open-consul/agent/proxycfg/state.go
R.B. Boyer cc4733e60d
proxycfg: change how various proxycfg test helpers for making ConfigSnapshot copies works to be more correct and less error prone (#12531)
Prior to this PR for the envoy xDS golden tests in the agent/xds package we
were hand-creating a proxycfg.ConfigSnapshot structure in the proper format for
input to the xDS generator. Over time this intermediate structure has gotten
trickier to build correctly for the various tests.

This PR proposes to switch to using the existing mechanism for turning a
structs.NodeService and a sequence of cache.UpdateEvent copies into a
proxycfg.ConfigSnapshot, as that is less error prone to construct and aligns
more with how the data arrives.

NOTE: almost all of this is in test-related code. I tried super hard to craft
correct event inputs to get the golden files to be the same, or similar enough
after construction to feel ok that i recreated the spirit of the original test
cases.
2022-03-07 11:47:14 -06:00

462 lines
15 KiB
Go

package proxycfg
import (
"context"
"errors"
"fmt"
"net"
"reflect"
"time"
"github.com/hashicorp/go-hclog"
"github.com/mitchellh/copystructure"
"github.com/hashicorp/consul/agent/cache"
cachetype "github.com/hashicorp/consul/agent/cache-types"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/consul/logging"
)
type CacheNotifier interface {
Notify(ctx context.Context, t string, r cache.Request,
correlationID string, ch chan<- cache.UpdateEvent) error
}
type Health interface {
Notify(ctx context.Context, req structs.ServiceSpecificRequest, correlationID string, ch chan<- cache.UpdateEvent) error
}
const (
coalesceTimeout = 200 * time.Millisecond
rootsWatchID = "roots"
leafWatchID = "leaf"
intentionsWatchID = "intentions"
serviceListWatchID = "service-list"
federationStateListGatewaysWatchID = "federation-state-list-mesh-gateways"
consulServerListWatchID = "consul-server-list"
datacentersWatchID = "datacenters"
serviceResolversWatchID = "service-resolvers"
gatewayServicesWatchID = "gateway-services"
gatewayConfigWatchID = "gateway-config"
externalServiceIDPrefix = "external-service:"
serviceLeafIDPrefix = "service-leaf:"
serviceConfigIDPrefix = "service-config:"
serviceResolverIDPrefix = "service-resolver:"
serviceIntentionsIDPrefix = "service-intentions:"
intentionUpstreamsID = "intention-upstreams"
meshConfigEntryID = "mesh"
svcChecksWatchIDPrefix = cachetype.ServiceHTTPChecksName + ":"
preparedQueryIDPrefix = string(structs.UpstreamDestTypePreparedQuery) + ":"
defaultPreparedQueryPollInterval = 30 * time.Second
)
type stateConfig struct {
logger hclog.Logger
source *structs.QuerySource
cache CacheNotifier
health Health
dnsConfig DNSConfig
serverSNIFn ServerSNIFunc
intentionDefaultAllow bool
}
// state holds all the state needed to maintain the config for a registered
// connect-proxy service. When a proxy registration is changed, the entire state
// is discarded and a new one created.
type state struct {
logger hclog.Logger
serviceInstance serviceInstance
handler kindHandler
// cancel is set by Watch and called by Close to stop the goroutine started
// in Watch.
