[MM-41576] Revamp database schema version (#19586)

* revamp db version and add applied migrations endpoint

* replace old schema version with new

* add db version subcommand

* add to local api

* reflect review comments

* log errors

* remove setting the version from model.CurrentVersion

* fix a test

cmd/mattermost/commands/db.go

@@ -5,6 +5,7 @@ package commands
 
 import (
 	"fmt"
+	"strconv"
 
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
@@ -51,13 +52,21 @@ var MigrateCmd = &cobra.Command{
 	RunE:  migrateCmdF,
 }
 
+var DBVersionCmd = &cobra.Command{
+	Use:   "version",
+	Short: "Returns the recent applied version number",
+	RunE:  dbVersionCmdF,
+}
+
 func init() {
 	ResetCmd.Flags().Bool("confirm", false, "Confirm you really want to delete everything and a DB backup has been performed.")
+	DBVersionCmd.Flags().Bool("all", false, "Returns all applied migrations")
 
 	DbCmd.AddCommand(
 		InitDbCmd,
 		ResetCmd,
 		MigrateCmd,
+		DBVersionCmd,
 	)
 
 	RootCmd.AddCommand(
@@ -137,3 +146,35 @@ func migrateCmdF(command *cobra.Command, args []string) error {
 
 	return nil
 }
+
+func dbVersionCmdF(command *cobra.Command, args []string) error {
+	cfgDSN := getConfigDSN(command, config.GetEnvironment())
+	cfgStore, err := config.NewStoreFromDSN(cfgDSN, true, nil, true)
+	if err != nil {
+		return errors.Wrap(err, "failed to load configuration")
+	}
+	config := cfgStore.Get()
+
+	store := sqlstore.New(config.SqlSettings, nil)
+	defer store.Close()
+
+	allFlag, _ := command.Flags().GetBool("all")
+	if allFlag {
+		applied, err2 := store.GetAppliedMigrations()
+		if err2 != nil {
+			return errors.Wrap(err2, "failed to get applied migrations")
+		}
+		for _, migration := range applied {
+			CommandPrettyPrintln(fmt.Sprintf("Varsion: %d, Name: %s", migration.Version, migration.Name))
+		}
+		return nil
+	}
+
+	v, err := store.GetDBSchemaVersion()
+	if err != nil {
+		return errors.Wrap(err, "failed to get schema version")
+	}
+	CommandPrettyPrintln("Current database schema version is: " + strconv.Itoa(v))
+
+	return nil
+}