MM-35030: Hoist GetDBVersion before creating store (#17764)

* MM-35030: Hoist GetDBVersion before creating store

The creation of the store included running the migrations
which means that SQL statements would be executed before
we could make the check for DB version.

We perform the DB check before running the migrations.

https://mattermost.atlassian.net/browse/MM-35030

```release-note
NONE
```

* fix lint error

app/server.go

@@ -20,7 +20,6 @@ import (
 	"os/exec"
 	"path"
 	"runtime"
-	"strconv"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -360,19 +359,6 @@ func NewServer(options ...Option) (*Server, error) {
 	if s.newStore == nil {
 		s.newStore = func() (store.Store, error) {
 			s.sqlStore = sqlstore.New(s.Config().SqlSettings, s.Metrics)
-			if s.sqlStore.DriverName() == model.DATABASE_DRIVER_POSTGRES {
-				ver, err2 := s.sqlStore.GetDbVersion(true)
-				if err2 != nil {
-					return nil, errors.Wrap(err2, "cannot get DB version")
-				}
-				intVer, err2 := strconv.Atoi(ver)
-				if err2 != nil {
-					return nil, errors.Wrap(err2, "cannot parse DB version")
-				}
-				if intVer < sqlstore.MinimumRequiredPostgresVersion {
-					return nil, fmt.Errorf("minimum required postgres version is %s; found %s", sqlstore.VersionString(sqlstore.MinimumRequiredPostgresVersion), sqlstore.VersionString(intVer))
-				}
-			}
 
 			lcl, err2 := localcachelayer.NewLocalCacheLayer(
 				retrylayer.New(s.sqlStore),

store/sqlstore/store.go

@@ -179,6 +179,23 @@ func New(settings model.SqlSettings, metrics einterfaces.MetricsInterface) *SqlS
 
 	store.initConnection()
 
+	if *settings.DriverName == model.DATABASE_DRIVER_POSTGRES {
+		ver, err := store.GetDbVersion(true)
+		if err != nil {
+			mlog.Critical("Cannot get DB version.", mlog.Err(err))
+			os.Exit(ExitGenericFailure)
+		}
+		intVer, err := strconv.Atoi(ver)
+		if err != nil {
+			mlog.Critical("Cannot parse DB version.", mlog.Err(err))
+			os.Exit(ExitGenericFailure)
+		}
+		if intVer < MinimumRequiredPostgresVersion {
+			mlog.Critical("Minimum Postgres version requirements not met.", mlog.String("Found", VersionString(intVer)), mlog.String("Wanted", VersionString(MinimumRequiredPostgresVersion)))
+			os.Exit(ExitGenericFailure)
+		}
+	}
+
 	err := store.migrate(migrationsDirectionUp)
 	if err != nil {
 		mlog.Critical("Failed to apply database migrations.", mlog.Err(err))