cancel func()
ch chan cache.UpdateEvent
snapCh chan ConfigSnapshot
reqCh chan chan *ConfigSnapshot
}
type DNSConfig struct {
Domain string
AltDomain string
}
type ServerSNIFunc func(dc, nodeName string) string
type serviceInstance struct {
kind structs.ServiceKind
service string
proxyID structs.ServiceID
address string
port int
meta map[string]string
taggedAddresses map[string]structs.ServiceAddress
proxyCfg structs.ConnectProxyConfig
token string
}
func copyProxyConfig(ns *structs.NodeService) (structs.ConnectProxyConfig, error) {
if ns == nil {
return structs.ConnectProxyConfig{}, nil
}
// Copy the config map
proxyCfgRaw, err := copystructure.Copy(ns.Proxy)
if err != nil {
return structs.ConnectProxyConfig{}, err
}
proxyCfg, ok := proxyCfgRaw.(structs.ConnectProxyConfig)
if !ok {
return structs.ConnectProxyConfig{}, errors.New("failed to copy proxy config")
}
// we can safely modify these since we just copied them
for idx := range proxyCfg.Upstreams {
us := &proxyCfg.Upstreams[idx]
if us.DestinationType != structs.UpstreamDestTypePreparedQuery {
// default the upstreams target namespace and partition to those of the proxy
// doing this here prevents needing much more complex logic a bunch of other
// places and makes tracking these upstreams simpler as we can dedup them
// with the maps tracking upstream ids being watched.
if us.DestinationPartition == "" {
proxyCfg.Upstreams[idx].DestinationPartition = ns.EnterpriseMeta.PartitionOrDefault()
}
if us.DestinationNamespace == "" {
proxyCfg.Upstreams[idx].DestinationNamespace = ns.EnterpriseMeta.NamespaceOrDefault()
}
}
}
return proxyCfg, nil
}
// newState populates the state struct by copying relevant fields from the
// NodeService and Token. We copy so that we can use them in a separate
// goroutine later without reasoning about races with the NodeService passed
// (especially for embedded fields like maps and slices).
//
// The returned state needs its required dependencies to be set before Watch
// can be called.
func newState(ns *structs.NodeService, token string, config stateConfig) (*state, error) {
// 10 is fairly arbitrary here but allow for the 3 mandatory and a
// reasonable number of upstream watches to all deliver their initial
// messages in parallel without blocking the cache.Notify loops. It's not a
// huge deal if we do for a short period so we don't need to be more
// conservative to handle larger numbers of upstreams correctly but gives
// some head room for normal operation to be non-blocking in most typical
// cases.
ch := make(chan cache.UpdateEvent, 10)
s, err := newServiceInstanceFromNodeService(ns, token)
if err != nil {
return nil, err
}
handler, err := newKindHandler(config, s, ch)
if err != nil {
return nil, err
}
return &state{
logger: config.logger.With("proxy", s.proxyID, "kind", s.kind),
serviceInstance: s,
handler: handler,
ch: ch,
snapCh: make(chan ConfigSnapshot, 1),
reqCh: make(chan chan *ConfigSnapshot, 1),
}, nil
}
func newKindHandler(config stateConfig, s serviceInstance, ch chan cache.UpdateEvent) (kindHandler, error) {
var handler kindHandler
h := handlerState{stateConfig: config, serviceInstance: s, ch: ch}
switch s.kind {
case structs.ServiceKindConnectProxy:
handler = &handlerConnectProxy{handlerState: h}
case structs.ServiceKindTerminatingGateway:
h.stateConfig.logger = config.logger.Named(logging.TerminatingGateway)
handler = &handlerTerminatingGateway{handlerState: h}
case structs.ServiceKindMeshGateway:
h.stateConfig.logger = config.logger.Named(logging.MeshGateway)
handler = &handlerMeshGateway{handlerState: h}
case structs.ServiceKindIngressGateway:
handler = &handlerIngressGateway{handlerState: h}
default:
return nil, errors.New("not a connect-proxy, terminating-gateway, mesh-gateway, or ingress-gateway")
}
return handler, nil
}
func newServiceInstanceFromNodeService(ns *structs.NodeService, token string) (serviceInstance, error) {
proxyCfg, err := copyProxyConfig(ns)
if err != nil {
return serviceInstance{}, err
}
taggedAddresses := make(map[string]structs.ServiceAddress)
for k, v := range ns.TaggedAddresses {
taggedAddresses[k] = v
}
meta := make(map[string]string)
for k, v := range ns.Meta {
meta[k] = v
}
return serviceInstance{
kind: ns.Kind,
service: ns.Service,
proxyID: ns.CompoundServiceID(),
address: ns.Address,
port: ns.Port,
meta: meta,
taggedAddresses: taggedAddresses,
proxyCfg: proxyCfg,
token: token,
}, nil
}
type kindHandler interface {
initialize(ctx context.Context) (ConfigSnapshot, error)
handleUpdate(ctx context.Context, u cache.UpdateEvent, snap *ConfigSnapshot) error
}
// Watch initialized watches on all necessary cache data for the current proxy
// registration state and returns a chan to observe updates to the
// ConfigSnapshot that contains all necessary config state. The chan is closed
// when the state is Closed.
