open-consul/agent/xds/clusters.go
Freddy 5eace88ce2
Expose HTTP-based paths through Connect proxy (#6446)
Fixes: #5396

This PR adds a proxy configuration stanza called expose. These flags register
listeners in Connect sidecar proxies to allow requests to specific HTTP paths from outside of the node. This allows services to protect themselves by only
listening on the loopback interface, while still accepting traffic from non
Connect-enabled services.

Under expose there is a boolean checks flag that would automatically expose all
registered HTTP and gRPC check paths.

This stanza also accepts a paths list to expose individual paths. The primary
use case for this functionality would be to expose paths for third parties like
Prometheus or the kubelet.

Listeners for requests to exposed paths are be configured dynamically at run
time. Any time a proxy, or check can be registered, a listener can also be
created.

In this initial implementation requests to these paths are not
authenticated/encrypted.
2019-09-25 20:55:52 -06:00

452 lines
15 KiB
Go

package xds
import (
"encoding/json"
"errors"
"fmt"
"time"
envoy "github.com/envoyproxy/go-control-plane/envoy/api/v2"
envoyauth "github.com/envoyproxy/go-control-plane/envoy/api/v2/auth"
envoycluster "github.com/envoyproxy/go-control-plane/envoy/api/v2/cluster"
envoycore "github.com/envoyproxy/go-control-plane/envoy/api/v2/core"
envoyendpoint "github.com/envoyproxy/go-control-plane/envoy/api/v2/endpoint"
envoytype "github.com/envoyproxy/go-control-plane/envoy/type"
"github.com/gogo/protobuf/jsonpb"
"github.com/gogo/protobuf/proto"
"github.com/gogo/protobuf/types"
"github.com/hashicorp/consul/agent/connect"
"github.com/hashicorp/consul/agent/proxycfg"
"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)
case structs.ServiceKindMeshGateway:
return s.clustersFromSnapshotMeshGateway(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) clustersFromSnapshotConnectProxy(cfgSnap *proxycfg.ConfigSnapshot, token string) ([]proto.Message, error) {
// TODO(rb): this sizing is a low bound.
clusters := make([]proto.Message, 0, len(cfgSnap.Proxy.Upstreams)+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)
for _, u := range cfgSnap.Proxy.Upstreams {
id := u.Identifier()
if u.DestinationType == structs.UpstreamDestTypePreparedQuery {
upstreamCluster, err := s.makeUpstreamClusterForPreparedQuery(u, cfgSnap)
if err != nil {
return nil, err
}
clusters = append(clusters, upstreamCluster)
} else {
chain := cfgSnap.ConnectProxy.DiscoveryChain[id]
upstreamClusters, err := s.makeUpstreamClustersForDiscoveryChain(u, chain, cfgSnap)
if err != nil {
return nil, err
}
for _, cluster := range upstreamClusters {
clusters = append(clusters, cluster)
}
}
}
cfgSnap.Proxy.Expose.Finalize(s.Logger)
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 {
for _, check := range s.CheckFetcher.ServiceHTTPBasedChecks(cfgSnap.Proxy.DestinationServiceID) {
p, err := parseCheckPath(check)
if err != nil {
s.Logger.Printf("[WARN] envoy: failed to create cluster for check '%s': %v", check.CheckID, 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.Printf("[WARN] envoy: failed to make local cluster for '%s': %s", path.Path, 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, token string) ([]proto.Message, error) {
// 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(cfgSnap.MeshGateway.GatewayGroups)+len(cfgSnap.MeshGateway.ServiceGroups))
// generate the remote dc clusters
for dc, _ := range cfgSnap.MeshGateway.GatewayGroups {
clusterName := connect.DatacenterSNI(dc, cfgSnap.Roots.TrustDomain)
cluster, err := s.makeMeshGatewayCluster(clusterName, cfgSnap)
if err != nil {
return nil, err
}
