open-consul/agent/consul/state/config_entry.go

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package state
import (
"fmt"
"github.com/hashicorp/consul/agent/consul/discoverychain"
"github.com/hashicorp/consul/agent/structs"
memdb "github.com/hashicorp/go-memdb"
)
const (
configTableName = "config-entries"
)
// configTableSchema returns a new table schema used to store global
// config entries.
func configTableSchema() *memdb.TableSchema {
return &memdb.TableSchema{
Name: configTableName,
Indexes: map[string]*memdb.IndexSchema{
"id": &memdb.IndexSchema{
Name: "id",
AllowMissing: false,
Unique: true,
Indexer: &memdb.CompoundIndex{
Indexes: []memdb.Indexer{
&memdb.StringFieldIndex{
Field: "Kind",
Lowercase: true,
},
&memdb.StringFieldIndex{
Field: "Name",
Lowercase: true,
},
},
},
},
"kind": &memdb.IndexSchema{
Name: "kind",
AllowMissing: false,
Unique: false,
Indexer: &memdb.StringFieldIndex{
Field: "Kind",
Lowercase: true,
},
},
"link": &memdb.IndexSchema{
Name: "link",
AllowMissing: true,
Unique: false,
Indexer: &ConfigEntryLinkIndex{},
},
},
}
}
type ConfigEntryLinkIndex struct {
}
type discoveryChainConfigEntry interface {
structs.ConfigEntry
// ListRelatedServices returns a list of other names of services referenced
// in this config entry.
ListRelatedServices() []string
}
func (s *ConfigEntryLinkIndex) FromObject(obj interface{}) (bool, [][]byte, error) {
entry, ok := obj.(structs.ConfigEntry)
if !ok {
return false, nil, fmt.Errorf("object is not a ConfigEntry")
}
dcEntry, ok := entry.(discoveryChainConfigEntry)
if !ok {
return false, nil, nil
}
linkedServices := dcEntry.ListRelatedServices()
numLinks := len(linkedServices)
if numLinks == 0 {
return false, nil, nil
}
vals := make([][]byte, 0, numLinks)
for _, linkedService := range linkedServices {
vals = append(vals, []byte(linkedService+"\x00"))
}
return true, vals, nil
}
func (s *ConfigEntryLinkIndex) FromArgs(args ...interface{}) ([]byte, error) {
if len(args) != 1 {
return nil, fmt.Errorf("must provide only a single argument")
}
arg, ok := args[0].(string)
if !ok {
return nil, fmt.Errorf("argument must be a string: %#v", args[0])
}
// Add the null character as a terminator
arg += "\x00"
return []byte(arg), nil
}
func (s *ConfigEntryLinkIndex) PrefixFromArgs(args ...interface{}) ([]byte, error) {
val, err := s.FromArgs(args...)
if err != nil {
return nil, err
}
// Strip the null terminator, the rest is a prefix
n := len(val)
if n > 0 {
return val[:n-1], nil
}
return val, nil
}
func init() {
registerSchema(configTableSchema)
}
// ConfigEntries is used to pull all the config entries for the snapshot.
func (s *Snapshot) ConfigEntries() ([]structs.ConfigEntry, error) {
entries, err := s.tx.Get(configTableName, "id")
if err != nil {
return nil, err
}
var ret []structs.ConfigEntry
for wrapped := entries.Next(); wrapped != nil; wrapped = entries.Next() {
ret = append(ret, wrapped.(structs.ConfigEntry))
}
return ret, nil
}
// ConfigEntry is used when restoring from a snapshot.
func (s *Restore) ConfigEntry(c structs.ConfigEntry) error {
// Insert
if err := s.tx.Insert(configTableName, c); err != nil {
return fmt.Errorf("failed restoring config entry object: %s", err)
}
if err := indexUpdateMaxTxn(s.tx, c.GetRaftIndex().ModifyIndex, configTableName); err != nil {
return fmt.Errorf("failed updating index: %s", err)
}
return nil
}
// ConfigEntry is called to get a given config entry.
func (s *Store) ConfigEntry(ws memdb.WatchSet, kind, name string) (uint64, structs.ConfigEntry, error) {
tx := s.db.Txn(false)
defer tx.Abort()
return s.configEntryTxn(tx, ws, kind, name)
}
func (s *Store) configEntryTxn(tx *memdb.Txn, ws memdb.WatchSet, kind, name string) (uint64, structs.ConfigEntry, error) {
// Get the index
idx := maxIndexTxn(tx, configTableName)
// Get the existing config entry.
