consul/agent/xds/endpoints.go

554 lines
17 KiB
Go

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"
envoyendpoint "github.com/envoyproxy/go-control-plane/envoy/api/v2/endpoint"
"github.com/golang/protobuf/proto"
"github.com/hashicorp/consul/agent/connect"
"github.com/hashicorp/consul/agent/proxycfg"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/consul/api"
bexpr "github.com/hashicorp/go-bexpr"
)
const (
UnnamedSubset = ""
)
// endpointsFromSnapshot returns the xDS API representation of the "endpoints"
func (s *Server) endpointsFromSnapshot(cfgSnap *proxycfg.ConfigSnapshot, _ string) ([]proto.Message, error) {
if cfgSnap == nil {
return nil, errors.New("nil config given")
}
switch cfgSnap.Kind {
case structs.ServiceKindConnectProxy:
return s.endpointsFromSnapshotConnectProxy(cfgSnap)
case structs.ServiceKindTerminatingGateway:
return s.endpointsFromSnapshotTerminatingGateway(cfgSnap)
case structs.ServiceKindMeshGateway:
return s.endpointsFromSnapshotMeshGateway(cfgSnap)
case structs.ServiceKindIngressGateway:
return s.endpointsFromSnapshotIngressGateway(cfgSnap)
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 (s *Server) endpointsFromSnapshotConnectProxy(cfgSnap *proxycfg.ConfigSnapshot) ([]proto.Message, error) {
resources := make([]proto.Message, 0,
len(cfgSnap.ConnectProxy.PreparedQueryEndpoints)+len(cfgSnap.ConnectProxy.WatchedUpstreamEndpoints))
for _, u := range cfgSnap.Proxy.Upstreams {
id := u.Identifier()
var chain *structs.CompiledDiscoveryChain
if u.DestinationType != structs.UpstreamDestTypePreparedQuery {
chain = cfgSnap.ConnectProxy.DiscoveryChain[id]
}
if chain == nil {
// We ONLY want this branch for prepared queries.
dc := u.Datacenter
if dc == "" {
dc = cfgSnap.Datacenter
}
clusterName := connect.UpstreamSNI(&u, "", dc, cfgSnap.Roots.TrustDomain)
endpoints, ok := cfgSnap.ConnectProxy.PreparedQueryEndpoints[id]
if ok {
la := makeLoadAssignment(
clusterName,
[]loadAssignmentEndpointGroup{
{Endpoints: endpoints},
},
cfgSnap.Datacenter,
)
resources = append(resources, la)
}
} else {
// Newfangled discovery chain plumbing.
es := s.endpointsFromDiscoveryChain(
u,
chain,
cfgSnap.Datacenter,
cfgSnap.ConnectProxy.WatchedUpstreamEndpoints[id],
cfgSnap.ConnectProxy.WatchedGatewayEndpoints[id],
)
resources = append(resources, es...)
}
}
return resources, nil
}
func (s *Server) filterSubsetEndpoints(subset *structs.ServiceResolverSubset, endpoints structs.CheckServiceNodes) (structs.CheckServiceNodes, error) {
// locally execute the subsets filter
if subset.Filter != "" {
filter, err := bexpr.CreateFilter(subset.Filter, nil, endpoints)
if err != nil {
return nil, err
}
raw, err := filter.Execute(endpoints)
if err != nil {
return nil, err
}
return raw.(structs.CheckServiceNodes), nil
}
return endpoints, nil
}
func (s *Server) endpointsFromSnapshotTerminatingGateway(cfgSnap *proxycfg.ConfigSnapshot) ([]proto.Message, error) {
return s.endpointsFromServicesAndResolvers(cfgSnap, cfgSnap.TerminatingGateway.ServiceGroups, cfgSnap.TerminatingGateway.ServiceResolvers)
}
func (s *Server) endpointsFromSnapshotMeshGateway(cfgSnap *proxycfg.ConfigSnapshot) ([]proto.Message, error) {
datacenters := cfgSnap.MeshGateway.Datacenters()
resources := make([]proto.Message, 0, len(datacenters)+len(cfgSnap.MeshGateway.ServiceGroups))
// generate the endpoints for the gateways in the remote datacenters
for _, dc := range datacenters {
// Skip creating endpoints for mesh gateways in local DC and gateways in remote DCs with a hostname as their address
// EDS cannot resolve hostnames so we provide them through CDS instead
