feat(logger): add support for AWS_LAMBDA_LOG_LEVEL and POWERTOOLS_LOG_LEVEL (#1795)

* feat(logger): support advanced logging

* docs(logger): add alc info

* feat(logger): support alc

* docs: fix alc docs links

* tests(logger): add unit tests for the feature

* docs(logger): make POWERTOOLS_LOG_LEVEL default

Author: dreamorosi

Diff for: docs/core/logger.md

@@ -45,11 +45,11 @@ The library has three optional settings, which can be set via environment variab
 
 These settings will be used across all logs emitted:
 
-| Setting                | Description                                                                                                      | Environment variable            | Default Value       | Allowed Values                                         | Example Value       | Constructor parameter |
-| ---------------------- | ---------------------------------------------------------------------------------------------------------------- | ------------------------------- | ------------------- | ------------------------------------------------------ | ------------------- | --------------------- |
-| **Service name**       | Sets the name of service of which the Lambda function is part of, that will be present across all log statements | `POWERTOOLS_SERVICE_NAME`       | `service_undefined` | Any string                                             | `serverlessAirline` | `serviceName`         |
-| **Logging level**      | Sets how verbose Logger should be, from the most verbose to the least verbose (no logs)                          | `POWERTOOLS_LOG_LEVEL`          | `INFO`              | `DEBUG`, `INFO`, `WARN`, `ERROR`, `CRITICAL`, `SILENT` | `ERROR`             | `logLevel`            |
-| **Sample rate**        | Probability that a Lambda invocation will print all the log items regardless of the log level setting           | `POWERTOOLS_LOGGER_SAMPLE_RATE` | `0`                 | `0.0` to `1.0`                                         | `0.1`               | `sampleRateValue`     |
+| Setting           | Description                                                                                                      | Environment variable            | Default Value       | Allowed Values                                         | Example Value       | Constructor parameter |
+| ----------------- | ---------------------------------------------------------------------------------------------------------------- | ------------------------------- | ------------------- | ------------------------------------------------------ | ------------------- | --------------------- |
+| **Service name**  | Sets the name of service of which the Lambda function is part of, that will be present across all log statements | `POWERTOOLS_SERVICE_NAME`       | `service_undefined` | Any string                                             | `serverlessAirline` | `serviceName`         |
+| **Logging level** | Sets how verbose Logger should be, from the most verbose to the least verbose (no logs)                          | `POWERTOOLS_LOG_LEVEL`          | `INFO`              | `DEBUG`, `INFO`, `WARN`, `ERROR`, `CRITICAL`, `SILENT` | `ERROR`             | `logLevel`            |
+| **Sample rate**   | Probability that a Lambda invocation will print all the log items regardless of the log level setting            | `POWERTOOLS_LOGGER_SAMPLE_RATE` | `0`                 | `0.0` to `1.0`                                         | `0.1`               | `sampleRateValue`     |
 
 See all environment variables in the [Environment variables](../index.md/#environment-variables) section.
 Check API docs to learn more about [Logger constructor options](https://docs.powertools.aws.dev/lambda/typescript/latest/api/types/_aws_lambda_powertools_logger.types.ConstructorOptions.html){target="_blank"}.

Diff for: packages/logger/src/Logger.ts

@@ -2,6 +2,7 @@ import { Utility } from '@aws-lambda-powertools/commons';
 import type { HandlerMethodDecorator } from '@aws-lambda-powertools/commons/types';
 import type { Context, Handler } from 'aws-lambda';
 import merge from 'lodash.merge';
+import { format } from 'node:util';
 import { Console } from 'node:console';
 import { format } from 'node:util';
 import { randomInt } from 'node:crypto';

Diff for: packages/logger/tests/unit/Logger.test.ts

@@ -136,7 +136,7 @@ describe('Class: Logger', () => {
       // Prepare
       const loggerOptions = undefined;
       delete process.env.POWERTOOLS_SERVICE_NAME;
-      delete process.env.LOG_LEVEL;
+      delete process.env.POWERTOOLS_LOG_LEVEL;
 
       // Act
       const logger = new Logger(loggerOptions);
@@ -286,7 +286,7 @@ describe('Class: Logger', () => {
     test('when no log level is set, returns a Logger instance with INFO level', () => {
       // Prepare
       const loggerOptions: ConstructorOptions = {};
-      delete process.env.LOG_LEVEL;
+      delete process.env.POWERTOOLS_LOG_LEVEL;
 
       // Act
       const logger = new Logger(loggerOptions);
@@ -354,6 +354,9 @@ describe('Class: Logger', () => {
         get(name: string): string {
           return `a-string-from-${name}`;
         },
+        getAwsLogLevel() {
+          return 'INFO';
+        },
         getCurrentEnvironment(): string {
           return 'dev';
         },