watchCh, existing, err := tx.FirstWatch(configTableName, "id", kind, name)
if err != nil {
return 0, nil, fmt.Errorf("failed config entry lookup: %s", err)
}
ws.Add(watchCh)
if existing == nil {
return idx, nil, nil
}
conf, ok := existing.(structs.ConfigEntry)
if !ok {
return 0, nil, fmt.Errorf("config entry %q (%s) is an invalid type: %T", name, kind, conf)
}
return idx, conf, nil
}
// ConfigEntries is called to get all config entry objects.
func (s *Store) ConfigEntries(ws memdb.WatchSet) (uint64, []structs.ConfigEntry, error) {
return s.ConfigEntriesByKind(ws, "")
}
// ConfigEntriesByKind is called to get all config entry objects with the given kind.
// If kind is empty, all config entries will be returned.
func (s *Store) ConfigEntriesByKind(ws memdb.WatchSet, kind string) (uint64, []structs.ConfigEntry, error) {
tx := s.db.Txn(false)
defer tx.Abort()
return s.configEntriesByKindTxn(tx, ws, kind)
}
func (s *Store) configEntriesByKindTxn(tx *memdb.Txn, ws memdb.WatchSet, kind string) (uint64, []structs.ConfigEntry, error) {
// Get the index
idx := maxIndexTxn(tx, configTableName)
// Lookup by kind, or all if kind is empty
var iter memdb.ResultIterator
var err error
if kind != "" {
iter, err = tx.Get(configTableName, "kind", kind)
} else {
iter, err = tx.Get(configTableName, "id")
}
if err != nil {
return 0, nil, fmt.Errorf("failed config entry lookup: %s", err)
}
ws.Add(iter.WatchCh())
var results []structs.ConfigEntry
for v := iter.Next(); v != nil; v = iter.Next() {
results = append(results, v.(structs.ConfigEntry))
}
return idx, results, nil
}
// EnsureConfigEntry is called to do an upsert of a given config entry.
func (s *Store) EnsureConfigEntry(idx uint64, conf structs.ConfigEntry) error {
tx := s.db.Txn(true)
defer tx.Abort()
if err := s.ensureConfigEntryTxn(tx, idx, conf); err != nil {
return err
}
tx.Commit()
return nil
}
// ensureConfigEntryTxn upserts a config entry inside of a transaction.
func (s *Store) ensureConfigEntryTxn(tx *memdb.Txn, idx uint64, conf structs.ConfigEntry) error {
// Check for existing configuration.
existing, err := tx.First(configTableName, "id", conf.GetKind(), conf.GetName())
if err != nil {
return fmt.Errorf("failed configuration lookup: %s", err)
}
raftIndex := conf.GetRaftIndex()
if existing != nil {
existingIdx := existing.(structs.ConfigEntry).GetRaftIndex()
raftIndex.CreateIndex = existingIdx.CreateIndex
raftIndex.ModifyIndex = existingIdx.ModifyIndex
} else {
raftIndex.CreateIndex = idx
}
raftIndex.ModifyIndex = idx
err = s.validateProposedConfigEntryInGraph(
tx,
idx,
conf.GetKind(),
conf.GetName(),
conf,
)
if err != nil {
return err // Err is already sufficiently decorated.
}
// Insert the config entry and update the index
if err := tx.Insert(configTableName, conf); err != nil {
return fmt.Errorf("failed inserting config entry: %s", err)
}
if err := indexUpdateMaxTxn(tx, idx, configTableName); err != nil {
return fmt.Errorf("failed updating index: %v", err)
}
return nil
}
// EnsureConfigEntryCAS is called to do a check-and-set upsert of a given config entry.
func (s *Store) EnsureConfigEntryCAS(idx, cidx uint64, conf structs.ConfigEntry) (bool, error) {
tx := s.db.Txn(true)
defer tx.Abort()
// Check for existing configuration.
existing, err := tx.First(configTableName, "id", conf.GetKind(), conf.GetName())
if err != nil {
return false, fmt.Errorf("failed configuration lookup: %s", err)
}
// Check if the we should do the set. A ModifyIndex of 0 means that
// we are doing a set-if-not-exists.
