A nodejs logger for AWS Lambda
- Writes logs to stdout using console.log
- Logs in JSON format
- Supports log levels: DEBUG, INFO, WARN, ERROR and OFF
- Defaults to log level INFO
- Support for pretty print when debugging
- Built using typescript and includes types
Basic example:
import { APIGatewayEvent } from 'aws-lambda';
import { log } from 'pn-lambda-logger';
import { ok } from '../aws/response';
export const healthCheck = async (event: APIGatewayEvent, context: AWSLambda.Context, cb: AWSLambda.Callback) => {
log.info('My message');
}
{
"@timestamp": 1541421856289,
"level": "INFO",
"message": "My message"
}
Context and meta data
import { APIGatewayEvent } from 'aws-lambda';
import { log } from 'pn-lambda-logger';
import { ok } from '../aws/response';
export const healthCheck = async (event: APIGatewayEvent, context: AWSLambda.Context, cb: AWSLambda.Callback) => {
log.setup({ context, host: event.headers['Host'], verb: event.httpMethod, useragent: event.headers['User-Agent'], query: event.queryStringParameters, path: event.path, xRequestId: event.headers['X-Request-ID'] });
log.info({ message: 'Message' });
cb(null, ok({ status: 'UP' }));
};
{
"@timestamp": 1541460988579,
"level": "INFO",
"message": "Message",
"host": "abc123.execute-api.eu-west-1.amazonaws.com",
"verb": "GET",
"path": "/manage/health",
"useragent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.77 Safari/537.36",
"query": {
"hello": "world"
},
"awsRequestId": "asdas-adsas-asdasdas-asdasda-adss",
"functionName": "hello",
"invokedFunctionArn": "arn:cccccc",
"memoryLimitInMB": 1024,
"remainingTime": 11147
}
Log Levels
The default log level is INFO log.level = LogLevels.INFO;
.
To show debug messages you need to explicitly set the log.level to DEBUG like this:
log.level = LogLevels.DEBUG;
log.debug({ message: 'message' });
{
"@timestamp": 1541421856291,
"level": "DEBUG",
"message": "Message",
}
You can add any number of extra properties to the object when logging, like this:
log.setup({ context, host: event.headers['Host'], verb: event.httpMethod, useragent: event.headers['User-Agent'], query: event.queryStringParameters, path: event.path, xRequestId: event.headers['X-REQUEST-ID'] });
log.info({ message: 'Message', myProp: 'hello', myNestedProp: {subProp: 'something'} });
{
"@timestamp": 1541429192677,
"level": "INFO",
"message": "Message",
"host": "abc123.execute-api.eu-west-1.amazonaws.com",
"verb": "GET",
"path": "/manage/health",
"useragent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.77 Safari/537.36",
"query": {
"hello": "world"
},
"awsRequestId": "a3de505e-f16b-42f4-b3e6-bcd2e4a73903",
"functionName": "ExampleCloudFormationStackName-ExampleLambdaFunctionResourceName-AULC3LB8Q02F",
"functionVersion": "$LATEST",
"invokedFunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:ExampleCloudFormationStackName-ExampleLambdaFunctionResourceName-AULC3LB8Q02F",
"memoryLimitInMB": 128,
"remainingTime": 3,
"myProp": "hello",
"myNestedProp": {
"subProp": "something"
}
}
Pretty print
You can improve the appearance of logs when debugging, to make them easier to read. This will also add color to your logs
if your terminal supports it.
To use, set the PN_LOG_PRETTY
environment variable.
export PN_LOG_PRETTY=true
Mute all logs:
log.level = LogLevels.OFF;
Set log level with environment variable
You can easily set the initial log level by setting the environment variable PN_LOG_LEVEL
. This can be useful for setting different log levels in different environments TEST|PROD etc. Use 'OFF', 'DEBUG', 'INFO', 'WARN' or 'ERROR', like this:
PN_LOG_LEVEL: 'DEBUG'
Release process
When you are ready to release a version, take the following steps.
-
Bump the version
in package.json
according to semver. If we are making a
non-breaking change, compared to the last version, the new version
would be 0.12.0
.
"version": "0.11.0"
to "version": "0.12.0"
-
Make a commit titled "Release version
":
git add package.json
git commit -m "Release 0.12.0"
-
Tag your commit with the version
, this is what triggers the deployment in Bitbucket Pipelines.
The tagged commit must start with release-
git tag -a "release-0.12.0" -m "Release 0.12.0"
-
Push to master!
git push --follow-tags