open-consul/agent/envoyextensions/extensioncommon/basic_envoy_extender.go

366 lines
11 KiB
Go

package extensioncommon
import (
"fmt"
"strings"
envoy_cluster_v3 "github.com/envoyproxy/go-control-plane/envoy/config/cluster/v3"
envoy_listener_v3 "github.com/envoyproxy/go-control-plane/envoy/config/listener/v3"
envoy_route_v3 "github.com/envoyproxy/go-control-plane/envoy/config/route/v3"
envoy_tcp_proxy_v3 "github.com/envoyproxy/go-control-plane/envoy/extensions/filters/network/tcp_proxy/v3"
envoy_resource_v3 "github.com/envoyproxy/go-control-plane/pkg/resource/v3"
"github.com/hashicorp/go-multierror"
"google.golang.org/protobuf/proto"
"google.golang.org/protobuf/types/known/anypb"
"github.com/hashicorp/consul/agent/xds/xdscommon"
"github.com/hashicorp/consul/api"
)
// BasicExtension is the interface that each user of BasicEnvoyExtender must implement. It
// is responsible for modifying the xDS structures based on only the state of
// the extension.
type BasicExtension interface {
// CanApply determines if the extension can mutate resources for the given xdscommon.ExtensionConfiguration.
CanApply(*RuntimeConfig) bool
// PatchRoute patches a route to include the custom Envoy configuration
// required to integrate with the built in extension template.
PatchRoute(*RuntimeConfig, *envoy_route_v3.RouteConfiguration) (*envoy_route_v3.RouteConfiguration, bool, error)
// PatchCluster patches a cluster to include the custom Envoy configuration
// required to integrate with the built in extension template.
PatchCluster(*RuntimeConfig, *envoy_cluster_v3.Cluster) (*envoy_cluster_v3.Cluster, bool, error)
// PatchFilter patches an Envoy filter to include the custom Envoy
// configuration required to integrate with the built in extension template.
PatchFilter(*RuntimeConfig, *envoy_listener_v3.Filter) (*envoy_listener_v3.Filter, bool, error)
}
var _ EnvoyExtender = (*BasicEnvoyExtender)(nil)
// BasicEnvoyExtender provides convenience functions for iterating and applying modifications
// to Envoy resources.
type BasicEnvoyExtender struct {
Extension BasicExtension
}
func (envoyExtension *BasicEnvoyExtender) Validate(config *RuntimeConfig) error {
return nil
}
func (envoyExtender *BasicEnvoyExtender) Extend(resources *xdscommon.IndexedResources, config *RuntimeConfig) (*xdscommon.IndexedResources, error) {
var resultErr error
switch config.Kind {
case api.ServiceKindTerminatingGateway, api.ServiceKindConnectProxy:
default:
return resources, nil
}
if !envoyExtender.Extension.CanApply(config) {
return resources, nil
}
for _, indexType := range []string{
xdscommon.ListenerType,
xdscommon.RouteType,
xdscommon.ClusterType,
} {
for nameOrSNI, msg := range resources.Index[indexType] {
switch resource := msg.(type) {
case *envoy_cluster_v3.Cluster:
// If the Envoy extension configuration is for an upstream service, the Cluster's
// name must match the upstream service's SNI.
if config.IsUpstream() && !config.MatchesUpstreamServiceSNI(nameOrSNI) {
continue
}
// If the extension's config is for an an inbound listener, the Cluster's name
// must be xdscommon.LocalAppClusterName.
if !config.IsUpstream() && nameOrSNI == xdscommon.LocalAppClusterName {
continue
}
newCluster, patched, err := envoyExtender.Extension.PatchCluster(config, resource)
if err != nil {
resultErr = multierror.Append(resultErr, fmt.Errorf("error patching cluster: %w", err))
continue
}
if patched {
resources.Index[xdscommon.ClusterType][nameOrSNI] = newCluster
}
case *envoy_listener_v3.Listener:
newListener, patched, err := envoyExtender.patchListener(config, resource)
if err != nil {
resultErr = multierror.Append(resultErr, fmt.Errorf("error patching listener: %w", err))
continue
}
if patched {
resources.Index[xdscommon.ListenerType][nameOrSNI] = newListener
}
case *envoy_route_v3.RouteConfiguration:
// If the Envoy extension configuration is for an upstream service, the route's
// name must match the upstream service's Envoy ID.
matchesEnvoyID := config.EnvoyID() == nameOrSNI
if config.IsUpstream() && !config.MatchesUpstreamServiceSNI(nameOrSNI) && !matchesEnvoyID {
continue
}
// There aren't routes for inbound services.
if !config.IsUpstream() {
continue
}
newRoute, patched, err := envoyExtender.Extension.PatchRoute(config, resource)
if err != nil {
resultErr = multierror.Append(resultErr, fmt.Errorf("error patching route: %w", err))
continue
}
if patched {
resources.Index[xdscommon.RouteType][nameOrSNI] = newRoute
}
default:
resultErr = multierror.Append(resultErr, fmt.Errorf("unsupported type was skipped: %T", resource))
}
}
}
return resources, resultErr
}
func (envoyExtension BasicEnvoyExtender) patchListener(config *RuntimeConfig, l *envoy_listener_v3.Listener) (proto.Message, bool, error) {
switch config.Kind {
case api.ServiceKindTerminatingGateway:
return envoyExtension.patchTerminatingGatewayListener(config, l)
case api.ServiceKindConnectProxy:
return envoyExtension.patchConnectProxyListener(config, l)
}
return l, false, nil
}
func (b BasicEnvoyExtender) patchTerminatingGatewayListener(config *RuntimeConfig, l *envoy_listener_v3.Listener) (proto.Message, bool, error) {
// We don't support directly targeting terminating gateways with extensions.
