Introduce db migration support

internal/repository/migration.go

@@ -0,0 +1,69 @@
+// Copyright (C) 2022 NHR@FAU, University Erlangen-Nuremberg.
+// All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+package repository
+
+import (
+	"database/sql"
+	"embed"
+	"fmt"
+	"os"
+
+	"github.com/ClusterCockpit/cc-backend/pkg/log"
+	"github.com/golang-migrate/migrate/v4"
+	"github.com/golang-migrate/migrate/v4/database/sqlite3"
+	"github.com/golang-migrate/migrate/v4/source/iofs"
+)
+
+const supportedVersion uint = 2
+
+//go:embed migrations/*.sql
+var migrationFiles embed.FS
+
+func checkDBVersion(db *sql.DB) {
+	driver, err := sqlite3.WithInstance(db, &sqlite3.Config{})
+	if err != nil {
+		log.Fatal(err)
+	}
+	d, err := iofs.New(migrationFiles, "migrations")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	m, err := migrate.NewWithInstance("iofs", d, "sqlite3", driver)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	v, _, err := m.Version()
+	if err != nil {
+		if err == migrate.ErrNilVersion {
+			log.Warn("Legacy database without version or missing database file!")
+		} else {
+			log.Fatal(err)
+		}
+	}
+
+	if v < supportedVersion {
+		log.Warnf("Unsupported database version %d, need %d.\nPlease backup your database file and run cc-backend --migrate-db", v, supportedVersion)
+		os.Exit(0)
+	}
+}
+
+func MigrateDB(db string) {
+	d, err := iofs.New(migrationFiles, "migrations")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	m, err := migrate.NewWithSourceInstance("iofs", d, fmt.Sprintf("sqlite3://%s?_foreign_keys=on", db))
+	if err != nil {
+		log.Fatal(err)
+	}
+	if err := m.Up(); err != nil {
+		log.Fatal(err)
+	}
+
+	m.Close()
+}