clusters = append(clusters, cluster)
}
// generate the per-service clusters
for svc, _ := range cfgSnap.MeshGateway.ServiceGroups {
clusterName := connect.ServiceSNI(svc, "", "default", cfgSnap.Datacenter, cfgSnap.Roots.TrustDomain)
cluster, err := s.makeMeshGatewayCluster(clusterName, cfgSnap)
if err != nil {
return nil, err
}
clusters = append(clusters, cluster)
}
// generate the service subset clusters
for svc, resolver := range cfgSnap.MeshGateway.ServiceResolvers {
for subsetName, _ := range resolver.Subsets {
clusterName := connect.ServiceSNI(svc, subsetName, "default", cfgSnap.Datacenter, cfgSnap.Roots.TrustDomain)
cluster, err := s.makeMeshGatewayCluster(clusterName, cfgSnap)
if err != nil {
return nil, err
}
clusters = append(clusters, cluster)
}
}
return clusters, nil
}
func (s *Server) makeAppCluster(cfgSnap *proxycfg.ConfigSnapshot, name, pathProtocol string, port int) (*envoy.Cluster, error) {
var c *envoy.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.Printf("[WARN] envoy: failed to parse Connect.Proxy.Config: %s", 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{
Name: name,
ConnectTimeout: time.Duration(cfg.LocalConnectTimeoutMs) * time.Millisecond,
ClusterDiscoveryType: &envoy.Cluster_Type{Type: envoy.Cluster_STATIC},
LoadAssignment: &envoy.ClusterLoadAssignment{
ClusterName: name,
Endpoints: []envoyendpoint.LocalityLbEndpoints{
{
LbEndpoints: []envoyendpoint.LbEndpoint{
makeEndpoint(name,
addr,
port),
},
},
},
},
}
if cfg.Protocol == "http2" || cfg.Protocol == "grpc" || pathProtocol == "http2" {
c.Http2ProtocolOptions = &envoycore.Http2ProtocolOptions{}
}
return c, err
}
func (s *Server) makeUpstreamClusterForPreparedQuery(upstream structs.Upstream, cfgSnap *proxycfg.ConfigSnapshot) (*envoy.Cluster, error) {
var c *envoy.Cluster
var err error
dc := upstream.Datacenter
if dc == "" {
dc = cfgSnap.Datacenter
}
sni := connect.UpstreamSNI(&upstream, "", dc, cfgSnap.Roots.TrustDomain)
cfg, err := 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.Printf("[WARN] envoy: failed to parse Upstream[%s].Config: %s",
upstream.Identifier(), err)
}
if cfg.ClusterJSON != "" {
c, err = makeClusterFromUserConfig(cfg.ClusterJSON)
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{
Name: sni,
ConnectTimeout: time.Duration(cfg.ConnectTimeoutMs) * time.Millisecond,
ClusterDiscoveryType: &envoy.Cluster_Type{Type: envoy.Cluster_EDS},
EdsClusterConfig: &envoy.Cluster_EdsClusterConfig{
EdsConfig: &envoycore.ConfigSource{
ConfigSourceSpecifier: &envoycore.ConfigSource_Ads{
Ads: &envoycore.AggregatedConfigSource{},
},
},
},
// Having an empty config enables outlier detection with default config.
OutlierDetection: &envoycluster.OutlierDetection{},
}
if cfg.Protocol == "http2" || cfg.Protocol == "grpc" {
c.Http2ProtocolOptions = &envoycore.Http2ProtocolOptions{}
}
}
// Enable TLS upstream with the configured client certificate.
c.TlsContext = &envoyauth.UpstreamTlsContext{
CommonTlsContext: makeCommonTLSContext(cfgSnap),
Sni: sni,
}
return c, nil
}
func (s *Server) makeUpstreamClustersForDiscoveryChain(
upstream structs.Upstream,
chain *structs.CompiledDiscoveryChain,
cfgSnap *proxycfg.ConfigSnapshot,
) ([]*envoy.Cluster, error) {
if chain == nil {
return nil, fmt.Errorf("cannot create upstream cluster without discovery chain")
}
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.Printf("[WARN] envoy: failed to parse Upstream[%s].Config: %s",
upstream.Identifier(), 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 nil, err
}
} else {
s.Logger.Printf("[WARN] envoy: ignoring escape hatch setting Upstream[%s].Config[%s] because a discovery chain for %q is configured",
upstream.Identifier(), "envoy_cluster_json", chain.ServiceName)
