otel logger extension

Author: Ankcorn

README.md

@@ -29,6 +29,29 @@ For production systems you should remove the latency overhead of sending open te
 `arn:aws:lambda:${region}:097948374213:layer:baselime-extension-${'x86_64' || 'arm64'}:1`
 ```
 
+## Adding Custom Events
+
+Our simple but powerful OTEL compatible logging extension lets you add context rich events to your traces. These events can be useful to show more detailed context on errors, add steps that you want recorded for a business process or simply add extra debug information.
+
+```javascript
+const { logger } = require("@baselime/lambda-node-opentelemetry");
+
+logger.info("This is an informational message", {
+  operation: "copy-paste-replace",
+  count: 9000,
+});
+```
+
+The extension provides an object that includes four logging functions - info, warn, debug, and error - enabling you to log messages with varying levels of severity. By setting the LOG_LEVEL environment variable, you can control the visibility of the logs.
+
+```javascript
+const { logger } = require("@baselime/lambda-node-opentelemetry");
+
+logger.info("This is an informational message", { payload: { foo: "bar" } });
+logger.warn("This is a warning message", { payload: { foo: "bar" } });
+logger.debug("This is a debug message", { payload: { foo: "bar" } });
+logger.error("This is an error message", { payload: { foo: "bar" } });
+```
 ## Manual Installation
 
 Install the `@baselime/lambda-node-opentelemetry` package

examples/sst/stacks/MyStack.ts

@@ -1,5 +1,6 @@
 import { StackContext, Api, EventBus, App } from "sst/constructs";
 import { LayerVersion } from "aws-cdk-lib/aws-lambda";
+import { Tags } from "aws-cdk-lib";
 
 
 function magicShit(api) {
@@ -10,7 +11,7 @@ export function API({ stack }: StackContext) {
   const baselime = LayerVersion.fromLayerVersionArn(
     stack,
     "BaselimeLayer",
-    `arn:aws:lambda:eu-west-2:374211872663:layer:baselime-node:7`
+    `arn:aws:lambda:eu-west-2:374211872663:layer:baselime-node:8`
   );
 
   if (!(stack.node.scope as App)?.local) {
@@ -19,8 +20,9 @@ export function API({ stack }: StackContext) {
       AWS_LAMBDA_EXEC_WRAPPER: '/opt/baselime',
       BASELIME_KEY: process.env.BASELIME_KEY as string,
       COLLECTOR_URL: 'https://otel.baselime.cc/v1',
-      OTEL_LOG_LEVEL: 'debug',
-      BASELIME_ORIGINAL_HANDLER: 'packages/functions/src/todo.handler',
+     
+      BASELIME_ACTUAL_HANDLER: 'packages/functions/src/todo.handler',
+      
     });
 
   }
@@ -48,7 +50,7 @@ export function API({ stack }: StackContext) {
     },
   });
 
-  magicShit(api);
+  Tags.of(api).add("baselime:tracing", "true");
 
   bus.subscribe("todo.created", {
     handler: "packages/functions/src/events/todo-created.handler",

handler.cjs

@@ -1,4 +1,4 @@
-const { loadSync } = require('../src/loader');
+const { loadSync } = require('./loader');
 
 exports.handler = function (...args) {
 

handler.mjs

@@ -1,5 +1,5 @@
-import { load } from '../src/loader.js';
-import { wrap } from '../src/index.js';
+import { load } from './loader.js';
+import { wrap } from './index.js';
 
 export const handler = async function (...args) {
     const actualHandler = process.env.BASELIME_ACTUAL_HANDLER;

handlers/handler.cjs

@@ -1,4 +1,4 @@
-const { loadSync } = require('../src/loader');
+const { loadSync } = require('./loader');
 
 exports.handler = function (...args) {
 

handlers/handler.mjs

@@ -1,5 +1,5 @@
-import { load } from '../src/loader.js';
-import { wrap } from '../src/index.js';
+import { load } from './loader.js';
+import { wrap } from './index.js';
 
 export const handler = async function (...args) {
     const actualHandler = process.env.BASELIME_ACTUAL_HANDLER;

src/index.ts

@@ -2,13 +2,13 @@ import api, { trace, context, propagation, Context as OtelContext, ROOT_CONTEXT,
 import { Handler } from "aws-lambda";
 import { flattenObject } from './utils';
 import { Context } from 'aws-lambda';
+export * as logger from './logger';
 
 declare const global : {
 	baselimeLambdaFlush: () => void;
 }
 
 export function wrap(handler: Handler) {
-
   return async (event: any, lambda_context: Context) => {
     const tracer = trace.getTracer('@baselime/baselime-lambda-wrapper', '1');
 
@@ -117,4 +117,5 @@ function extractContext(event: any) {
       );
   }
   return propagation.extract(api.context.active(), {}, headerGetter);
-}
+}
+

src/logger.ts

@@ -0,0 +1,56 @@
+import { trace, context } from '@opentelemetry/api';
+import { flattenObject } from 'utils';
+const levels = ['debug', 'info', 'warn', 'error', 'fatal'];
+
+function _log(level: string, message: string, data: Record<string, unknown>) {
+    if (!_isLogged(level)) return;
+    if (!levels.includes(level)) {
+        throw new Error(`Invalid log level ${level}`);
+    }
+
+    const span = trace.getSpan(context.active());
+    span?.addEvent(message, flattenObject(data));
+}
+
+const LOG_LEVEL = process.env.LOG_LEVEL || "INFO";
+
+function _isLogged(level: string) {
+    if (level === "baselime") {
+        return true;
+    }
+    const levels = ["DEBUG", "INFO", "WARN", "ERROR"];
+
+    return levels.indexOf(level.toUpperCase()) >= levels.indexOf(LOG_LEVEL);
+}
+
+
+function getErrorData(data: Record<string, unknown>, err: Error): Record<string, unknown> {
+    if (!err) {
+        return data;
+    }
+
+    return {
+        ...(data || {}),
+        error: {
+            name: err.name,
+            message: err.message,
+            stack: err.stack,
+        },
+    };
+}
+
+export function info(message: string, data?: Record<string, unknown>) {
+    _log('info', message, data || {});
+}
+
+export function debug(message: string, data?: Record<string, unknown>) {
+    _log('warn', message, data || {});
+}
+
+export function warn(message: string, data?: Record<string, unknown>, err?: Error) {
+    _log('warn', message, getErrorData(data || {}, err || new Error(message)));
+}
+
+export function error(message: string, data?: Record<string, unknown>, err?: Error) {
+    _log('error', message, getErrorData(data || {}, err || new Error(message)));
+}

src/utils.ts

@@ -3,7 +3,7 @@
  * @param ob Object                 The object to flatten
  * @param prefix String (Optional)  The prefix to add before each key, also used for recursion
  **/
-export function flattenObject(ob: Record<string, unknown>, prefix = "", result: Record<string, unknown> = {}) {
+export function flattenObject(ob: Record<string, unknown>, prefix = "", result: Record<string, unknown> = {}): Record<string, string | number | boolean> {
     // Preserve empty objects and arrays, they are lost otherwise
     if (
       prefix &&