Implement first-pass load reduction controls

packages/observability/src/logger.ts

@@ -22,20 +22,46 @@ export type LoggerOptions = {
   service: string;
   now?: () => string;
   sink?: (record: LogRecord) => void;
+  level?: LogLevel;
 };
 
 const defaultSink = (record: LogRecord) => {
   console.log(JSON.stringify(record));
 };
 
+const LOG_LEVEL_ORDER: Record<LogLevel, number> = {
+  debug: 10,
+  info: 20,
+  warn: 30,
+  error: 40
+};
+
+const resolveLogLevel = (value: string | undefined): LogLevel => {
+  switch ((value ?? "").trim().toLowerCase()) {
+    case "debug":
+    case "info":
+    case "warn":
+    case "error":
+      return value!.trim().toLowerCase() as LogLevel;
+    default:
+      return "info";
+  }
+};
+
 export const createLogger = ({
   service,
   now = () => new Date().toISOString(),
-  sink = defaultSink
+  sink = defaultSink,
+  level = resolveLogLevel(process.env.LOG_LEVEL)
 }: LoggerOptions): Logger => {
-  const write = (level: LogLevel, msg: string, context?: LogContext) => {
+  const levelThreshold = resolveLogLevel(level);
+
+  const write = (recordLevel: LogLevel, msg: string, context?: LogContext) => {
+    if (LOG_LEVEL_ORDER[recordLevel] < LOG_LEVEL_ORDER[levelThreshold]) {
+      return;
+    }
     const record: LogRecord = {
-      level,
+      level: recordLevel,
       service,
       msg,
       ts: now(),