func (s *state) Watch() (<-chan ConfigSnapshot, error) {
var ctx context.Context
ctx, s.cancel = context.WithCancel(context.Background())
snap, err := s.handler.initialize(ctx)
if err != nil {
s.cancel()
return nil, err
}
go s.run(ctx, &snap)
return s.snapCh, nil
}
// Close discards the state and stops any long-running watches.
func (s *state) Close() error {
if s.cancel != nil {
s.cancel()
}
return nil
}
type handlerState struct {
stateConfig // TODO: un-embed
serviceInstance // TODO: un-embed
ch chan cache.UpdateEvent
}
func newConfigSnapshotFromServiceInstance(s serviceInstance, config stateConfig) ConfigSnapshot {
// TODO: use serviceInstance type in ConfigSnapshot
return ConfigSnapshot{
Kind: s.kind,
Service: s.service,
ProxyID: s.proxyID,
Address: s.address,
Port: s.port,
ServiceMeta: s.meta,
TaggedAddresses: s.taggedAddresses,
Proxy: s.proxyCfg,
Datacenter: config.source.Datacenter,
Locality: GatewayKey{Datacenter: config.source.Datacenter, Partition: s.proxyID.PartitionOrDefault()},
ServerSNIFn: config.serverSNIFn,
IntentionDefaultAllow: config.intentionDefaultAllow,
}
}
func (s *state) run(ctx context.Context, snap *ConfigSnapshot) {
// Close the channel we return from Watch when we stop so consumers can stop
// watching and clean up their goroutines. It's important we do this here and
// not in Close since this routine sends on this chan and so might panic if it
// gets closed from another goroutine.
defer close(s.snapCh)
// This turns out to be really fiddly/painful by just using time.Timer.C
// directly in the code below since you can't detect when a timer is stopped
// vs waiting in order to know to reset it. So just use a chan to send
// ourselves messages.
sendCh := make(chan struct{})
var coalesceTimer *time.Timer
for {
select {
case <-ctx.Done():
return
case u := <-s.ch:
s.logger.Trace("A blocking query returned; handling snapshot update", "correlationID", u.CorrelationID)
if err := s.handler.handleUpdate(ctx, u, snap); err != nil {
s.logger.Error("Failed to handle update from watch",
"id", u.CorrelationID, "error", err,
)
continue
}
case <-sendCh:
// Allow the next change to trigger a send
coalesceTimer = nil
// Make a deep copy of snap so we don't mutate any of the embedded structs
// etc on future updates.
snapCopy, err := snap.Clone()
if err != nil {
s.logger.Error("Failed to copy config snapshot for proxy", "error", err)
continue
}
select {
// Try to send
case s.snapCh <- *snapCopy:
s.logger.Trace("Delivered new snapshot to proxy config watchers")
// Skip rest of loop - there is nothing to send since nothing changed on
// this iteration
continue
// Avoid blocking if a snapshot is already buffered in snapCh as this can result in a deadlock.
// See PR #9689 for more details.
default:
s.logger.Trace("Failed to deliver new snapshot to proxy config watchers")
// Reset the timer to retry later. This is to ensure we attempt to redeliver the updated snapshot shortly.
coalesceTimer = time.AfterFunc(coalesceTimeout, func() {
sendCh <- struct{}{}
})
// Do not reset coalesceTimer since we just queued a timer-based refresh
continue
}
case replyCh := <-s.reqCh:
s.logger.Trace("A proxy config snapshot was requested")
if !snap.Valid() {
// Not valid yet just respond with nil and move on to next task.