if dc == cfgSnap.Datacenter || len(cfgSnap.MeshGateway.HostnameDatacenters[dc]) > 0 {
continue
}
endpoints, ok := cfgSnap.MeshGateway.GatewayGroups[dc]
if !ok {
endpoints, ok = cfgSnap.MeshGateway.FedStateGateways[dc]
if !ok { // not possible
s.Logger.Error("skipping mesh gateway endpoints because no definition found", "datacenter", dc)
continue
}
}
{ // standard connect
clusterName := connect.DatacenterSNI(dc, cfgSnap.Roots.TrustDomain)
la := makeLoadAssignment(
clusterName,
[]loadAssignmentEndpointGroup{
{Endpoints: endpoints},
},
cfgSnap.Datacenter,
)
resources = append(resources, la)
}
if cfgSnap.ServiceMeta[structs.MetaWANFederationKey] == "1" && cfgSnap.ServerSNIFn != nil {
clusterName := cfgSnap.ServerSNIFn(dc, "")
la := makeLoadAssignment(
clusterName,
[]loadAssignmentEndpointGroup{
{Endpoints: endpoints},
},
cfgSnap.Datacenter,
)
resources = append(resources, la)
}
}
// generate endpoints for our servers if WAN federation is enabled
if cfgSnap.ServiceMeta[structs.MetaWANFederationKey] == "1" && cfgSnap.ServerSNIFn != nil {
var allServersLbEndpoints []*envoyendpoint.LbEndpoint
for _, srv := range cfgSnap.MeshGateway.ConsulServers {
clusterName := cfgSnap.ServerSNIFn(cfgSnap.Datacenter, srv.Node.Node)
addr, port := srv.BestAddress(false /*wan*/)
lbEndpoint := &envoyendpoint.LbEndpoint{
HostIdentifier: &envoyendpoint.LbEndpoint_Endpoint{
Endpoint: &envoyendpoint.Endpoint{
Address: makeAddress(addr, port),
},
},
HealthStatus: envoycore.HealthStatus_UNKNOWN,
}
cla := &envoy.ClusterLoadAssignment{
ClusterName: clusterName,
Endpoints: []*envoyendpoint.LocalityLbEndpoints{{
LbEndpoints: []*envoyendpoint.LbEndpoint{lbEndpoint},
}},
}
allServersLbEndpoints = append(allServersLbEndpoints, lbEndpoint)
resources = append(resources, cla)
}
// And add one catch all so that remote datacenters can dial ANY server
// in this datacenter without knowing its name.
resources = append(resources, &envoy.ClusterLoadAssignment{
ClusterName: cfgSnap.ServerSNIFn(cfgSnap.Datacenter, ""),
Endpoints: []*envoyendpoint.LocalityLbEndpoints{{
LbEndpoints: allServersLbEndpoints,
}},
})
}
// Generate the endpoints for each service and its subsets
e, err := s.endpointsFromServicesAndResolvers(cfgSnap, cfgSnap.MeshGateway.ServiceGroups, cfgSnap.MeshGateway.ServiceResolvers)
if err != nil {
return nil, err
}
resources = append(resources, e...)
return resources, nil
}
func (s *Server) endpointsFromServicesAndResolvers(
cfgSnap *proxycfg.ConfigSnapshot,
services map[structs.ServiceName]structs.CheckServiceNodes,
resolvers map[structs.ServiceName]*structs.ServiceResolverConfigEntry) ([]proto.Message, error) {
resources := make([]proto.Message, 0, len(services))
// generate the endpoints for the linked service groups
for svc, endpoints := range services {
// Skip creating endpoints for services that have hostnames as addresses
// EDS cannot resolve hostnames so we provide them through CDS instead
if cfgSnap.Kind == structs.ServiceKindTerminatingGateway && len(cfgSnap.TerminatingGateway.HostnameServices[svc]) > 0 {
continue
}
clusterEndpoints := make(map[string][]loadAssignmentEndpointGroup)
clusterEndpoints[UnnamedSubset] = []loadAssignmentEndpointGroup{{Endpoints: endpoints, OnlyPassing: false}}
// Collect all of the loadAssignmentEndpointGroups for the various subsets. We do this before generating
// the endpoints for the default/unnamed subset so that we can take into account the DefaultSubset on the
// service-resolver which may prevent the default/unnamed cluster from creating endpoints for all service
// instances.
