[MM-31094] Replication Lag (#16888)

* MM-31094: Adds tooling to develop and test using a MySQL instance with replication lag. Adds some lazy lookups to fallback to master if results are not found.

* MM-31094: Removes mysql-read-replica from default docker services.

* MM-31094: Switches (store..SessionStore).Get and (store.TeamStore).GetMember to using context.Context.

* MM-31094: Updates (store.UsersStore).Get to use context.

* MM-31094: Updates (store.PostStore).Get to use context.

* MM-31094: Removes feature flag and config setting.

* MM-31094: Rolls back some master reads.

* MM-31094: Rolls a non-cache read.

* MM-31094: Removes feature flag from the store.

* MM-31094: Removes unused constant and struct field.

* MM-31094: Removes some old feature flag references.

* MM-31094: Fixes some tests.

* MM-31094: App layers fix.

* MM-31094: Fixes mocks.

* MM-31094: Don't reparse flag.

* MM-31094: No reparse.

* MM-31094: Removed unused FeatureFlags field.

* MM-31094: Removes unnecessary feature flags variable declarations.

* MM-31094: Fixes copy-paste error.

* MM-31094: Fixes logical error.

* MM-30194: Removes test method from store.

* Revert "MM-30194: Removes test method from store."

This reverts commit d5a6e8529bd5f4d993824c828e239d009b05e567.

* MM-31094: Conforming to make's strange syntax.

* MM-31094: Configures helper for read replica with option.

* MM-31094: Adds some missing ctx's.

* MM-31094: WIP

* MM-31094: Updates test names.

* MM-31094: WIP

* MM-31094: Removes unnecessary master reads.

* MM-31094: ID case changes out of scope.

* MM-31094: Removes unused context.

* MM-31094: Switches to a helper. Removes some var naming changes. Fixes a merge error.

* MM-31094: Removes SQLITE db driver ref.

* MM-31094: Layer generate fix.

* MM-31094: Removes unnecessary changes.

* MM-31094: Moves test method.

* MM-31094: Re-add previous fix.

* MM-31094: Removes make command for dev.

* MM-31094: Fix for login.

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

store/sqlstore/store.go

@@ -132,7 +132,7 @@ type SqlStore struct {
 	rrCounter      int64
 	srCounter      int64
 	master         *gorp.DbMap
-	replicas       []*gorp.DbMap
+	Replicas       []*gorp.DbMap
 	searchReplicas []*gorp.DbMap
 	stores         SqlStoreStores
 	settings       *model.SqlSettings
@@ -318,9 +318,9 @@ func (ss *SqlStore) initConnection() {
 	ss.master = setupConnection("master", *ss.settings.DataSource, ss.settings)
 
 	if len(ss.settings.DataSourceReplicas) > 0 {
-		ss.replicas = make([]*gorp.DbMap, len(ss.settings.DataSourceReplicas))
+		ss.Replicas = make([]*gorp.DbMap, len(ss.settings.DataSourceReplicas))
 		for i, replica := range ss.settings.DataSourceReplicas {
-			ss.replicas[i] = setupConnection(fmt.Sprintf("replica-%v", i), replica, ss.settings)
+			ss.Replicas[i] = setupConnection(fmt.Sprintf("replica-%v", i), replica, ss.settings)
 		}
 	}
 
@@ -395,8 +395,8 @@ func (ss *SqlStore) GetReplica() *gorp.DbMap {
 		return ss.GetMaster()
 	}
 
-	rrNum := atomic.AddInt64(&ss.rrCounter, 1) % int64(len(ss.replicas))
-	return ss.replicas[rrNum]
+	rrNum := atomic.AddInt64(&ss.rrCounter, 1) % int64(len(ss.Replicas))
+	return ss.Replicas[rrNum]
 }
 
 func (ss *SqlStore) TotalMasterDbConnections() int {
@@ -409,7 +409,7 @@ func (ss *SqlStore) TotalReadDbConnections() int {
 	}
 
 	count := 0
-	for _, db := range ss.replicas {
+	for _, db := range ss.Replicas {
 		count = count + db.Db.Stats().OpenConnections
 	}
 
@@ -1008,9 +1008,9 @@ func IsUniqueConstraintError(err error, indexName []string) bool {
 }
 
 func (ss *SqlStore) GetAllConns() []*gorp.DbMap {
-	all := make([]*gorp.DbMap, len(ss.replicas)+1)
-	copy(all, ss.replicas)
-	all[len(ss.replicas)] = ss.master
+	all := make([]*gorp.DbMap, len(ss.Replicas)+1)
+	copy(all, ss.Replicas)
+	all[len(ss.Replicas)] = ss.master
 	return all
 }
 
@@ -1033,7 +1033,7 @@ func (ss *SqlStore) RecycleDBConnections(d time.Duration) {
 
 func (ss *SqlStore) Close() {
 	ss.master.Db.Close()
-	for _, replica := range ss.replicas {
+	for _, replica := range ss.Replicas {
 		replica.Db.Close()
 	}
 
@@ -1210,6 +1210,10 @@ func (ss *SqlStore) UpdateLicense(license *model.License) {
 	ss.license = license
 }
 
+func (ss *SqlStore) GetLicense() *model.License {
+	return ss.license
+}
+
 func (ss *SqlStore) migrate(direction migrationDirection) error {
 	var driver database.Driver
 	var err error