CloudWatch Front Logger    

Save your browser console logs to AWS CloudWatch (Inspired by agea/console-cloud-watch)

- Demo: mpyw/cloudwatch-front-logger-demo

Installing

``
npm i cloudwatch-front-logger
`

Preparation

$3

Go to CloudWatch console and create Log Group for this purpose.

$3

Go to IAM Console and create restricted policy for CloudWatch Logs.

- logs:CreateLogStream
- logs:PutLogEvents

`json5
{
"Version": "2019-12-08",
"Statement": [
{
"Sid": "CloudWatchFrontLoggerSid",
"Effect": "Allow",
"Action": [
"logs:CreateLogStream",
"logs:PutLogEvents"
],
"Resource": [
"arn:aws:logs:::log-group:::",
"arn:aws:logs:::log-group:"
]
}
]
}
`

$3

Go to IAM Console and create user with the restricted policy.

Basic Usage

`js
import { Logger } from 'cloudwatch-front-logger'

const accessKeyId = 'XXXXXXXXXXXXXXXXXXXX'
const secretAccessKey = 'YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY'
const region = 'ap-northeast-1'
const logGroupName = ''

const logger = new Logger(accessKeyId, secretAccessKey, region, logGroupName)
logger.install()
`

Logs are collected from the following sources.

- Uncaught Error
- console.error() call
- Manual logger.onError() call
(See integration examples)

Advanced Usage

$3

By default, "anonymous" is used for logStreamName value.
If you wish allocating a unique stream for each user, you can use a method such as Canvas Fingerprint.
Pass a resolver function as logStreamNameResolver option value on install() call.

`js
import FingerprintJS from 'fingerprintjs'

logger.install({
async logStreamNameResolver() {
const fp = await FingerprintJS.load()
const { visitorId } = await fp.get()
return visitorId
},
})
`

$3

By default, messages are formatted into JSON string which has message and type.

`json5
{
"message": "Err: Something went wrong",
"type": "uncaught"
}
`

`json5
{
"message": "Something went wrong",
"type": "console",
"level": "error"
}
`

If you wish formatting them by yourself, pass a formatter function as messageFormatter option value on install() call. Note that you can cancel by returning null from the fuunction.

`js
import StackTrace from 'stacktrace-js'

logger.install({
async messageFormatter(e, info = { type: 'unknown' }) {
if (!e.message) {
return null
}

let stack = null
if (e.stack) {
stack = e.stack
try {
stack = await StackTrace.fromError(e, { offline: true })
} catch (_) {
}
}

return JSON.stringify({
message: e.message,
timestamp: new Date().getTime(),
userAgent: window.navigator.userAgent,
stack,
...info,
})
},
})
`

$3

By default, localStorage is used for caching logStreamName and nextSequenceToken.
Still localStorage has only synchronous API, asynchronous interfaces are also supported.
If you need to change storage implementation from localStorage, pass an instance as storage option value on install() call.

`js
import { AsyncStorage } from 'react-native'

logger.install({
storage: AsyncStorage,
})
`

Integration Examples

$3

`jsx
class LoggerComponent extends React.component {

componentDidCatch(e, info) {
this.props.logger.onError(e, {
...info,
type: 'react',
})
}

render() {
return this.props.children
}
}
`

`jsx



`

$3

`js
const createLoggerMiddleware = (logger) => (store) => (next) => (action) => {
try {
return next(action)
} catch (e) {
logger.onError(e, {
action,
type: 'redux',
})
}
}
`

`js
const store = createStore(
combineReducers(reducers),
applyMiddleware(createLoggerMiddleware(logger))
)
``