var existingIdx structs.RaftIndex
if existing != nil {
existingIdx = *existing.(structs.ConfigEntry).GetRaftIndex()
}
if cidx == 0 && existing != nil {
return false, nil
}
if cidx != 0 && existing == nil {
return false, nil
}
if existing != nil && cidx != 0 && cidx != existingIdx.ModifyIndex {
return false, nil
}
if err := s.ensureConfigEntryTxn(tx, idx, conf); err != nil {
return false, err
}
tx.Commit()
return true, nil
}
func (s *Store) DeleteConfigEntry(idx uint64, kind, name string) error {
tx := s.db.Txn(true)
defer tx.Abort()
// Try to retrieve the existing config entry.
existing, err := tx.First(configTableName, "id", kind, name)
if err != nil {
return fmt.Errorf("failed config entry lookup: %s", err)
}
if existing == nil {
return nil
}
err = s.validateProposedConfigEntryInGraph(
tx,
idx,
kind,
name,
nil,
)
if err != nil {
return err // Err is already sufficiently decorated.
}
// Delete the config entry from the DB and update the index.
if err := tx.Delete(configTableName, existing); err != nil {
return fmt.Errorf("failed removing check: %s", err)
}
if err := tx.Insert("index", &IndexEntry{configTableName, idx}); err != nil {
return fmt.Errorf("failed updating index: %s", err)
}
tx.Commit()
return nil
}
// validateProposedConfigEntryInGraph can be used to verify graph integrity for
// a proposed graph create/update/delete.
//
// This must be called before any mutations occur on the config entries table!
//
// May return *ConfigEntryGraphValidationError if there is a concern to surface
// to the caller that they can correct.
func (s *Store) validateProposedConfigEntryInGraph(
tx *memdb.Txn,
idx uint64,
kind, name string,
next structs.ConfigEntry,
) error {
validateAllChains := false
switch kind {
case structs.ProxyDefaults:
if name != structs.ProxyConfigGlobal {
return nil
}
validateAllChains = true
case structs.ServiceDefaults:
case structs.ServiceRouter:
case structs.ServiceSplitter:
case structs.ServiceResolver:
default:
return fmt.Errorf("unhandled kind %q during validation of %q", kind, name)
}
return s.validateProposedConfigEntryInServiceGraph(tx, idx, kind, name, next, validateAllChains)
}
var serviceGraphKinds = []string{
structs.ServiceRouter,
structs.ServiceSplitter,
structs.ServiceResolver,
}
func (s *Store) validateProposedConfigEntryInServiceGraph(
tx *memdb.Txn,
idx uint64,
kind, name string,
next structs.ConfigEntry,
validateAllChains bool,
) error {
// Collect all of the chains that could be affected by this change
// including our own.
checkChains := make(map[string]struct{})
if validateAllChains {
// Must be proxy-defaults/global.
// Check anything that has a discovery chain entry. In the future we could
// somehow omit the ones that have a default protocol configured.
for _, kind := range serviceGraphKinds {
_, entries, err := s.configEntriesByKindTxn(tx, nil, kind)
if err != nil {
return err
}
for _, entry := range entries {
checkChains[entry.GetName()] = struct{}{}
}
}
} else {
// Must be a single chain.
checkChains[name] = struct{}{}
iter, err := tx.Get(configTableName, "link", name)
for raw := iter.Next(); raw != nil; raw = iter.Next() {
entry := raw.(structs.ConfigEntry)
checkChains[entry.GetName()] = struct{}{}
}
if err != nil {
return err
}
}
overrides := map[structs.ConfigEntryKindName]structs.ConfigEntry{
{Kind: kind, Name: name}: next,
}
for chainName, _ := range checkChains {
if err := s.testCompileDiscoveryChain(tx, nil, chainName, overrides); err != nil {
return err
}
}
return nil
}
func (s *Store) testCompileDiscoveryChain(
tx *memdb.Txn,
ws memdb.WatchSet,
chainName string,
overrides map[structs.ConfigEntryKindName]structs.ConfigEntry,
) error {
_, speculativeEntries, err := s.readDiscoveryChainConfigEntriesTxn(tx, nil, chainName, overrides)
if err != nil {
return err
}
// Note we use an arbitrary namespace and datacenter as those would not
// currently affect the graph compilation in ways that matter here.
