MM-53228: Adding schema version to cluster info (#24209)

With the schema version available, a job can query for
the cluster info to confirm whether or not all nodes
in a cluster are upgraded to the same version or not.

This will help it in determining whether to start
the job or not.

https://mattermost.atlassian.net/browse/MM-53228

```release-note
NONE
```

server/channels/store/sqlstore/store.go

@@ -8,6 +8,7 @@ import (
 	"database/sql"
 	dbsql "database/sql"
 	"fmt"
+	"path"
 	"strconv"
 	"strings"
 	"sync"
@@ -20,10 +21,12 @@ import (
 	_ "github.com/golang-migrate/migrate/v4/source/file"
 	"github.com/jmoiron/sqlx"
 	"github.com/lib/pq"
+	"github.com/mattermost/morph/models"
 	"github.com/pkg/errors"
 
 	"github.com/mattermost/mattermost/server/public/model"
 	"github.com/mattermost/mattermost/server/public/shared/mlog"
+	"github.com/mattermost/mattermost/server/v8/channels/db"
 	"github.com/mattermost/mattermost/server/v8/channels/store"
 	"github.com/mattermost/mattermost/server/v8/einterfaces"
 )
@@ -1289,6 +1292,34 @@ func (ss *SqlStore) toReserveCase(str string) string {
 	return fmt.Sprintf("`%s`", strings.Title(str))
 }
 
+func (ss *SqlStore) GetLocalSchemaVersion() (int, error) {
+	assets := db.Assets()
+
+	assetsList, err := assets.ReadDir(path.Join("migrations", ss.DriverName()))
+	if err != nil {
+		return 0, err
+	}
+
+	maxVersion := 0
+	for _, entry := range assetsList {
+		// parse the version name from the file name
+		m := models.Regex.FindStringSubmatch(entry.Name())
+		if len(m) < 2 {
+			return 0, fmt.Errorf("migration file name incorrectly formed: %s", entry.Name())
+		}
+
+		version, err := strconv.Atoi(m[1])
+		if err != nil {
+			return 0, err
+		}
+		// store the highest version
+		if maxVersion < version {
+			maxVersion = version
+		}
+	}
+	return maxVersion, nil
+}
+
 func (ss *SqlStore) GetDBSchemaVersion() (int, error) {
 	var version int
 	if err := ss.GetMasterX().Get(&version, "SELECT Version FROM db_migrations ORDER BY Version DESC LIMIT 1"); err != nil {

server/channels/store/sqlstore/store_test.go

@@ -889,6 +889,32 @@ func TestGetDBSchemaVersion(t *testing.T) {
 	}
 }
 
+func TestGetLocalSchemaVersion(t *testing.T) {
+	testDrivers := []string{
+		model.DatabaseDriverPostgres,
+		model.DatabaseDriverMysql,
+	}
+
+	for _, d := range testDrivers {
+		driver := d
+		t.Run(driver, func(t *testing.T) {
+			settings, err := makeSqlSettings(driver)
+			if err != nil {
+				t.Skip(err)
+			}
+			store, err := New(*settings, nil)
+			require.NoError(t, err)
+
+			ver, err := store.GetLocalSchemaVersion()
+			require.NoError(t, err)
+
+			dbVer, err := store.GetDBSchemaVersion()
+			require.NoError(t, err)
+			require.Equal(t, ver, dbVer)
+		})
+	}
+}
+
 func TestGetAppliedMigrations(t *testing.T) {
 	testDrivers := []string{
 		model.DatabaseDriverPostgres,

server/channels/store/store.go

@@ -67,6 +67,7 @@ type Store interface {
 	DropAllTables()
 	RecycleDBConnections(d time.Duration)
 	GetDBSchemaVersion() (int, error)
+	GetLocalSchemaVersion() (int, error)
 	GetAppliedMigrations() ([]model.AppliedMigration, error)
 	GetDbVersion(numerical bool) (string, error)
 	// GetInternalMasterDB allows access to the raw master DB

server/channels/store/storetest/mocks/Store.go

@@ -346,6 +346,30 @@ func (_m *Store) GetInternalReplicaDB() *sql.DB {
 	return r0
 }
 
