Make write-ahead-log default and configurable for sqlite (#1985)

* correctly enable WAL log for sqlite

this commit makes headscale correctly enable write-ahead-log for
sqlite and adds an option to turn it on and off.

WAL is enabled by default and should make sqlite perform a lot better,
even further eliminating the need to use postgres.

It also adds a couple of other useful defaults.

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

* update changelog

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

---------

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>

CHANGELOG.md

@@ -59,6 +59,7 @@ after improving the test harness as part of adopting [#1460](https://github.com/
 - Add `autogroup:internet` to Policy [#1917](https://github.com/juanfont/headscale/pull/1917)
 - Restore foreign keys and add constraints [#1562](https://github.com/juanfont/headscale/pull/1562)
 - Make registration page easier to use on mobile devices
+- Make write-ahead-log default on and configurable for SQLite [#1985](https://github.com/juanfont/headscale/pull/1985)
 
 ## 0.22.3 (2023-05-12)
 

config-example.yaml

@@ -144,6 +144,10 @@ database:
   sqlite:
     path: /var/lib/headscale/db.sqlite
 
+    # Enable WAL mode for SQLite. This is recommended for production environments.
+    # https://www.sqlite.org/wal.html
+    write_ahead_log: true
+
   # # Postgres config
   # postgres:
   #   # If using a Unix socket to connect to Postgres, set the socket path in the 'host' field and leave 'port' blank.

hscontrol/db/db.go

@@ -434,13 +434,29 @@ func openDB(cfg types.DatabaseConfig) (*gorm.DB, error) {
 			Msg("Opening database")
 
 		db, err := gorm.Open(
-			sqlite.Open(cfg.Sqlite.Path+"?_synchronous=1&_journal_mode=WAL"),
+			sqlite.Open(cfg.Sqlite.Path),
 			&gorm.Config{
 				Logger: dbLogger,
 			},
 		)
 
-		db.Exec("PRAGMA foreign_keys=ON")
+		if err := db.Exec(`
+			PRAGMA foreign_keys=ON;
+			PRAGMA busy_timeout=10000;
+			PRAGMA auto_vacuum=INCREMENTAL;
+			PRAGMA synchronous=NORMAL;
+			`).Error; err != nil {
+			return nil, fmt.Errorf("enabling foreign keys: %w", err)
+		}
+
+		if cfg.Sqlite.WriteAheadLog {
+			if err := db.Exec(`
+				PRAGMA journal_mode=WAL;
+				PRAGMA wal_autocheckpoint=0;
+				`).Error; err != nil {
+				return nil, fmt.Errorf("setting WAL mode: %w", err)
+			}
+		}
 
 		// The pure Go SQLite library does not handle locking in
 		// the same way as the C based one and we cant use the gorm

hscontrol/types/config.go

@@ -82,6 +82,7 @@ type Config struct {
 
 type SqliteConfig struct {
 	Path          string
+	WriteAheadLog bool
 }
 
 type PostgresConfig struct {
@@ -222,6 +223,8 @@ func LoadConfig(path string, isFile bool) error {
 	viper.SetDefault("database.postgres.max_idle_conns", 10)
 	viper.SetDefault("database.postgres.conn_max_idle_time_secs", 3600)
 
+	viper.SetDefault("database.sqlite.write_ahead_log", true)
+
 	viper.SetDefault("oidc.scope", []string{oidc.ScopeOpenID, "profile", "email"})
 	viper.SetDefault("oidc.strip_email_domain", true)
 	viper.SetDefault("oidc.only_start_if_oidc_is_available", true)
@@ -443,6 +446,7 @@ func GetDatabaseConfig() DatabaseConfig {
 			Path: util.AbsolutePathFromConfigPath(
 				viper.GetString("database.sqlite.path"),
 			),
+			WriteAheadLog: viper.GetBool("database.sqlite.write_ahead_log"),
 		},
 		Postgres: PostgresConfig{
 			Host:               viper.GetString("database.postgres.host"),