open-consul/agent/submatview/local_materializer.go
Daniel Upton 497df1ca3b proxycfg: server-local config entry data sources
This is the OSS portion of enterprise PR 2056.

This commit provides server-local implementations of the proxycfg.ConfigEntry
and proxycfg.ConfigEntryList interfaces, that source data from streaming events.

It makes use of the LocalMaterializer type introduced for peering replication,
adding the necessary support for authorization.

It also adds support for "wildcard" subscriptions (within a topic) to the event
publisher, as this is needed to fetch service-resolvers for all services when
configuring mesh gateways.

Currently, events will be emitted for just the ingress-gateway, service-resolver,
and mesh config entry types, as these are the only entries required by proxycfg
— the events will be emitted on topics named IngressGateway, ServiceResolver,
and MeshConfig topics respectively.

Though these events will only be consumed "locally" for now, they can also be
consumed via the gRPC endpoint (confirmed using grpcurl) so using them from
client agents should be a case of swapping the LocalMaterializer for an
RPCMaterializer.
2022-07-04 10:48:36 +01:00

136 lines
3.3 KiB
Go

package submatview
import (
"context"
"errors"
"github.com/hashicorp/consul/acl"
"github.com/hashicorp/consul/acl/resolver"
"github.com/hashicorp/consul/agent/consul/state"
"github.com/hashicorp/consul/agent/consul/stream"
"github.com/hashicorp/consul/lib/retry"
"github.com/hashicorp/consul/proto/pbsubscribe"
)
// LocalMaterializer is a materializer for a stream of events
// and manages the local subscription to the event publisher
// until the cache result is discarded when its TTL expires.
type LocalMaterializer struct {
deps LocalMaterializerDeps
retryWaiter *retry.Waiter
handler eventHandler
mat *materializer
}
type LocalMaterializerDeps struct {
Deps
Backend LocalBackend
ACLResolver ACLResolver
}
var _ Materializer = (*LocalMaterializer)(nil)
type LocalBackend interface {
Subscribe(req *stream.SubscribeRequest) (*stream.Subscription, error)
}
//go:generate mockery --name ACLResolver --inpackage
type ACLResolver interface {
ResolveTokenAndDefaultMeta(token string, entMeta *acl.EnterpriseMeta, authzContext *acl.AuthorizerContext) (resolver.Result, error)
}
func NewLocalMaterializer(deps LocalMaterializerDeps) *LocalMaterializer {
m := LocalMaterializer{
deps: deps,
mat: newMaterializer(deps.Logger, deps.View, deps.Waiter),
}
return &m
}
// Query implements Materializer
func (m *LocalMaterializer) Query(ctx context.Context, minIndex uint64) (Result, error) {
return m.mat.query(ctx, minIndex)
}
// Run receives events from a local subscription backend and sends them to the View.
// It runs until ctx is cancelled, so it is expected to be run in a goroutine.
// Mirrors implementation of RPCMaterializer.
//
// Run implements Materializer
func (m *LocalMaterializer) Run(ctx context.Context) {
for {
req := m.deps.Request(m.mat.currentIndex())
err := m.subscribeOnce(ctx, req)
if ctx.Err() != nil {
return
}
m.mat.handleError(req, err)
if err := m.mat.retryWaiter.Wait(ctx); err != nil {
return
}
}
}
// subscribeOnce opens a new subscription to a local backend and runs
// for its lifetime or until the view is closed.
func (m *LocalMaterializer) subscribeOnce(ctx context.Context, req *pbsubscribe.SubscribeRequest) error {
ctx, cancel := context.WithCancel(ctx)
defer cancel()
m.handler = initialHandler(req.Index)
entMeta := req.EnterpriseMeta()
authz, err := m.deps.ACLResolver.ResolveTokenAndDefaultMeta(req.Token, &entMeta, nil)
if err != nil {
return err
}
subReq, err := state.PBToStreamSubscribeRequest(req, entMeta)
if err != nil {
return err
}
sub, err := m.deps.Backend.Subscribe(subReq)
if err != nil {
return err
}
defer sub.Unsubscribe()
for {
event, err := sub.Next(ctx)
switch {
case errors.Is(err, stream.ErrSubForceClosed):
m.deps.Logger.Trace("subscription reset by server")
return err
case err != nil:
return err
}
if !event.Payload.HasReadPermission(authz) {
continue
}
e := event.Payload.ToSubscriptionEvent(event.Index)
m.handler, err = m.handler(m, e)
if err != nil {
m.mat.reset()
return err
}
}
}
// updateView implements viewState
func (m *LocalMaterializer) updateView(events []*pbsubscribe.Event, index uint64) error {
return m.mat.updateView(events, index)
}
// reset implements viewState
func (m *LocalMaterializer) reset() {
m.mat.reset()
}