}
}
id := upstream.Identifier()
chainEndpointMap, ok := cfgSnap.ConnectProxy.WatchedUpstreamEndpoints[id]
if !ok {
// this should not happen
return nil, fmt.Errorf("no endpoint map for upstream %q", id)
}
var out []*envoy.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,
chainEndpointMap,
targetID,
failover.Targets,
)
if actualTargetID != targetID {
actualTarget := chain.Targets[actualTargetID]
sni = actualTarget.SNI
}
}
s.Logger.Printf("[DEBUG] xds.clusters - generating cluster for %s", clusterName)
c := &envoy.Cluster{
Name: clusterName,
AltStatName: clusterName,
ConnectTimeout: node.Resolver.ConnectTimeout,
ClusterDiscoveryType: &envoy.Cluster_Type{Type: envoy.Cluster_EDS},
CommonLbConfig: &envoy.Cluster_CommonLbConfig{
HealthyPanicThreshold: &envoytype.Percent{
Value: 0, // disable panic threshold
},
},
EdsClusterConfig: &envoy.Cluster_EdsClusterConfig{
EdsConfig: &envoycore.ConfigSource{
ConfigSourceSpecifier: &envoycore.ConfigSource_Ads{
Ads: &envoycore.AggregatedConfigSource{},
},
},
},
// Having an empty config enables outlier detection with default config.
OutlierDetection: &envoycluster.OutlierDetection{},
}
proto := cfg.Protocol
if proto == "" {
proto = chain.Protocol
}
if proto == "" {
proto = "tcp"
}
if proto == "http2" || proto == "grpc" {
c.Http2ProtocolOptions = &envoycore.Http2ProtocolOptions{}
}
// Enable TLS upstream with the configured client certificate.
c.TlsContext = &envoyauth.UpstreamTlsContext{
CommonTlsContext: makeCommonTLSContext(cfgSnap),
Sni: sni,
}
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.TlsContext = defaultCluster.TlsContext
out = []*envoy.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 config.go comment above call to PatchSliceOfMaps). Until we
// refactor config parser a _lot_ user's opaque config that contains arrays will
// be mangled. We could actually fix that up in mapstructure which knows the
// type of the target so could resolve the slices to singletons unambiguously
// and it would work for us here... but we still have the problem that the
// config would render incorrectly in general in our HTTP API responses so we
// really need to fix it "properly".
//
// 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, error) {
var jsonFields map[string]*json.RawMessage
if err := json.Unmarshal([]byte(configJSON), &jsonFields); err != nil {
fmt.Println("Custom error", err, configJSON)
return nil, err
}
var c envoy.Cluster
if _, ok := jsonFields["@type"]; ok {
// Type field is present so decode it as a types.Any
var any types.Any
err := jsonpb.UnmarshalString(configJSON, &any)
if err != nil {
return nil, err
}
// And then unmarshal the listener again...
err = proto.Unmarshal(any.Value, &c)
if err != nil {
return nil, err
}
return &c, err
}
// No @type so try decoding as a straight listener.
err := jsonpb.UnmarshalString(configJSON, &c)
return &c, err
}
func (s *Server) makeMeshGatewayCluster(clusterName string, cfgSnap *proxycfg.ConfigSnapshot) (*envoy.Cluster, error) {
cfg, err := ParseMeshGatewayConfig(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.Printf("[WARN] envoy: failed to parse mesh gateway config: %s", err)
}
return &envoy.Cluster{
Name: clusterName,
ConnectTimeout: time.Duration(cfg.ConnectTimeoutMs) * time.Millisecond,
ClusterDiscoveryType: &envoy.Cluster_Type{Type: envoy.Cluster_EDS},
EdsClusterConfig: &envoy.Cluster_EdsClusterConfig{
EdsConfig: &envoycore.ConfigSource{
ConfigSourceSpecifier: &envoycore.ConfigSource_Ads{
Ads: &envoycore.AggregatedConfigSource{},
},
},
},
// Having an empty config enables outlier detection with default config.
OutlierDetection: &envoycluster.OutlierDetection{},
}, nil
}