Setup and migration UI refactor (#1190)

* Make config instance-based
* Remove config dependency in paths
* Refactor config init
* Allow startup without database
* Get system status at UI initialise
* Add setup wizard
* Cache and Metadata optional. Database mandatory
* Handle metadata not set during full import/export
* Add links
* Remove config check middleware
* Stash not mandatory
* Panic on missing mandatory config fields
* Redirect setup to main page if setup not required
* Add migration UI
* Remove unused stuff
* Move UI initialisation into App
* Don't create metadata paths on RefreshConfig
* Add folder selector for generated in setup
* Env variable to set and create config file.
Make docker images use a fixed config file.
* Set config file during setup

pkg/database/database.go

@@ -26,8 +26,27 @@ var dbPath string
 var appSchemaVersion uint = 20
 var databaseSchemaVersion uint
 
+var (
+	// ErrMigrationNeeded indicates that a database migration is needed
+	// before the database can be initialized
+	ErrMigrationNeeded = errors.New("database migration required")
+
+	// ErrDatabaseNotInitialized indicates that the database is not
+	// initialized, usually due to an incomplete configuration.
+	ErrDatabaseNotInitialized = errors.New("database not initialized")
+)
+
 const sqlite3Driver = "sqlite3ex"
 
+// Ready returns an error if the database is not ready to begin transactions.
+func Ready() error {
+	if DB == nil {
+		return ErrDatabaseNotInitialized
+	}
+
+	return nil
+}
+
 func init() {
 	// register custom driver with regexp function
 	registerCustomDriver()
@@ -37,20 +56,20 @@ func init() {
 // performs a full migration to the latest schema version. Otherwise, any
 // necessary migrations must be run separately using RunMigrations.
 // Returns true if the database is new.
-func Initialize(databasePath string) bool {
+func Initialize(databasePath string) error {
 	dbPath = databasePath
 
 	if err := getDatabaseSchemaVersion(); err != nil {
-		panic(err)
+		return fmt.Errorf("error getting database schema version: %s", err.Error())
 	}
 
 	if databaseSchemaVersion == 0 {
 		// new database, just run the migrations
 		if err := RunMigrations(); err != nil {
-			panic(err)
+			return fmt.Errorf("error running initial schema migrations: %s", err.Error())
 		}
 		// RunMigrations calls Initialise. Just return
-		return true
+		return nil
 	} else {
 		if databaseSchemaVersion > appSchemaVersion {
 			panic(fmt.Sprintf("Database schema version %d is incompatible with required schema version %d", databaseSchemaVersion, appSchemaVersion))
@@ -59,7 +78,7 @@ func Initialize(databasePath string) bool {
 		// if migration is needed, then don't open the connection
 		if NeedsMigration() {
 			logger.Warnf("Database schema version %d does not match required schema version %d.", databaseSchemaVersion, appSchemaVersion)
-			return false
+			return nil
 		}
 	}
 
@@ -67,7 +86,7 @@ func Initialize(databasePath string) bool {
 	DB = open(databasePath, disableForeignKeys)
 	WriteMu = &sync.Mutex{}
 
-	return false
+	return nil
 }
 
 func open(databasePath string, disableForeignKeys bool) *sqlx.DB {
@@ -150,6 +169,10 @@ func AppSchemaVersion() uint {
 	return appSchemaVersion
 }
 
+func DatabasePath() string {
+	return dbPath
+}
+
 func DatabaseBackupPath() string {
 	return fmt.Sprintf("%s.%d.%s", dbPath, databaseSchemaVersion, time.Now().Format("20060102_150405"))
 }