open-consul/agent/proxycfg/api_gateway.go
Derek Menteer f661437c8a
Fix nil-pointer panics from proxycfg package. (#16277)
Prior to this PR, servers / agents would panic and crash if an ingress
or api gateway were configured to use a discovery chain that both:

1. Referenced a peered service
2. Had a mesh gateway mode of local

This could occur, because code for handling upstream watches was shared
between both connect-proxy and the gateways. As a short-term fix, this
PR ensures that the maps are always initialized for these gateway services.

This PR also wraps the proxycfg execution and service
registration calls with recover statements to ensure that future issues
like this do not put the server into an unrecoverable state.
2023-02-15 11:54:44 -06:00

464 lines
16 KiB
Go

package proxycfg
import (
"context"
"fmt"
cachetype "github.com/hashicorp/consul/agent/cache-types"
"github.com/hashicorp/consul/agent/proxycfg/internal/watch"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/consul/proto/pbpeering"
)
var _ kindHandler = (*handlerAPIGateway)(nil)
// handlerAPIGateway generates a new ConfigSnapshot in response to
// changes related to an api-gateway.
type handlerAPIGateway struct {
handlerState
}
// initialize sets up the initial watches needed based on the api-gateway registration
func (h *handlerAPIGateway) initialize(ctx context.Context) (ConfigSnapshot, error) {
snap := newConfigSnapshotFromServiceInstance(h.serviceInstance, h.stateConfig)
// Watch for root changes
err := h.dataSources.CARoots.Notify(ctx, &structs.DCSpecificRequest{
Datacenter: h.source.Datacenter,
QueryOptions: structs.QueryOptions{Token: h.token},
Source: *h.source,
}, rootsWatchID, h.ch)
if err != nil {
return snap, err
}
// Get information about the entire service mesh.
err = h.dataSources.ConfigEntry.Notify(ctx, &structs.ConfigEntryQuery{
Kind: structs.MeshConfig,
Name: structs.MeshConfigMesh,
Datacenter: h.source.Datacenter,
QueryOptions: structs.QueryOptions{Token: h.token},
EnterpriseMeta: *structs.DefaultEnterpriseMetaInPartition(h.proxyID.PartitionOrDefault()),
}, meshConfigEntryID, h.ch)
if err != nil {
return snap, err
}
// Watch the api-gateway's config entry
err = h.subscribeToConfigEntry(ctx, structs.APIGateway, h.service, gatewayConfigWatchID)
if err != nil {
return snap, err
}
// Watch the bound-api-gateway's config entry
err = h.subscribeToConfigEntry(ctx, structs.BoundAPIGateway, h.service, gatewayConfigWatchID)
if err != nil {
return snap, err
}
snap.APIGateway.Listeners = make(map[string]structs.APIGatewayListener)
snap.APIGateway.BoundListeners = make(map[string]structs.BoundAPIGatewayListener)
snap.APIGateway.HTTPRoutes = watch.NewMap[structs.ResourceReference, *structs.HTTPRouteConfigEntry]()
snap.APIGateway.TCPRoutes = watch.NewMap[structs.ResourceReference, *structs.TCPRouteConfigEntry]()
snap.APIGateway.Certificates = watch.NewMap[structs.ResourceReference, *structs.InlineCertificateConfigEntry]()
snap.APIGateway.Upstreams = make(listenerRouteUpstreams)
snap.APIGateway.UpstreamsSet = make(routeUpstreamSet)
// These need to be initialized here but are set by handlerUpstreams
snap.APIGateway.DiscoveryChain = make(map[UpstreamID]*structs.CompiledDiscoveryChain)
snap.APIGateway.PeerUpstreamEndpoints = watch.NewMap[UpstreamID, structs.CheckServiceNodes]()
snap.APIGateway.PeerUpstreamEndpointsUseHostnames = make(map[UpstreamID]struct{})
snap.APIGateway.UpstreamPeerTrustBundles = watch.NewMap[string, *pbpeering.PeeringTrustBundle]()
snap.APIGateway.WatchedDiscoveryChains = make(map[UpstreamID]context.CancelFunc)
snap.APIGateway.WatchedGateways = make(map[UpstreamID]map[string]context.CancelFunc)
snap.APIGateway.WatchedGatewayEndpoints = make(map[UpstreamID]map[string]structs.CheckServiceNodes)
snap.APIGateway.WatchedLocalGWEndpoints = watch.NewMap[string, structs.CheckServiceNodes]()
snap.APIGateway.WatchedUpstreams = make(map[UpstreamID]map[string]context.CancelFunc)
snap.APIGateway.WatchedUpstreamEndpoints = make(map[UpstreamID]map[string]structs.CheckServiceNodes)
return snap, nil
}
func (h *handlerAPIGateway) subscribeToConfigEntry(ctx context.Context, kind, name, watchID string) error {
return h.dataSources.ConfigEntry.Notify(ctx, &structs.ConfigEntryQuery{
Kind: kind,
Name: name,
Datacenter: h.source.Datacenter,
QueryOptions: structs.QueryOptions{Token: h.token},
EnterpriseMeta: h.proxyID.EnterpriseMeta,
}, watchID, h.ch)
}
// handleUpdate responds to changes in the api-gateway. In general, we want
// to crawl the various resources related to or attached to the gateway and
// collect the list of things need to generate xDS. This list of resources
// includes the bound-api-gateway, http-routes, tcp-routes, and inline-certificates.
