InstallationLearn how to integrate LambdaLog into your project.

To get started, install LambdaLog using NPM or Yarn to your project:

NPM:

1npm install lambda-log

Yarn:

1yarn add lambda-log

Usage

In the most simplest form:

1const log = require('lambda-log');
2 
3log.info('Hello from LambdaLog!');

or for a more in-depth example in a Lambda Function:

 1const log = require('lambda-log');
 2 
 3exports.handler = function(event, context, callback) {
 4    // set some optional metadata to be included in all logs (this is an overkill example)
 5    log.options.meta.event = event;
 6    // add additional tags to all logs
 7    log.options.tags.push(event.env);
 8 
 9    // Log info message
10    log.info('my lambda function is running!');
11    //=> { _logLevel: 'info' msg: 'my lambda function is running!', event:..., _tags: ['log', 'info', ...] }
12 
13    if(somethingHappenedButNotFatal) {
14        log.warn('something is missing, but it is OK');
15        //=> { _logLevel: 'warn', msg: 'something is missing, but it is OK', event:..., _tags: ['log', 'warn', ...] }
16    }
17 
18    // Debug messages are not generated or displayed unless enabled in the config
19    log.debug('some debug message');
20    //=> false
21 
22    // Enable debug messages
23    log.options.debug = true;
24    log.debug('some debug message again');
25    //=> { _logLevel: 'debug', msg: 'some debug message again', event:..., _tags: ['log', 'debug', ...] }
26 
27    someAsyncTask(function(err, results) {
28        if(err) {
29            log.error(err);
30            //=> { _logLevel: 'error', msg: 'Error from someAsyncTask', stack: ..., event: ..., _tags: ['log', 'error', ...]}
31        } else {
32            log.info('someAsyncTask completed successfully!', { results });
33            //=> { _logLevel: 'info', msg: 'someAsyncTask completed successfully!', results:..., event: ..., _tags: ['log', 'info', ...]}
34        }
35    });
36 
37    // New in version 1.4.0 - assert
38    someAsyncTask(function(err, results) {
39        if(err) {
40            log.error(err);
41            //=> { _logLevel: 'error', msg: 'Error from someAsyncTask', stack: ..., event: ..., _tags: ['log', 'error', ...]}
42        } else {
43            // Will only log if no results are returned
44            log.assert(results, 'No results returned from someAsyncTask');
45        }
46    });
47};

Check out the API Reference for more examples.