Logger
LokiLogger — high-level logger with batching, redaction, and auto-flush
The LokiLogger is the recommended entry point for most use cases. It wraps LokiTransport with automatic batching, configurable redaction, and background flushing.
Basic Usage
import { LokiLogger } from "uloki";
const logger = new LokiLogger({
endpoint: "http://localhost:3100",
labels: { service: "worker", env: "production" },
batchSize: 10,
flushInterval: 5000,
});
logger.log({ line: "Job started", labels: { level: "info" } });
logger.log({ line: "Job completed", labels: { level: "info" } });
// Graceful shutdown
await logger.dispose();How Batching Works
Entries are buffered in memory and flushed to Loki when either:
- Batch size is reached (
batchSizeentries buffered) - Flush interval elapses (
flushIntervalms since last flush) flush()is called manuallydispose()is called (stops interval + final flush)
const logger = new LokiLogger({
batchSize: 50, // Flush every 50 entries
flushInterval: 10000, // Or every 10 seconds
});
// Buffered — will flush when 50 entries or 10s passes
for (let i = 0; i < 100; i++) {
logger.log({ line: `Event ${i}` });
}Authentication
Basic auth via username/password or custom headers:
const logger = new LokiLogger({
endpoint: "https://loki.example.com",
username: "admin",
password: "secret",
});
// Or custom headers
const logger = new LokiLogger({
endpoint: "https://loki.example.com",
headers: {
"X-Scope-OrgID": "tenant-1",
},
});Flush Callback
Register a callback for dev introspection:
const logger = new LokiLogger({
endpoint: "http://localhost:3100",
onFlush: (entries) => {
console.log(`Flushed ${entries.length} entries`);
},
});
// Or later
logger.onFlush((entries) => {
console.log(`Flushed ${entries.length} entries`);
});Disabling
When enabled: false, log() is a no-op — no memory allocations, no HTTP calls.
const logger = new LokiLogger({
endpoint: "http://localhost:3100",
enabled: process.env.NODE_ENV !== "test",
});