func (h *handlerAPIGateway) handleUpdate(ctx context.Context, u UpdateEvent, snap *ConfigSnapshot) error {
if u.Err != nil {
return fmt.Errorf("error filling agent cache: %v", u.Err)
}
switch {
case u.CorrelationID == rootsWatchID:
// Handle change in the CA roots
if err := h.handleRootCAUpdate(u, snap); err != nil {
return err
}
case u.CorrelationID == gatewayConfigWatchID:
// Handle change in the api-gateway or bound-api-gateway config entry
if err := h.handleGatewayConfigUpdate(ctx, u, snap); err != nil {
return err
}
case u.CorrelationID == inlineCertificateConfigWatchID:
// Handle change in an attached inline-certificate config entry
if err := h.handleInlineCertConfigUpdate(ctx, u, snap); err != nil {
return err
}
case u.CorrelationID == routeConfigWatchID:
// Handle change in an attached http-route or tcp-route config entry
if err := h.handleRouteConfigUpdate(ctx, u, snap); err != nil {
return err
}
default:
return (*handlerUpstreams)(h).handleUpdateUpstreams(ctx, u, snap)
}
return nil
}
// handleRootCAUpdate responds to changes in the watched root CA for a gateway
func (h *handlerAPIGateway) handleRootCAUpdate(u UpdateEvent, snap *ConfigSnapshot) error {
roots, ok := u.Result.(*structs.IndexedCARoots)
if !ok {
return fmt.Errorf("invalid type for response: %T", u.Result)
}
snap.Roots = roots
return nil
}
// handleGatewayConfigUpdate responds to changes in the watched config entry for a gateway.
// In particular, we want to make sure that we're subscribing to any attached resources such
// as routes and certificates. These additional subscriptions will enable us to update the
// config snapshot appropriately for any route or certificate changes.
func (h *handlerAPIGateway) handleGatewayConfigUpdate(ctx context.Context, u UpdateEvent, snap *ConfigSnapshot) error {
resp, ok := u.Result.(*structs.ConfigEntryResponse)
if !ok {
return fmt.Errorf("invalid type for response: %T", u.Result)
} else if resp.Entry == nil {
return nil
}
switch gwConf := resp.Entry.(type) {
case *structs.BoundAPIGatewayConfigEntry:
snap.APIGateway.BoundGatewayConfig = gwConf
seenRefs := make(map[structs.ResourceReference]any)
for _, listener := range gwConf.Listeners {
snap.APIGateway.BoundListeners[listener.Name] = listener
// Subscribe to changes in each attached x-route config entry
for _, ref := range listener.Routes {
seenRefs[ref] = struct{}{}
ctx, cancel := context.WithCancel(ctx)
switch ref.Kind {
case structs.HTTPRoute:
snap.APIGateway.HTTPRoutes.InitWatch(ref, cancel)
case structs.TCPRoute:
snap.APIGateway.TCPRoutes.InitWatch(ref, cancel)
default:
cancel()
return fmt.Errorf("unexpected route kind on gateway: %s", ref.Kind)
}
err := h.subscribeToConfigEntry(ctx, ref.Kind, ref.Name, routeConfigWatchID)
if err != nil {
// TODO May want to continue
return err
}
}
// Subscribe to changes in each attached inline-certificate config entry
for _, ref := range listener.Certificates {
ctx, cancel := context.WithCancel(ctx)
seenRefs[ref] = struct{}{}
snap.APIGateway.Certificates.InitWatch(ref, cancel)
err := h.subscribeToConfigEntry(ctx, ref.Kind, ref.Name, inlineCertificateConfigWatchID)
if err != nil {
// TODO May want to continue
return err
}
}
}
// Unsubscribe from any config entries that are no longer attached
snap.APIGateway.HTTPRoutes.ForEachKey(func(ref structs.ResourceReference) bool {
if _, ok := seenRefs[ref]; !ok {
snap.APIGateway.Upstreams.delete(ref)
snap.APIGateway.UpstreamsSet.delete(ref)
snap.APIGateway.HTTPRoutes.CancelWatch(ref)
}
return true
})
snap.APIGateway.TCPRoutes.ForEachKey(func(ref structs.ResourceReference) bool {
if _, ok := seenRefs[ref]; !ok {
snap.APIGateway.Upstreams.delete(ref)
snap.APIGateway.UpstreamsSet.delete(ref)
snap.APIGateway.TCPRoutes.CancelWatch(ref)
