Runtime

lakta.NewRuntime() is the entry point for every Lakta service. It wires modules together and manages their full lifecycle.

Creating a runtime

if err := lakta.NewRuntime(module1, module2, module3, ...).Run(); err != nil {
    os.Exit(1)
}

Run installs signal handlers for SIGTERM/SIGINT, then delegates to RunContext. Pass your own context to RunContext directly if you need custom cancellation.

What the runtime does

1. Dependency sort — topologically sorts all modules from their Provider/Dependent declarations. Returns an error immediately if a required dependency has no provider or a cycle is detected.
2. Init — calls LoadConfig then Init on each module sequentially in resolved order.
3. Logger injection — retrieves *slog.Logger from DI and injects it into context. Wires hot-reload callbacks for HotReloadable modules.
4. StartAsync — all AsyncModule implementations start concurrently and must return quickly.
5. Start — all SyncModule implementations start concurrently and block until shutdown.
6. Shutdown — on signal or any start error, calls Shutdown on all initialized modules in reverse init order with a 30-second deadline.

Module ordering

You do not need to pass modules in dependency order. The runtime resolves order automatically from Provider and Dependent declarations:

// These can be in any order — the runtime sorts them
lakta.NewRuntime(
    myapp.NewModule(),       // declares dependency on *pgxpool.Pool, *slog.Logger
    pgx.NewModule(...),      // declares it provides *pgxpool.Pool
    slog.NewModule(),        // declares it provides *slog.Logger
    config.NewModule(...),   // declares it provides *koanf.Koanf
    tint.NewModule(),        // no deps declared — sorted by original position
)

Modules that implement neither Provider nor Dependent are queued in their original relative order.

Error handling

Situation	Behaviour
Required dep has no provider	Error before any Init fires
Dependency cycle detected	Error before any Init fires
Init returns error	Remaining modules not started; already-initialized modules shut down in reverse order
StartAsync returns error	Shutdown triggered for all initialized modules
Start returns error	Shutdown triggered for all initialized modules
Shutdown returns error	Logged; shutdown continues; first error returned to caller

Signal handling

Run handles SIGTERM and SIGINT. A second signal forces immediate exit without waiting for graceful shutdown.