if resolver, hasResolver := resolvers[svc]; hasResolver {
for subsetName, subset := range resolver.Subsets {
subsetEndpoints, err := s.filterSubsetEndpoints(&subset, endpoints)
if err != nil {
return nil, err
}
groups := []loadAssignmentEndpointGroup{{Endpoints: subsetEndpoints, OnlyPassing: subset.OnlyPassing}}
clusterEndpoints[subsetName] = groups
// if this subset is the default then override the unnamed subset with this configuration
if subsetName == resolver.DefaultSubset {
clusterEndpoints[UnnamedSubset] = groups
}
}
}
// now generate the load assignment for all subsets
for subsetName, groups := range clusterEndpoints {
clusterName := connect.ServiceSNI(svc.Name, subsetName, svc.NamespaceOrDefault(), cfgSnap.Datacenter, cfgSnap.Roots.TrustDomain)
la := makeLoadAssignment(
clusterName,
groups,
cfgSnap.Datacenter,
)
resources = append(resources, la)
}
}
return resources, nil
}
func (s *Server) endpointsFromSnapshotIngressGateway(cfgSnap *proxycfg.ConfigSnapshot) ([]proto.Message, error) {
var resources []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 endpoints for this upstream, skip it. Multiple listeners may
// reference the same upstream, so we don't need to create duplicate endpoints in that case.
if createdClusters[id] {
continue
}
es := s.endpointsFromDiscoveryChain(
u,
cfgSnap.IngressGateway.DiscoveryChain[id],
cfgSnap.Datacenter,
cfgSnap.IngressGateway.WatchedUpstreamEndpoints[id],
cfgSnap.IngressGateway.WatchedGatewayEndpoints[id],
)
resources = append(resources, es...)
createdClusters[id] = true
}
}
return resources, nil
}
func makeEndpoint(clusterName, host string, port int) *envoyendpoint.LbEndpoint {
return &envoyendpoint.LbEndpoint{
HostIdentifier: &envoyendpoint.LbEndpoint_Endpoint{
Endpoint: &envoyendpoint.Endpoint{
Address: makeAddress(host, port),
},
},
}
}
func (s *Server) endpointsFromDiscoveryChain(
upstream structs.Upstream,
chain *structs.CompiledDiscoveryChain,
datacenter string,
upstreamEndpoints, gatewayEndpoints map[string]structs.CheckServiceNodes,
) []proto.Message {
var resources []proto.Message
if chain == nil {
return resources
}
cfg, err := ParseUpstreamConfigNoDefaults(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)
}
var escapeHatchCluster *envoy.Cluster
if cfg.ClusterJSON != "" {
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.ClusterJSON)
if err != nil {
return resources
}
} else {
s.Logger.Warn("ignoring escape hatch setting, because a discovery chain is configued for",
"discovery chain", chain.ServiceName, "upstream", upstream.Identifier(),
"envoy_cluster_json", chain.ServiceName)
}
}
// Find all resolver nodes.
for _, node := range chain.Nodes {
if node.Type != structs.DiscoveryGraphNodeTypeResolver {
continue
}
failover := node.Resolver.Failover
targetID := node.Resolver.Target
target := chain.Targets[targetID]
clusterName := CustomizeClusterName(target.Name, chain)
if escapeHatchCluster != nil {
clusterName = escapeHatchCluster.Name
}
s.Logger.Debug("generating endpoints for", "cluster", clusterName)
// Determine if we have to generate the entire cluster differently.
failoverThroughMeshGateway := chain.WillFailoverThroughMeshGateway(node)
if failoverThroughMeshGateway {
actualTargetID := firstHealthyTarget(
chain.Targets,
upstreamEndpoints,
targetID,
failover.Targets,
)
if actualTargetID != targetID {
targetID = actualTargetID
}
failover = nil
}
primaryGroup, valid := makeLoadAssignmentEndpointGroup(
chain.Targets,
upstreamEndpoints,
gatewayEndpoints,
targetID,
datacenter,
)
if !valid {
continue // skip the cluster if we're still populating the snapshot
}
var endpointGroups []loadAssignmentEndpointGroup
if failover != nil && len(failover.Targets) > 0 {
endpointGroups = make([]loadAssignmentEndpointGroup, 0, len(failover.Targets)+1)
endpointGroups = append(endpointGroups, primaryGroup)
for _, failTargetID := range failover.Targets {
failoverGroup, valid := makeLoadAssignmentEndpointGroup(
chain.Targets,
upstreamEndpoints,
gatewayEndpoints,
failTargetID,
datacenter,
)
if !valid {
continue // skip the failover target if we're still populating the snapshot
}
endpointGroups = append(endpointGroups, failoverGroup)
}
} else {
endpointGroups = append(endpointGroups, primaryGroup)
}
la := makeLoadAssignment(
clusterName,
endpointGroups,
datacenter,
)
resources = append(resources, la)
}
return resources
}
type loadAssignmentEndpointGroup struct {
Endpoints structs.CheckServiceNodes
OnlyPassing bool
OverrideHealth envoycore.HealthStatus
}
func makeLoadAssignment(clusterName string, endpointGroups []loadAssignmentEndpointGroup, localDatacenter string) *envoy.ClusterLoadAssignment {
cla := &envoy.ClusterLoadAssignment{
ClusterName: clusterName,
Endpoints: make([]*envoyendpoint.LocalityLbEndpoints, 0, len(endpointGroups)),
}
if len(endpointGroups) > 1 {
cla.Policy = &envoy.ClusterLoadAssignment_Policy{
// We choose such a large value here that the failover math should
// in effect not happen until zero instances are healthy.
