consul/agent/grpc-external/services/peerstream/subscription_blocking.go
Dan Upton b9e525d689
grpc: rename public/private directories to external/internal (#13721)
Previously, public referred to gRPC services that are both exposed on
the dedicated gRPC port and have their definitions in the proto-public
directory (so were considered usable by 3rd parties). Whereas private
referred to services on the multiplexed server port that are only usable
by agents and other servers.

Now, we're splitting these definitions, such that external/internal
refers to the port and public/private refers to whether they can be used
by 3rd parties.

This is necessary because the peering replication API needs to be
exposed on the dedicated port, but is not (yet) suitable for use by 3rd
parties.
2022-07-13 16:33:48 +01:00

109 lines
3.4 KiB
Go

package peerstream
import (
"context"
"errors"
"fmt"
"time"
"github.com/hashicorp/go-memdb"
"github.com/hashicorp/consul/agent/cache"
"github.com/hashicorp/consul/agent/structs"
"github.com/hashicorp/consul/lib/retry"
"github.com/hashicorp/consul/proto/pbservice"
)
// This file contains direct state store functions that need additional
// management to have them emit events. Ideally these would go through
// streaming machinery instead to be cheaper.
func (m *subscriptionManager) notifyExportedServicesForPeerID(ctx context.Context, state *subscriptionState, peerID string) {
// syncSubscriptionsAndBlock ensures that the subscriptions to the subscription backend
// match the list of services exported to the peer.
m.syncViaBlockingQuery(ctx, "exported-services", func(ctx context.Context, store StateStore, ws memdb.WatchSet) (interface{}, error) {
// Get exported services for peer id
_, list, err := store.ExportedServicesForPeer(ws, peerID, m.config.Datacenter)
if err != nil {
return nil, fmt.Errorf("failed to watch exported services for peer %q: %w", peerID, err)
}
return list, nil
}, subExportedServiceList, state.updateCh)
}
// TODO: add a new streaming subscription type to list-by-kind-and-partition since we're getting evictions
func (m *subscriptionManager) notifyMeshGatewaysForPartition(ctx context.Context, state *subscriptionState, partition string) {
m.syncViaBlockingQuery(ctx, "mesh-gateways", func(ctx context.Context, store StateStore, ws memdb.WatchSet) (interface{}, error) {
// Fetch our current list of all mesh gateways.
entMeta := structs.DefaultEnterpriseMetaInPartition(partition)
idx, nodes, err := store.ServiceDump(ws, structs.ServiceKindMeshGateway, true, entMeta, structs.DefaultPeerKeyword)
if err != nil {
return nil, fmt.Errorf("failed to watch mesh gateways services for partition %q: %w", partition, err)
}
if idx == 0 {
idx = 1
}
// convert back to a protobuf flavor
result := &pbservice.IndexedCheckServiceNodes{
Index: idx,
Nodes: make([]*pbservice.CheckServiceNode, len(nodes)),
}
for i, csn := range nodes {
result.Nodes[i] = pbservice.NewCheckServiceNodeFromStructs(&csn)
}
return result, nil
}, subMeshGateway+partition, state.updateCh)
}
func (m *subscriptionManager) syncViaBlockingQuery(
ctx context.Context,
queryType string,
queryFn func(ctx context.Context, store StateStore, ws memdb.WatchSet) (interface{}, error),
correlationID string,
updateCh chan<- cache.UpdateEvent,
) {
waiter := &retry.Waiter{
MinFailures: 1,
Factor: 500 * time.Millisecond,
MaxWait: 60 * time.Second,
Jitter: retry.NewJitter(100),
}
logger := m.logger
if queryType != "" {
logger = m.logger.With("queryType", queryType)
}
store := m.getStore()
for {
ws := memdb.NewWatchSet()
ws.Add(store.AbandonCh())
ws.Add(ctx.Done())
if result, err := queryFn(ctx, store, ws); err != nil {
logger.Error("failed to sync from query", "error", err)
} else {
// Block for any changes to the state store.
updateCh <- cache.UpdateEvent{
CorrelationID: correlationID,
Result: result,
}
ws.WatchCtx(ctx)
}
if err := waiter.Wait(ctx); err != nil && !errors.Is(err, context.Canceled) && !errors.Is(err, context.DeadlineExceeded) {
logger.Error("failed to wait before re-trying sync", "error", err)
}
select {
case <-ctx.Done():
return
default:
}
}
}