}
return true
})
snap.APIGateway.Certificates.ForEachKey(func(ref structs.ResourceReference) bool {
if _, ok := seenRefs[ref]; !ok {
snap.APIGateway.Certificates.CancelWatch(ref)
}
return true
})
snap.APIGateway.BoundGatewayConfigLoaded = true
break
case *structs.APIGatewayConfigEntry:
snap.APIGateway.GatewayConfig = gwConf
for _, listener := range gwConf.Listeners {
snap.APIGateway.Listeners[listener.Name] = listener
}
snap.APIGateway.GatewayConfigLoaded = true
break
default:
return fmt.Errorf("invalid type for config entry: %T", resp.Entry)
}
return h.watchIngressLeafCert(ctx, snap)
}
// handleInlineCertConfigUpdate stores the certificate for the gateway
func (h *handlerAPIGateway) handleInlineCertConfigUpdate(_ context.Context, u UpdateEvent, snap *ConfigSnapshot) error {
resp, ok := u.Result.(*structs.ConfigEntryResponse)
if !ok {
return fmt.Errorf("invalid type for response: %T", u.Result)
} else if resp.Entry == nil {
return nil
}
cfg, ok := resp.Entry.(*structs.InlineCertificateConfigEntry)
if !ok {
return fmt.Errorf("invalid type for config entry: %T", resp.Entry)
}
ref := structs.ResourceReference{
Kind: cfg.GetKind(),
Name: cfg.GetName(),
EnterpriseMeta: *cfg.GetEnterpriseMeta(),
}
snap.APIGateway.Certificates.Set(ref, cfg)
return nil
}
// handleRouteConfigUpdate builds the list of upstreams for services on
// the route and watches the related discovery chains.
func (h *handlerAPIGateway) handleRouteConfigUpdate(ctx context.Context, u UpdateEvent, snap *ConfigSnapshot) error {
resp, ok := u.Result.(*structs.ConfigEntryResponse)
if !ok {
return fmt.Errorf("invalid type for response: %T", u.Result)
} else if resp.Entry == nil {
return nil
}
ref := structs.ResourceReference{
Kind: resp.Entry.GetKind(),
Name: resp.Entry.GetName(),
EnterpriseMeta: *resp.Entry.GetEnterpriseMeta(),
}
seenUpstreamIDs := make(upstreamIDSet)
upstreams := make(map[APIGatewayListenerKey]structs.Upstreams)
switch route := resp.Entry.(type) {
case *structs.HTTPRouteConfigEntry:
snap.APIGateway.HTTPRoutes.Set(ref, route)
for _, rule := range route.Rules {
for _, service := range rule.Services {
for _, listener := range snap.APIGateway.Listeners {
shouldBind := false
for _, parent := range route.Parents {
if h.referenceIsForListener(parent, listener, snap) {
shouldBind = true
break
}
}
if !shouldBind {
continue
}
upstream := structs.Upstream{
DestinationName: service.Name,
DestinationNamespace: service.NamespaceOrDefault(),
DestinationPartition: service.PartitionOrDefault(),
LocalBindPort: listener.Port,
// TODO IngressHosts: g.Hosts,
// Pass the protocol that was configured on the listener in order
// to force that protocol on the Envoy listener.
Config: map[string]interface{}{
"protocol": "http",
},
}
listenerKey := APIGatewayListenerKey{Protocol: string(listener.Protocol), Port: listener.Port}
upstreams[listenerKey] = append(upstreams[listenerKey], upstream)
}
upstreamID := NewUpstreamIDFromServiceName(service.ServiceName())
seenUpstreamIDs[upstreamID] = struct{}{}
watchOpts := discoveryChainWatchOpts{
id: upstreamID,
name: service.Name,
namespace: service.NamespaceOrDefault(),
partition: service.PartitionOrDefault(),
datacenter: h.stateConfig.source.Datacenter,
}
handler := &handlerUpstreams{handlerState: h.handlerState}
if err := handler.watchDiscoveryChain(ctx, snap, watchOpts); err != nil {
return fmt.Errorf("failed to watch discovery chain for %s: %w", upstreamID, err)
}
}
}
case *structs.TCPRouteConfigEntry:
snap.APIGateway.TCPRoutes.Set(ref, route)
for _, service := range route.Services {
upstreamID := NewUpstreamIDFromServiceName(service.ServiceName())
seenUpstreamIDs.add(upstreamID)
// For each listener, check if this route should bind and, if so, create an upstream.
