feat(observability): add structured pino logging

packages/observability/package.json

@@ -2,10 +2,16 @@
   "name": "@household/observability",
   "private": true,
   "type": "module",
+  "exports": {
+    ".": "./src/index.ts"
+  },
   "scripts": {
     "build": "bun build src/index.ts --outdir dist --target bun",
     "typecheck": "tsgo --project tsconfig.json --noEmit",
     "test": "bun test --pass-with-no-tests",
     "lint": "oxlint \"src\""
+  },
+  "dependencies": {
+    "pino": "^9.9.0"
   }
 }

packages/observability/src/index.ts

@@ -1 +1,53 @@
-export const observabilityReady = true
+import pino, { type Bindings, type Logger, type LoggerOptions } from 'pino'
+
+export type { Logger }
+
+export type LogLevel = 'debug' | 'info' | 'warn' | 'error'
+
+let rootLogger = pino({
+  level: 'info',
+  timestamp: pino.stdTimeFunctions.isoTime,
+  base: null,
+  formatters: {
+    level(label) {
+      return {
+        level: label
+      }
+    }
+  }
+})
+
+export function configureLogger(
+  options: {
+    level?: LogLevel
+    service?: string
+    base?: Bindings
+  } = {}
+): Logger {
+  const loggerOptions: LoggerOptions = {
+    level: options.level ?? 'info',
+    timestamp: pino.stdTimeFunctions.isoTime,
+    base: null,
+    formatters: {
+      level(label) {
+        return {
+          level: label
+        }
+      }
+    }
+  }
+
+  rootLogger = pino(loggerOptions).child({
+    service: options.service ?? 'household',
+    ...options.base
+  })
+
+  return rootLogger
+}
+
+export function getLogger(name: string, bindings: Bindings = {}): Logger {
+  return rootLogger.child({
+    logger: name,
+    ...bindings
+  })
+}