Add DB migration control logic

documize/api/request/init.go

@@ -1,6 +1,7 @@
 package request
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"strings"
@@ -35,6 +36,10 @@ func (dr *databaseRequest) MakeTx() (err error) {
 
 func init() {
 	var err error
+	var upgrade = "false"
+
+	environment.GetString(&upgrade, "upgrade", false,
+		"to upgrade the database set to 'true' (only this Documize binary must be running)", nil)
 
 	environment.GetString(&connectionString, "db", true,
 		`"username:password@protocol(hostname:port)/databasename" for example "fred:bloggs@tcp(localhost:3306)/documize"`,
@@ -65,6 +70,24 @@ func init() {
 				log.Info("database.Check(Db) !OK, going into setup mode")
 			}
 
+			migrations, err := database.Migrations(ConfigString("DATABASE", "last_migration"))
+			if err != nil {
+				log.Error("Unable to find required database migrations: ", err)
+				os.Exit(2)
+			}
+			if len(migrations) > 0 {
+				if strings.ToLower(upgrade) != "true" {
+					log.Error("database migrations are required",
+						errors.New("the -upgrade flag is not 'true'"))
+					os.Exit(2)
+
+				}
+				if err := migrations.Migrate(); err != nil {
+					log.Error("Unable to run database migration: ", err)
+					os.Exit(2)
+				}
+			}
+
 			return false // value not changed
 		})
 }

documize/database/migrate.go

@@ -1 +1,54 @@
 package database
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+
+	"github.com/documize/community/documize/web"
+)
+
+const migrationsDir = "bindata/scripts/migrate"
+
+// MigrationsT holds a list of migration sql files to run.
+type MigrationsT []string
+
+// Migrations returns a list of the migrations to update the database as required for this version of the code.
+func Migrations(last_migration string) (MigrationsT, error) {
+
+	last_migration = strings.TrimPrefix(strings.TrimSuffix(last_migration, `"`), `"`)
+
+	files, err := web.AssetDir(migrationsDir)
+	if err != nil {
+		return nil, err
+	}
+	sort.Strings(files)
+
+	ret := make(MigrationsT, 0, len(files))
+
+	hadLast := false
+
+	for _, v := range files {
+		if v == last_migration {
+			hadLast = true
+		} else {
+			if hadLast {
+				ret = append(ret, v)
+			}
+		}
+	}
+
+	return ret, nil
+}
+
+// Migrate the database as required.
+func (m MigrationsT) Migrate() error {
+	for _, v := range m {
+		buf, err := web.Asset(migrationsDir + "/" + v)
+		if err != nil {
+			return err
+		}
+		fmt.Println("DEBUG database.Migrate() ", v, ":\n", string(buf)) // TODO actually run the SQL
+	}
+	return nil
+}