+// GetLocalSchemaVersion provides a mock function with given fields:
+func (_m *Store) GetLocalSchemaVersion() (int, error) {
+	ret := _m.Called()
+
+	var r0 int
+	var r1 error
+	if rf, ok := ret.Get(0).(func() (int, error)); ok {
+		return rf()
+	}
+	if rf, ok := ret.Get(0).(func() int); ok {
+		r0 = rf()
+	} else {
+		r0 = ret.Get(0).(int)
+	}
+
+	if rf, ok := ret.Get(1).(func() error); ok {
+		r1 = rf()
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
 // Group provides a mock function with given fields:
 func (_m *Store) Group() store.GroupStore {
 	ret := _m.Called()

server/channels/store/storetest/store.go

@@ -114,17 +114,18 @@ func (s *Store) PostAcknowledgement() store.PostAcknowledgementStore {
 func (s *Store) PostPersistentNotification() store.PostPersistentNotificationStore {
 	return &s.PostPersistentNotificationStore
 }
-func (s *Store) MarkSystemRanUnitTests()            { /* do nothing */ }
-func (s *Store) Close()                             { /* do nothing */ }
-func (s *Store) LockToMaster()                      { /* do nothing */ }
-func (s *Store) UnlockFromMaster()                  { /* do nothing */ }
-func (s *Store) DropAllTables()                     { /* do nothing */ }
-func (s *Store) GetDbVersion(bool) (string, error)  { return "", nil }
-func (s *Store) GetInternalMasterDB() *sql.DB       { return nil }
-func (s *Store) GetInternalReplicaDB() *sql.DB      { return nil }
-func (s *Store) GetInternalReplicaDBs() []*sql.DB   { return nil }
-func (s *Store) RecycleDBConnections(time.Duration) {}
-func (s *Store) GetDBSchemaVersion() (int, error)   { return 1, nil }
+func (s *Store) MarkSystemRanUnitTests()             { /* do nothing */ }
+func (s *Store) Close()                              { /* do nothing */ }
+func (s *Store) LockToMaster()                       { /* do nothing */ }
+func (s *Store) UnlockFromMaster()                   { /* do nothing */ }
+func (s *Store) DropAllTables()                      { /* do nothing */ }
+func (s *Store) GetDbVersion(bool) (string, error)   { return "", nil }
+func (s *Store) GetInternalMasterDB() *sql.DB        { return nil }
+func (s *Store) GetInternalReplicaDB() *sql.DB       { return nil }
+func (s *Store) GetInternalReplicaDBs() []*sql.DB    { return nil }
+func (s *Store) RecycleDBConnections(time.Duration)  {}
+func (s *Store) GetDBSchemaVersion() (int, error)    { return 1, nil }
+func (s *Store) GetLocalSchemaVersion() (int, error) { return 1, nil }
 func (s *Store) GetAppliedMigrations() ([]model.AppliedMigration, error) {
 	return []model.AppliedMigration{}, nil
 }

server/public/model/cluster_info.go

@@ -4,9 +4,10 @@
 package model
 
 type ClusterInfo struct {
-	Id         string `json:"id"`
-	Version    string `json:"version"`
-	ConfigHash string `json:"config_hash"`
-	IPAddress  string `json:"ipaddress"`
-	Hostname   string `json:"hostname"`
+	Id            string `json:"id"`
+	Version       string `json:"version"`
+	SchemaVersion string `json:"schema_version"`
+	ConfigHash    string `json:"config_hash"`
+	IPAddress     string `json:"ipaddress"`
+	Hostname      string `json:"hostname"`
 }