connect: fix failover through a mesh gateway to a remote datacenter (#6259) Failover is pushed entirely down to the data plane by creating envoy clusters and putting each successive destination in a different load assignment priority band. For example this shows that normally requests go to 1.2.3.4:8080 but when that fails they go to 6.7.8.9:8080: - name: foo load_assignment: cluster_name: foo policy: overprovisioning_factor: 100000 endpoints: - priority: 0 lb_endpoints: - endpoint: address: socket_address: address: 1.2.3.4 port_value: 8080 - priority: 1 lb_endpoints: - endpoint: address: socket_address: address: 6.7.8.9 port_value: 8080 Mesh gateways route requests based solely on the SNI header tacked onto the TLS layer. Envoy currently only lets you configure the outbound SNI header at the cluster layer. If you try to failover through a mesh gateway you ideally would configure the SNI value per endpoint, but that's not possible in envoy today. This PR introduces a simpler way around the problem for now: 1. We identify any target of failover that will use mesh gateway mode local or remote and then further isolate any resolver node in the compiled discovery chain that has a failover destination set to one of those targets. 2. For each of these resolvers we will perform a small measurement of comparative healths of the endpoints that come back from the health API for the set of primary target and serial failover targets. We walk the list of targets in order and if any endpoint is healthy we return that target, otherwise we move on to the next target. 3. The CDS and EDS endpoints both perform the measurements in (2) for the affected resolver nodes. 4. For CDS this measurement selects which TLS SNI field to use for the cluster (note the cluster is always going to be named for the primary target) 5. For EDS this measurement selects which set of endpoints will populate the cluster. Priority tiered failover is ignored. One of the big downsides to this approach to failover is that the failover detection and correction is going to be controlled by consul rather than deferring that entirely to the data plane as with the prior version. This also means that we are bound to only failover using official health signals and cannot make use of data plane signals like outlier detection to affect failover. In this specific scenario the lack of data plane signals is ok because the effectiveness is already muted by the fact that the ultimate destination endpoints will have their data plane signals scrambled when they pass through the mesh gateway wrapper anyway so we're not losing much. Another related fix is that we now use the endpoint health from the underlying service, not the health of the gateway (regardless of failover mode).
2019-08-05 18:30:35 +00:00
//
// TODO(rb): we should thread a better value than "dc1" and the throwaway trust domain down here as that is going to sometimes show up in user facing errors
req := discoverychain.CompileRequest{
ServiceName: chainName,
EvaluateInNamespace: "default",
EvaluateInDatacenter: "dc1",
EvaluateInTrustDomain: "b6fc9da3-03d4-4b5a-9134-c045e9b20152.consul",
UseInDatacenter: "dc1",
Entries: speculativeEntries,
}
_, err = discoverychain.Compile(req)
return err
}
// ReadDiscoveryChainConfigEntries will query for the full discovery chain for
// the provided service name. All relevant config entries will be recursively
// fetched and included in the result.
//
// Once returned, the caller still needs to assemble these into a useful graph
// structure.
func (s *Store) ReadDiscoveryChainConfigEntries(
ws memdb.WatchSet,
serviceName string,
) (uint64, *structs.DiscoveryChainConfigEntries, error) {
return s.readDiscoveryChainConfigEntries(ws, serviceName, nil)
}
// readDiscoveryChainConfigEntries will query for the full discovery chain for
// the provided service name. All relevant config entries will be recursively
// fetched and included in the result.
//
// If 'overrides' is provided then it will use entries in that map instead of
// the database to simulate the entries that go into a modified discovery chain
// without actually modifying it yet. Nil values are tombstones to simulate
// deleting an entry.
//
// Overrides is not mutated.
func (s *Store) readDiscoveryChainConfigEntries(
ws memdb.WatchSet,
serviceName string,
overrides map[structs.ConfigEntryKindName]structs.ConfigEntry,
) (uint64, *structs.DiscoveryChainConfigEntries, error) {
tx := s.db.Txn(false)
defer tx.Abort()
return s.readDiscoveryChainConfigEntriesTxn(tx, ws, serviceName, overrides)
}
func (s *Store) readDiscoveryChainConfigEntriesTxn(
tx *memdb.Txn,
ws memdb.WatchSet,
serviceName string,
overrides map[structs.ConfigEntryKindName]structs.ConfigEntry,
) (uint64, *structs.DiscoveryChainConfigEntries, error) {
res := structs.NewDiscoveryChainConfigEntries()
// Note that below we always look up splitters and resolvers in pairs, even
// in some circumstances where both are not strictly necessary.