if !config.IsUpstream() {
return l, false, nil
}
var resultErr error
patched := false
for _, filterChain := range l.FilterChains {
sni := getSNI(filterChain)
if sni == "" {
continue
}
// The filter chain's SNI must match the upstream service's SNI.
if !config.MatchesUpstreamServiceSNI(sni) {
continue
}
var filters []*envoy_listener_v3.Filter
for _, filter := range filterChain.Filters {
newFilter, ok, err := b.Extension.PatchFilter(config, filter)
if err != nil {
resultErr = multierror.Append(resultErr, fmt.Errorf("error patching listener filter: %w", err))
filters = append(filters, filter)
continue
}
if ok {
filters = append(filters, newFilter)
patched = true
} else {
filters = append(filters, filter)
}
}
filterChain.Filters = filters
}
return l, patched, resultErr
}
func (b BasicEnvoyExtender) patchConnectProxyListener(config *RuntimeConfig, l *envoy_listener_v3.Listener) (proto.Message, bool, error) {
var resultErr error
envoyID := ""
if i := strings.IndexByte(l.Name, ':'); i != -1 {
envoyID = l.Name[:i]
}
if config.IsUpstream() && envoyID == xdscommon.OutboundListenerName {
return b.patchTProxyListener(config, l)
}
// If the Envoy extension configuration is for an upstream service, the listener's
// name must match the upstream service's EnvoyID or be the outbound listener.
if config.IsUpstream() && envoyID != config.EnvoyID() {
return l, false, nil
}
// If the Envoy extension configuration is for inbound resources, the
// listener must be named xdscommon.PublicListenerName.
if !config.IsUpstream() && envoyID != xdscommon.PublicListenerName {
return l, false, nil
}
var patched bool
for _, filterChain := range l.FilterChains {
var filters []*envoy_listener_v3.Filter
for _, filter := range filterChain.Filters {
newFilter, ok, err := b.Extension.PatchFilter(config, filter)
if err != nil {
resultErr = multierror.Append(resultErr, fmt.Errorf("error patching listener filter: %w", err))
filters = append(filters, filter)
continue
}
if ok {
filters = append(filters, newFilter)
patched = true
} else {
filters = append(filters, filter)
}
}
filterChain.Filters = filters
}
return l, patched, resultErr
}
func (b BasicEnvoyExtender) patchTProxyListener(config *RuntimeConfig, l *envoy_listener_v3.Listener) (proto.Message, bool, error) {
var resultErr error
patched := false
vip := config.Upstreams[config.ServiceName].VIP
for _, filterChain := range l.FilterChains {
var filters []*envoy_listener_v3.Filter
match := filterChainTProxyMatch(vip, filterChain)
if !match {
continue
}
for _, filter := range filterChain.Filters {
newFilter, ok, err := b.Extension.PatchFilter(config, filter)
if err != nil {
resultErr = multierror.Append(resultErr, fmt.Errorf("error patching listener filter: %w", err))
filters = append(filters, filter)
continue
}
if ok {
filters = append(filters, newFilter)
patched = true
} else {
filters = append(filters, filter)
}
}
filterChain.Filters = filters
}
return l, patched, resultErr
}
func filterChainTProxyMatch(vip string, filterChain *envoy_listener_v3.FilterChain) bool {
for _, prefixRange := range filterChain.FilterChainMatch.PrefixRanges {
// Since we always set the address prefix as the full VIP (rather than a prefix), we can just check if they are
// equal to find the matching filter chain.
if vip == prefixRange.AddressPrefix {
return true
}
}
return false
}
func FilterClusterNames(filter *envoy_listener_v3.Filter) map[string]struct{} {
clusterNames := make(map[string]struct{})
if filter == nil {
return clusterNames
}
if config := envoy_resource_v3.GetHTTPConnectionManager(filter); config != nil {
// If it's using RDS, the cluster names will be in the route, rather than in the http filter's route config, so
// we don't return any cluster names in this case. They can be gathered from the route.
if config.GetRds() != nil {
return clusterNames
}
cfg := config.GetRouteConfig()
clusterNames = RouteClusterNames(cfg)
}
if config := GetTCPProxy(filter); config != nil {
clusterNames[config.GetCluster()] = struct{}{}
}
return clusterNames
}
func RouteClusterNames(route *envoy_route_v3.RouteConfiguration) map[string]struct{} {
if route == nil {
return nil
}
clusterNames := make(map[string]struct{})
for _, virtualHost := range route.VirtualHosts {
for _, route := range virtualHost.Routes {
r := route.GetRoute()
if r == nil {
continue
}
if c := r.GetCluster(); c != "" {
clusterNames[r.GetCluster()] = struct{}{}
}
if wc := r.GetWeightedClusters(); wc != nil {
for _, c := range wc.GetClusters() {
if c.Name != "" {
clusterNames[c.Name] = struct{}{}
}
}
}
}
}
return clusterNames
}
func GetTCPProxy(filter *envoy_listener_v3.Filter) *envoy_tcp_proxy_v3.TcpProxy {
if typedConfig := filter.GetTypedConfig(); typedConfig != nil {
config := &envoy_tcp_proxy_v3.TcpProxy{}
if err := anypb.UnmarshalTo(typedConfig, config, proto.UnmarshalOptions{}); err == nil {
return config
}
}
return nil
}
func getSNI(chain *envoy_listener_v3.FilterChain) string {
var sni string
if chain == nil {
return sni
}
if chain.FilterChainMatch == nil {
return sni
}
if len(chain.FilterChainMatch.ServerNames) == 0 {
return sni
}
return chain.FilterChainMatch.ServerNames[0]
}