for _, listener := range snap.APIGateway.Listeners {
shouldBind := false
for _, parent := range route.Parents {
if h.referenceIsForListener(parent, listener, snap) {
shouldBind = true
break
}
}
if !shouldBind {
continue
}
upstream := structs.Upstream{
DestinationName: service.Name,
DestinationNamespace: service.NamespaceOrDefault(),
DestinationPartition: service.PartitionOrDefault(),
LocalBindPort: listener.Port,
// Pass the protocol that was configured on the ingress listener in order
// to force that protocol on the Envoy listener.
Config: map[string]interface{}{
"protocol": "tcp",
},
}
listenerKey := APIGatewayListenerKey{Protocol: string(listener.Protocol), Port: listener.Port}
upstreams[listenerKey] = append(upstreams[listenerKey], upstream)
}
watchOpts := discoveryChainWatchOpts{
id: upstreamID,
name: service.Name,
namespace: service.NamespaceOrDefault(),
partition: service.PartitionOrDefault(),
datacenter: h.stateConfig.source.Datacenter,
}
handler := &handlerUpstreams{handlerState: h.handlerState}
if err := handler.watchDiscoveryChain(ctx, snap, watchOpts); err != nil {
return fmt.Errorf("failed to watch discovery chain for %s: %w", upstreamID, err)
}
}
default:
return fmt.Errorf("invalid type for config entry: %T", resp.Entry)
}
for listener, set := range upstreams {
snap.APIGateway.Upstreams.set(ref, listener, set)
}
snap.APIGateway.UpstreamsSet.set(ref, seenUpstreamIDs)
//snap.APIGateway.Hosts = TODO
snap.APIGateway.AreHostsSet = true
// Stop watching any upstreams and discovery chains that have become irrelevant
for upstreamID, cancelDiscoChain := range snap.APIGateway.WatchedDiscoveryChains {
if snap.APIGateway.UpstreamsSet.hasUpstream(upstreamID) {
continue
}
for targetID, cancelUpstream := range snap.APIGateway.WatchedUpstreams[upstreamID] {
cancelUpstream()
delete(snap.APIGateway.WatchedUpstreams[upstreamID], targetID)
delete(snap.APIGateway.WatchedUpstreamEndpoints[upstreamID], targetID)
if targetUID := NewUpstreamIDFromTargetID(targetID); targetUID.Peer != "" {
snap.APIGateway.PeerUpstreamEndpoints.CancelWatch(targetUID)
snap.APIGateway.UpstreamPeerTrustBundles.CancelWatch(targetUID.Peer)
}
}
cancelDiscoChain()
delete(snap.APIGateway.WatchedDiscoveryChains, upstreamID)
}
return nil
}
// referenceIsForListener returns whether the provided structs.ResourceReference
// targets the provided structs.APIGatewayListener. For this to be true, the kind
// and name must match the structs.APIGatewayConfigEntry containing the listener,
// and the reference must specify either no section name or the name of the listener
// as the section name.
//
// TODO This would probably be more generally useful as a helper in the structs pkg
func (h *handlerAPIGateway) referenceIsForListener(ref structs.ResourceReference, listener structs.APIGatewayListener, snap *ConfigSnapshot) bool {
if ref.Kind != structs.APIGateway && ref.Kind != "" {
return false
}
if ref.Name != snap.APIGateway.GatewayConfig.Name {
return false
}
return ref.SectionName == "" || ref.SectionName == listener.Name
}
func (h *handlerAPIGateway) watchIngressLeafCert(ctx context.Context, snap *ConfigSnapshot) error {
// Note that we DON'T test for TLS.enabled because we need a leaf cert for the
// gateway even without TLS to use as a client cert.
if !snap.APIGateway.GatewayConfigLoaded {
return nil
}
// Watch the leaf cert
if snap.APIGateway.LeafCertWatchCancel != nil {
snap.APIGateway.LeafCertWatchCancel()
}
ctx, cancel := context.WithCancel(ctx)
err := h.dataSources.LeafCertificate.Notify(ctx, &cachetype.ConnectCALeafRequest{
Datacenter: h.source.Datacenter,
Token: h.token,
Service: h.service,
EnterpriseMeta: h.proxyID.EnterpriseMeta,
}, leafWatchID, h.ch)
if err != nil {
cancel()
return err
}
snap.APIGateway.LeafCertWatchCancel = cancel
return nil
}