//
// For now we'll just eat the cost of fetching pairs of splitter/resolver
// config entries even though we may not always need both. In the common
// case we will need the pair so there's not a big drive to optimize this
// here at this time.
// Both Splitters and Resolvers maps will contain placeholder nils until
// the end of this function to indicate "no such entry".
var (
todoSplitters = make(map[string]struct{})
todoResolvers = make(map[string]struct{})
todoDefaults = make(map[string]struct{})
)
// Grab the proxy defaults if they exist.
idx, proxy, err := s.getProxyConfigEntryTxn(tx, ws, structs.ProxyConfigGlobal, overrides)
if err != nil {
return 0, nil, err
} else if proxy != nil {
res.GlobalProxy = proxy
}
// At every step we'll need service defaults.
todoDefaults[serviceName] = struct{}{}
// first fetch the router, of which we only collect 1 per chain eval
_, router, err := s.getRouterConfigEntryTxn(tx, ws, serviceName, overrides)
if err != nil {
return 0, nil, err
} else if router != nil {
res.Routers[serviceName] = router
}
if router != nil {
for _, svc := range router.ListRelatedServices() {
todoSplitters[svc] = struct{}{}
}
} else {
// Next hop in the chain is the splitter.
todoSplitters[serviceName] = struct{}{}
}
for {
name, ok := anyKey(todoSplitters)
if !ok {
break
}
delete(todoSplitters, name)
if _, ok := res.Splitters[name]; ok {
continue // already fetched
}
// Yes, even for splitters.
todoDefaults[name] = struct{}{}
_, splitter, err := s.getSplitterConfigEntryTxn(tx, ws, name, overrides)
if err != nil {
return 0, nil, err
}
if splitter == nil {
res.Splitters[name] = nil
// Next hop in the chain is the resolver.
todoResolvers[name] = struct{}{}
continue
}
res.Splitters[name] = splitter
todoResolvers[name] = struct{}{}
for _, svc := range splitter.ListRelatedServices() {
// If there is no splitter, this will end up adding a resolver
// after another iteration.
todoSplitters[svc] = struct{}{}
}
}
for {
name, ok := anyKey(todoResolvers)
if !ok {
break
}
delete(todoResolvers, name)
if _, ok := res.Resolvers[name]; ok {
continue // already fetched
}
// And resolvers, too.
todoDefaults[name] = struct{}{}
_, resolver, err := s.getResolverConfigEntryTxn(tx, ws, name, overrides)
if err != nil {
return 0, nil, err
}
if resolver == nil {
res.Resolvers[name] = nil
continue
}
res.Resolvers[name] = resolver
for _, svc := range resolver.ListRelatedServices() {
todoResolvers[svc] = struct{}{}
}
}
for {
name, ok := anyKey(todoDefaults)
if !ok {
break
}
delete(todoDefaults, name)
if _, ok := res.Services[name]; ok {
continue // already fetched
}
_, entry, err := s.getServiceConfigEntryTxn(tx, ws, name, overrides)
if err != nil {
return 0, nil, err
}
if entry == nil {
res.Services[name] = nil
continue
}
res.Services[name] = entry
}
// Strip nils now that they are no longer necessary.
for name, entry := range res.Routers {
if entry == nil {
delete(res.Routers, name)
}
}
for name, entry := range res.Splitters {
if entry == nil {
delete(res.Splitters, name)
}
}
for name, entry := range res.Resolvers {
if entry == nil {
delete(res.Resolvers, name)
}
}
for name, entry := range res.Services {
if entry == nil {
delete(res.Services, name)
}
}
return idx, res, nil
}
// anyKey returns any key from the provided map if any exist. Useful for using
// a map as a simple work queue of sorts.
func anyKey(m map[string]struct{}) (string, bool) {
if len(m) == 0 {
return "", false
}
for k, _ := range m {
return k, true
}
return "", false
}
// getProxyConfigEntryTxn is a convenience method for fetching a
// proxy-defaults kind of config entry.