replyCh <- nil
s.logger.Trace("The proxy's config snapshot is not valid yet")
continue
}
// Make a deep copy of snap so we don't mutate any of the embedded structs
// etc on future updates.
snapCopy, err := snap.Clone()
if err != nil {
s.logger.Error("Failed to copy config snapshot for proxy", "error", err)
continue
}
replyCh <- snapCopy
// Skip rest of loop - there is nothing to send since nothing changed on
// this iteration
continue
}
// Check if snap is complete enough to be a valid config to deliver to a
// proxy yet.
if snap.Valid() {
// Don't send it right away, set a short timer that will wait for updates
// from any of the other cache values and deliver them all together.
if coalesceTimer == nil {
coalesceTimer = time.AfterFunc(coalesceTimeout, func() {
// This runs in another goroutine so we can't just do the send
// directly here as access to snap is racy. Instead, signal the main
// loop above.
sendCh <- struct{}{}
})
}
}
}
}
// CurrentSnapshot synchronously returns the current ConfigSnapshot if there is
// one ready. If we don't have one yet because not all necessary parts have been
// returned (i.e. both roots and leaf cert), nil is returned.
func (s *state) CurrentSnapshot() *ConfigSnapshot {
// Make a chan for the response to be sent on
ch := make(chan *ConfigSnapshot, 1)
s.reqCh <- ch
// Wait for the response
return <-ch
}
// Changed returns whether or not the passed NodeService has had any of the
// fields we care about for config state watching changed or a different token.
func (s *state) Changed(ns *structs.NodeService, token string) bool {
if ns == nil {
return true
}
proxyCfg, err := copyProxyConfig(ns)
if err != nil {
s.logger.Warn("Failed to parse proxy config and will treat the new service as unchanged")
}
i := s.serviceInstance
return ns.Kind != i.kind ||
i.proxyID != ns.CompoundServiceID() ||
i.address != ns.Address ||
i.port != ns.Port ||
!reflect.DeepEqual(i.proxyCfg, proxyCfg) ||
i.token != token
}
// hostnameEndpoints returns all CheckServiceNodes that have hostnames instead of IPs as the address.
// Envoy cannot resolve hostnames provided through EDS, so we exclusively use CDS for these clusters.
// If there is a mix of hostnames and addresses we exclusively use the hostnames, since clusters cannot discover
// services with both EDS and DNS.
func hostnameEndpoints(logger hclog.Logger, localKey GatewayKey, nodes structs.CheckServiceNodes) structs.CheckServiceNodes {
var (
hasIP bool
hasHostname bool
resp structs.CheckServiceNodes
)
for _, n := range nodes {
_, addr, _ := n.BestAddress(!localKey.Matches(n.Node.Datacenter, n.Node.PartitionOrDefault()))
if net.ParseIP(addr) != nil {
hasIP = true
continue
}
hasHostname = true
resp = append(resp, n)
}
if hasHostname && hasIP {
dc := nodes[0].Node.Datacenter
sn := nodes[0].Service.CompoundServiceName()
logger.Warn("service contains instances with mix of hostnames and IP addresses; only hostnames will be passed to Envoy",
"dc", dc, "service", sn.String())
}
return resp
}
type gatewayWatchOpts struct {
notifier CacheNotifier
notifyCh chan cache.UpdateEvent
source structs.QuerySource
token string
key GatewayKey
upstreamID UpstreamID
}
func watchMeshGateway(ctx context.Context, opts gatewayWatchOpts) error {
return opts.notifier.Notify(ctx, cachetype.InternalServiceDumpName, &structs.ServiceDumpRequest{
Datacenter: opts.key.Datacenter,
QueryOptions: structs.QueryOptions{Token: opts.token},
ServiceKind: structs.ServiceKindMeshGateway,
UseServiceKind: true,
Source: opts.source,
EnterpriseMeta: *structs.DefaultEnterpriseMetaInPartition(opts.key.Partition),
}, fmt.Sprintf("mesh-gateway:%s:%s", opts.key.String(), opts.upstreamID.String()), opts.notifyCh)
}