libpod: add hidden env to set sqlite timeout

Some users want to experiment with different timeout values.

Fixes #23236

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

libpod/sqlite_state.go

@@ -39,17 +39,13 @@ const (
 	sqliteOptionForeignKeys = "&_foreign_keys=1"
 	// Make sure that transactions happen exclusively.
 	sqliteOptionTXLock = "&_txlock=exclusive"
-	// Make sure busy timeout is set to high value to keep retrying when the db is locked.
-	// Timeout is in ms, so set it to 100s to have enough time to retry the operations.
-	sqliteOptionBusyTimeout = "&_busy_timeout=100000"
 
 	// Assembled sqlite options used when opening the database.
 	sqliteOptions = "db.sql?" +
 		sqliteOptionLocation +
 		sqliteOptionSynchronous +
 		sqliteOptionForeignKeys +
-		sqliteOptionTXLock +
+		sqliteOptionTXLock
-		sqliteOptionBusyTimeout
 )
 
 // NewSqliteState creates a new SQLite-backed state database.
@@ -71,7 +67,18 @@ func NewSqliteState(runtime *Runtime) (_ State, defErr error) {
 		return nil, fmt.Errorf("creating root directory: %w", err)
 	}
 
-	conn, err := sql.Open("sqlite3", filepath.Join(basePath, sqliteOptions))
+	// Make sure busy timeout is set to high value to keep retrying when the db is locked.
+	// Timeout is in ms, so set it to 100s to have enough time to retry the operations.
+	// Some users might want to experiment with different timeout values (#23236)
+	// DO NOT DOCUMENT or recommend PODMAN_SQLITE_BUSY_TIMEOUT outside of testing.
+	busyTimeout := "100000"
+	if env, ok := os.LookupEnv("PODMAN_SQLITE_BUSY_TIMEOUT"); ok {
+		logrus.Debugf("PODMAN_SQLITE_BUSY_TIMEOUT is set to %s", env)
+		busyTimeout = env
+	}
+	sqliteOptionBusyTimeout := "&_busy_timeout=" + busyTimeout
+
+	conn, err := sql.Open("sqlite3", filepath.Join(basePath, sqliteOptions+sqliteOptionBusyTimeout))
 	if err != nil {
 		return nil, fmt.Errorf("initializing sqlite database: %w", err)
 	}