Add GCP logging extender (#503)

* Add GCP logging extender

* Minor version bump for new API

* Update packages/logger/src/logger.ts

Co-Authored-By: kylecarbs <kyle@kwc.io>

packages/logger/src/extender.ts

@@ -0,0 +1,63 @@
+import * as gcl from "@google-cloud/logging";
+import { Extender, logger, field } from "./logger";
+
+export const createStackdriverExtender = (projectId: string, logId: string): Extender => {
+	enum GcpLogSeverity {
+		DEFAULT = 0,
+		DEBUG = 100,
+		INFO = 200,
+		NOTICE = 300,
+		WARNING = 400,
+		ERROR = 500,
+		CRITICAL = 600,
+		ALERT = 700,
+		EMERGENCY = 800,
+	}
+
+	const logging = new gcl.Logging({
+		autoRetry: true,
+		projectId,
+	});
+
+	const log = logging.log(logId);
+	const convertSeverity = (severity: "trace" | "info" | "warn" | "debug" | "error"): GcpLogSeverity => {
+		switch (severity) {
+			case "trace":
+			case "debug":
+				return GcpLogSeverity.DEBUG;
+			case "info":
+				return GcpLogSeverity.INFO;
+			case "error":
+				return GcpLogSeverity.ERROR;
+			case "warn":
+				return GcpLogSeverity.WARNING;
+		}
+	};
+
+	return (options): void => {
+		const severity = convertSeverity(options.type);
+		// tslint:disable-next-line:no-any
+		const metadata = {} as any;
+		if (options.fields) {
+			options.fields.forEach((f) => {
+				if (!f) {
+					return;
+				}
+				metadata[f.identifier] = f.value;
+			});
+		}
+
+		const entry = log.entry({
+			// tslint:disable-next-line:no-any
+			severity: severity as any,
+		}, {
+			...metadata,
+			message: options.message,
+		});
+
+		log.write(entry).catch((ex) => {
+			logger.named("GCP").error("Failed to log", field("error", ex));
+		});
+	};
+
+};