SQLite

Read a config or secret value from a local SQLite database, hot-reloaded with fsnotify. Uses the pure-Go modernc.org/sqlite driver (no cgo).

Install

go get github.com/xavidop/mamori/providers/sqlite

import _ "github.com/xavidop/mamori/providers/sqlite"

Using the ref

A sqlite:// ref points at one row of a table in the configured SQLite database file (a key/value lookup), optionally selecting a field from a JSON value. The database file path is provider configuration, not part of the ref.

sqlite://<table>/<key>[#json-field][?key_col=<c>&val_col=<c>]

Examples

• sqlite://settings/greeting - reads value where key = 'greeting' in table settings.
• sqlite://config/db#host - reads the JSON object at key db and returns its host field.
• sqlite://settings/region?key_col=name&val_col=val - reads val where name = 'region' in table settings.

type Config struct {
	Greeting string `source:"sqlite://settings/greeting"`
}

mamori.WithProvider(sqliteprov.New(sqliteprov.WithPath("/var/lib/app/config.db")))

The database file path is not part of the ref (set it with WithPath or SQLITE_PATH), so refs stay portable across environments. The row key is always a bound ? parameter; the table and column names are validated against a strict identifier allowlist (^[A-Za-z_][A-Za-z0-9_]*$) before any query runs, so a ref can never inject SQL. Value.Version is a content hash of the value by default, or a native revision column via WithVersionColumn. Values are non-sensitive unless you set WithSensitive(true) or wrap the field in secret.String.

Error classification

Beyond the not-found case, a query failure that carries a SQLite result code is classified via modernc.org/sqlite’s own *sqlite.Error.Code(), so mamori.ErrorKind can distinguish it:

Codes not listed above report unknown rather than being guessed at, and the original *sqlite.Error stays reachable with errors.As.

Close() releases nothing: this provider opens a fresh *sql.DB on every Resolve and closes it again before returning, so there is never a persistent connection for Close to hold. Its only job is to make the provider terminal, and it does that: after Close, every Resolve reports errors.Is(err, mamori.ErrUnavailable) locally, without opening a connection to the database file. sqlite keeps this terminal-only Close mainly because it sits beside providers/postgres and providers/mysql; a caller sweeping Close across the database providers at shutdown would otherwise be surprised to find sqlite alone still serving.

Watch

Watch uses fsnotify on the database file: when the file changes, mamori re-queries and emits an update. Ideal for a config DB written by another process.

Verified against a real temporary SQLite database (no cgo, no external service). An identifier-allowlist rejection test is included, and error classification is verified both by a table test over real driver errors and by a dedicated Resolve-level test proving the wiring is non-vacuous.