Merge branch 'feat/version' into 'main'

feat: upgrade command support update db version and exec migration

See merge request opensource/answer!74

cmd/answer/command.go

@@ -4,7 +4,9 @@ import (
 	"fmt"
 	"os"
 
+	"github.com/segmentfault/answer/internal/base/data"
 	"github.com/segmentfault/answer/internal/cli"
+	"github.com/segmentfault/answer/internal/migrations"
 	"github.com/spf13/cobra"
 )
 
@@ -81,7 +83,22 @@ To run answer, use:
 		Short: "upgrade Answer version",
 		Long:  `upgrade Answer version`,
 		Run: func(cmd *cobra.Command, args []string) {
-			fmt.Println("The current app version is 1.0.0, the latest version is 1.0.0, no need to upgrade.")
+			c, err := readConfig()
+			if err != nil {
+				fmt.Println("read config failed: ", err.Error())
+				return
+			}
+			fmt.Println("read config successfully")
+			db, err := data.NewDB(false, c.Data.Database)
+			if err != nil {
+				fmt.Println("new database failed: ", err.Error())
+				return
+			}
+			if err = migrations.Migrate(db); err != nil {
+				fmt.Println("migrate failed: ", err.Error())
+				return
+			}
+			fmt.Println("upgrade done")
 		},
 	}
 

internal/migrations/migrations.go

@@ -0,0 +1,108 @@
+package migrations
+
+import (
+	"fmt"
+
+	"github.com/segmentfault/pacman/log"
+	"xorm.io/xorm"
+)
+
+const minDBVersion = 0 // answer 1.0.0
+
+// Migration describes on migration from lower version to high version
+type Migration interface {
+	Description() string
+	Migrate(*xorm.Engine) error
+}
+
+type migration struct {
+	description string
+	migrate     func(*xorm.Engine) error
+}
+
+// Description returns the migration's description
+func (m *migration) Description() string {
+	return m.description
+}
+
+// Migrate executes the migration
+func (m *migration) Migrate(x *xorm.Engine) error {
+	return m.migrate(x)
+}
+
+// NewMigration creates a new migration
+func NewMigration(desc string, fn func(*xorm.Engine) error) Migration {
+	return &migration{description: desc, migrate: fn}
+}
+
+// Version version
+type Version struct {
+	ID            int   `xorm:"not null pk autoincr comment('id') INT(11) id"`
+	VersionNumber int64 `xorm:"not null default 0 comment('version_number') INT(11) version_number"`
+}
+
+// TableName config table name
+func (Version) TableName() string {
+	return "version"
+}
+
+// Use noopMigration when there is a migration that has been no-oped
+var noopMigration = func(_ *xorm.Engine) error { return nil }
+
+var migrations = []Migration{
+	// 0->1
+	NewMigration("this is first version, no operation", noopMigration),
+}
+
+// GetCurrentDBVersion returns the current db version
+func GetCurrentDBVersion(engine *xorm.Engine) (int64, error) {
+	if err := engine.Sync(new(Version)); err != nil {
+		return -1, fmt.Errorf("sync version failed: %v", err)
+	}
+
+	currentVersion := &Version{ID: 1}
+	has, err := engine.Get(currentVersion)
+	if err != nil {
+		return -1, fmt.Errorf("get first version failed: %v", err)
+	}
+	if !has {
+		_, err := engine.InsertOne(&Version{ID: 1, VersionNumber: 0})
+		if err != nil {
+			return -1, fmt.Errorf("insert first version failed: %v", err)
+		}
+		return 0, nil
+	}
+	return currentVersion.VersionNumber, nil
+}
+
+// ExpectedVersion returns the expected db version
+func ExpectedVersion() int64 {
+	return int64(minDBVersion + len(migrations))
+}
+
+// Migrate database to current version
+func Migrate(engine *xorm.Engine) error {
+	currentDBVersion, err := GetCurrentDBVersion(engine)
+	if err != nil {
+		return err
+	}
+	expectedVersion := ExpectedVersion()
+
+	for currentDBVersion < expectedVersion {
+		log.Infof("[migrate] current db version is %d, try to migrate version %d, latest version is %d",
+			currentDBVersion, currentDBVersion+1, expectedVersion)
+		migrationFunc := migrations[currentDBVersion]
+		log.Infof("[migrate] try to migrate db version %d, description: %s", currentDBVersion+1, migrationFunc.Description())
+		if err := migrationFunc.Migrate(engine); err != nil {
+			log.Errorf("[migrate] migrate to db version %d failed: ", currentDBVersion+1, err.Error())
+			return err
+		}
+		log.Infof("[migrate] migrate to db version %d success", currentDBVersion+1)
+		if _, err := engine.Update(&Version{ID: 1, VersionNumber: currentDBVersion + 1}); err != nil {
+			log.Errorf("[migrate] migrate to db version %d, update failed: %s", currentDBVersion+1, err.Error())
+			return err
+		}
+		currentDBVersion++
+	}
+	return nil
+}