OverprovisioningFactor: makeUint32Value(100000),
}
}
for priority, endpointGroup := range endpointGroups {
endpoints := endpointGroup.Endpoints
es := make([]*envoyendpoint.LbEndpoint, 0, len(endpoints))
for _, ep := range endpoints {
// TODO (mesh-gateway) - should we respect the translate_wan_addrs configuration here or just always use the wan for cross-dc?
addr, port := ep.BestAddress(localDatacenter != ep.Node.Datacenter)
healthStatus, weight := calculateEndpointHealthAndWeight(ep, endpointGroup.OnlyPassing)
if endpointGroup.OverrideHealth != envoycore.HealthStatus_UNKNOWN {
healthStatus = endpointGroup.OverrideHealth
}
es = append(es, &envoyendpoint.LbEndpoint{
HostIdentifier: &envoyendpoint.LbEndpoint_Endpoint{
Endpoint: &envoyendpoint.Endpoint{
Address: makeAddress(addr, port),
},
},
HealthStatus: healthStatus,
LoadBalancingWeight: makeUint32Value(weight),
})
}
cla.Endpoints = append(cla.Endpoints, &envoyendpoint.LocalityLbEndpoints{
Priority: uint32(priority),
LbEndpoints: es,
})
}
return cla
}
func makeLoadAssignmentEndpointGroup(
targets map[string]*structs.DiscoveryTarget,
targetHealth map[string]structs.CheckServiceNodes,
gatewayHealth map[string]structs.CheckServiceNodes,
targetID string,
currentDatacenter string,
) (loadAssignmentEndpointGroup, bool) {
realEndpoints, ok := targetHealth[targetID]
if !ok {
// skip the cluster if we're still populating the snapshot
return loadAssignmentEndpointGroup{}, false
}
target := targets[targetID]
var gatewayDatacenter string
switch target.MeshGateway.Mode {
case structs.MeshGatewayModeRemote:
gatewayDatacenter = target.Datacenter
case structs.MeshGatewayModeLocal:
gatewayDatacenter = currentDatacenter
}
if gatewayDatacenter == "" {
return loadAssignmentEndpointGroup{
Endpoints: realEndpoints,
OnlyPassing: target.Subset.OnlyPassing,
}, true
}
// If using a mesh gateway we need to pull those endpoints instead.
gatewayEndpoints, ok := gatewayHealth[gatewayDatacenter]
if !ok {
// skip the cluster if we're still populating the snapshot
return loadAssignmentEndpointGroup{}, false
}
// But we will use the health from the actual backend service.
overallHealth := envoycore.HealthStatus_UNHEALTHY
for _, ep := range realEndpoints {
health, _ := calculateEndpointHealthAndWeight(ep, target.Subset.OnlyPassing)
if health == envoycore.HealthStatus_HEALTHY {
overallHealth = envoycore.HealthStatus_HEALTHY
break
}
}
return loadAssignmentEndpointGroup{
Endpoints: gatewayEndpoints,
OverrideHealth: overallHealth,
}, true
}
func calculateEndpointHealthAndWeight(
ep structs.CheckServiceNode,
onlyPassing bool,
) (envoycore.HealthStatus, int) {
healthStatus := envoycore.HealthStatus_HEALTHY
weight := 1
if ep.Service.Weights != nil {
weight = ep.Service.Weights.Passing
}
for _, chk := range ep.Checks {
if chk.Status == api.HealthCritical {
healthStatus = envoycore.HealthStatus_UNHEALTHY
}
if onlyPassing && chk.Status != api.HealthPassing {
healthStatus = envoycore.HealthStatus_UNHEALTHY
}
if chk.Status == api.HealthWarning && ep.Service.Weights != nil {
weight = ep.Service.Weights.Warning
}
}
// Make weights fit Envoy's limits. A zero weight means that either Warning
// (likely) or Passing (weirdly) weight has been set to 0 effectively making
// this instance unhealthy and should not be sent traffic.
if weight < 1 {
healthStatus = envoycore.HealthStatus_UNHEALTHY
weight = 1
}
if weight > 128 {
weight = 128
}
return healthStatus, weight
}