//
// If an override is returned the index returned will be 0.
func (s *Store) getProxyConfigEntryTxn(
tx *memdb.Txn,
ws memdb.WatchSet,
name string,
overrides map[structs.ConfigEntryKindName]structs.ConfigEntry,
) (uint64, *structs.ProxyConfigEntry, error) {
idx, entry, err := s.configEntryWithOverridesTxn(tx, ws, structs.ProxyDefaults, name, overrides)
if err != nil {
return 0, nil, err
} else if entry == nil {
return idx, nil, nil
}
proxy, ok := entry.(*structs.ProxyConfigEntry)
if !ok {
return 0, nil, fmt.Errorf("invalid service config type %T", entry)
}
return idx, proxy, nil
}
// getServiceConfigEntryTxn is a convenience method for fetching a
// service-defaults kind of config entry.
//
// If an override is returned the index returned will be 0.
func (s *Store) getServiceConfigEntryTxn(
tx *memdb.Txn,
ws memdb.WatchSet,
serviceName string,
overrides map[structs.ConfigEntryKindName]structs.ConfigEntry,
) (uint64, *structs.ServiceConfigEntry, error) {
idx, entry, err := s.configEntryWithOverridesTxn(tx, ws, structs.ServiceDefaults, serviceName, overrides)
if err != nil {
return 0, nil, err
} else if entry == nil {
return idx, nil, nil
}
service, ok := entry.(*structs.ServiceConfigEntry)
if !ok {
return 0, nil, fmt.Errorf("invalid service config type %T", entry)
}
return idx, service, nil
}
// getRouterConfigEntryTxn is a convenience method for fetching a
// service-router kind of config entry.
//
// If an override is returned the index returned will be 0.
func (s *Store) getRouterConfigEntryTxn(
tx *memdb.Txn,
ws memdb.WatchSet,
serviceName string,
overrides map[structs.ConfigEntryKindName]structs.ConfigEntry,
) (uint64, *structs.ServiceRouterConfigEntry, error) {
idx, entry, err := s.configEntryWithOverridesTxn(tx, ws, structs.ServiceRouter, serviceName, overrides)
if err != nil {
return 0, nil, err
} else if entry == nil {
return idx, nil, nil
}
router, ok := entry.(*structs.ServiceRouterConfigEntry)
if !ok {
return 0, nil, fmt.Errorf("invalid service config type %T", entry)
}
return idx, router, nil
}
// getSplitterConfigEntryTxn is a convenience method for fetching a
// service-splitter kind of config entry.
//
// If an override is returned the index returned will be 0.
func (s *Store) getSplitterConfigEntryTxn(
tx *memdb.Txn,
ws memdb.WatchSet,
serviceName string,
overrides map[structs.ConfigEntryKindName]structs.ConfigEntry,
) (uint64, *structs.ServiceSplitterConfigEntry, error) {
idx, entry, err := s.configEntryWithOverridesTxn(tx, ws, structs.ServiceSplitter, serviceName, overrides)
if err != nil {
return 0, nil, err
} else if entry == nil {
return idx, nil, nil
}
splitter, ok := entry.(*structs.ServiceSplitterConfigEntry)
if !ok {
return 0, nil, fmt.Errorf("invalid service config type %T", entry)
}
return idx, splitter, nil
}
// getResolverConfigEntryTxn is a convenience method for fetching a
// service-resolver kind of config entry.
//
// If an override is returned the index returned will be 0.
func (s *Store) getResolverConfigEntryTxn(
tx *memdb.Txn,
ws memdb.WatchSet,
serviceName string,
overrides map[structs.ConfigEntryKindName]structs.ConfigEntry,
) (uint64, *structs.ServiceResolverConfigEntry, error) {
idx, entry, err := s.configEntryWithOverridesTxn(tx, ws, structs.ServiceResolver, serviceName, overrides)
if err != nil {
return 0, nil, err
} else if entry == nil {
return idx, nil, nil
}
resolver, ok := entry.(*structs.ServiceResolverConfigEntry)
if !ok {
return 0, nil, fmt.Errorf("invalid service config type %T", entry)
}
return idx, resolver, nil
}
func (s *Store) configEntryWithOverridesTxn(
tx *memdb.Txn,
ws memdb.WatchSet,
kind string,
name string,
overrides map[structs.ConfigEntryKindName]structs.ConfigEntry,
) (uint64, structs.ConfigEntry, error) {
if len(overrides) > 0 {
entry, ok := overrides[structs.ConfigEntryKindName{
Kind: kind, Name: name,
}]
if ok {
return 0, entry, nil // a nil entry implies it should act like it is erased
}
}
return s.configEntryTxn(tx, ws, kind, name)
}