServiceKindMeshGateway { loggerName = logging.MeshGateway } // Fall back to last unhealthy endpoint if none were healthy if len(endpoints) == 0 { s.Logger.Named(loggerName).Warn("upstream service does not contain any healthy instances", "dc", dc, "service", service.String()) endpoints = append(endpoints, fallback) } if len(uniqueHostnames) > 1 { s.Logger.Named(loggerName). Warn(fmt.Sprintf("service contains instances with more than one unique hostname; only %q be resolved by Envoy", hostname), "dc", dc, "service", service.String()) } cluster.LoadAssignment = &envoy_endpoint_v3.ClusterLoadAssignment{ ClusterName: cluster.Name, Endpoints: []*envoy_endpoint_v3.LocalityLbEndpoints{ { LbEndpoints: endpoints, }, }, } return cluster } func makeThresholdsIfNeeded(limits *structs.UpstreamLimits) []*envoy_cluster_v3.CircuitBreakers_Thresholds { if limits == nil { return nil } threshold := &envoy_cluster_v3.CircuitBreakers_Thresholds{} // Likewise, make sure to not set any threshold values on the zero-value in // order to rely on Envoy defaults if limits.MaxConnections != nil { threshold.MaxConnections = makeUint32Value(*limits.MaxConnections) } if limits.MaxPendingRequests != nil { threshold.MaxPendingRequests = makeUint32Value(*limits.MaxPendingRequests) } if limits.MaxConcurrentRequests != nil { threshold.MaxRequests = makeUint32Value(*limits.MaxConcurrentRequests) } return []*envoy_cluster_v3.CircuitBreakers_Thresholds{threshold} } func makeLbEndpoint(addr string, port int, health envoy_core_v3.HealthStatus, weight int) *envoy_endpoint_v3.LbEndpoint { return &envoy_endpoint_v3.LbEndpoint{ HostIdentifier: &envoy_endpoint_v3.LbEndpoint_Endpoint{ Endpoint: &envoy_endpoint_v3.Endpoint{ Address: &envoy_core_v3.Address{ Address: &envoy_core_v3.Address_SocketAddress{ SocketAddress: &envoy_core_v3.SocketAddress{ Address: addr, PortSpecifier: &envoy_core_v3.SocketAddress_PortValue{ PortValue: uint32(port), }, }, }, }, }, }, HealthStatus: health, LoadBalancingWeight: makeUint32Value(weight), } } func injectLBToCluster(ec *structs.LoadBalancer, c *envoy_cluster_v3.Cluster) error { if ec == nil { return nil } switch ec.Policy { case "": return nil case structs.LBPolicyLeastRequest: c.LbPolicy = envoy_cluster_v3.Cluster_LEAST_REQUEST if ec.LeastRequestConfig != nil { c.LbConfig = &envoy_cluster_v3.Cluster_LeastRequestLbConfig_{ LeastRequestLbConfig: &envoy_cluster_v3.Cluster_LeastRequestLbConfig{ ChoiceCount: &wrappers.UInt32Value{Value: ec.LeastRequestConfig.ChoiceCount}, }, } } case structs.LBPolicyRoundRobin: c.LbPolicy = envoy_cluster_v3.Cluster_ROUND_ROBIN case structs.LBPolicyRandom: c.LbPolicy = envoy_cluster_v3.Cluster_RANDOM case structs.LBPolicyRingHash: c.LbPolicy = envoy_cluster_v3.Cluster_RING_HASH if ec.RingHashConfig != nil { c.LbConfig = &envoy_cluster_v3.Cluster_RingHashLbConfig_{ RingHashLbConfig: &envoy_cluster_v3.Cluster_RingHashLbConfig{ MinimumRingSize: &wrappers.UInt64Value{Value: ec.RingHashConfig.MinimumRingSize}, MaximumRingSize: &wrappers.UInt64Value{Value: ec.RingHashConfig.MaximumRingSize}, }, } } case structs.LBPolicyMaglev: c.LbPolicy = envoy_cluster_v3.Cluster_MAGLEV default: return fmt.Errorf("unsupported load balancer policy %q for cluster %q", ec.Policy, c.Name) } return nil }