beaver-logger
Front-end logger, which will:
- Buffer your front-end logs and periodically send them to the server side
- Automatically flush logs for any errors or warnings
This is a great tool to use if you want to do logging on the client side in the same way you do on the server, without worrying about sending off a million beacons. You can quickly get an idea of what's going on on your client, including error cases, page transitions, or anything else you care to log!
Overview
Setup
var $logger = beaver.Logger({
url: "/my/logger/url",
});
Basic logging
$logger.info(<event>, <payload>);
Queues a log. Options are debug
, info
, warn
, error
.
For example:
$logger.error('something_went_wrong', { error: err.toString() })
$logger.track(<payload>);
Call this to attach general tracking information to the current page. This is useful if the data is not associated with a specific event, and will be sent to the server the next time the logs are flushed.
$logger.metric(<event>, <payload>);
Queues a metric
Advanced
$logger.addMetaBuilder(<function>);
Attach a method which is called and will attach general information to the logging payload whenever the logs are flushed
$logger.addMetaBuilder(function () {
return {
current_page: getMyCurrentPage(),
};
});
$logger.addPayloadBuilder(<function>);
Attach a method which is called and will attach values to each individual log's payload whenever the logs are flushed
$logger.addPayloadBuilder(function () {
return {
performance_ts: window.performance.now(),
};
});
$logger.addTrackingBuilder(<function>);
Attach a method which is called and will attach values to each individual log's tracking whenever the logs are flushed
$logger.addTrackingBuilder(function () {
return {
pageLoadTime: getPageLoadTime(),
};
});
$logger.addHeaderBuilder(<function>);
Attach a method which is called and will attach values to each individual log requests' headers whenever the logs are flushed
$logger.addHeaderBuilder(function () {
return {
"x-csrf-token": getCSRFToken(),
};
});
$logger.flush();
Flushes the logs to the server side. Recommended you don't call this manually, as it will happen automatically after a configured interval.
Installing
- Install via npm
npm install --save beaver-logger
- Include in your project
<script src="/js/beaver-logger.min.js"></script>
or
let $logger = require("beaver-logger");
Configuration
Full configuration options:
var $logger = beaver.Logger({
// Url to send logs to
url: "/my/logger/url",
// Prefix to prepend to all events
prefix: "myapp",
// Log level to display in the browser console
logLevel: beaver.LOG_LEVEL.WARN,
// Interval to flush logs to server
flushInterval: 60 * 1000,
// Use sendBeacon if supported rather than XHR to send logs; defaults to false
enableSendBeacon: true,
});
Server Side
beaver-logger includes a small node endpoint which will automatically accept the logs sent from the client side. You can mount this really easily:
let beaverLogger = require("beaver-logger/server");
myapp.use(
beaverLogger.expressEndpoint({
// URI to recieve logs at
uri: "/api/log",
// Custom logger (optional, by default logs to console)
logger: myLogger,
// Enable cross-origin requests to your logging endpoint
enableCors: false,
})
);
Or if you're using kraken, you can add this in your config.json
as a middleware:
"beaver-logger": {
"priority": 106,
"module": {
"name": "beaver-logger/server",
"method": "expressEndpoint",
"arguments": [
{
"uri": "/api/log",
"logger": "require:my-custom-logger-module"
}
]
}
}
Custom backend logger
Setting up a custom logger is really easy, if you need to transmit these logs to some backend logging service rather than just logging them to your server console:
module.exports = {
log: function (req, level, event, payload) {
logSocket.send(
JSON.stringify({
level: level,
event: event,
payload: payload,
})
);
},
};
Data Flow
flowchart TD
A[Client-Side Log statement] --> B[beaver-logger/client]
B[beaver-logger/client] --> C[beaver-logger/server]
C[beaver-logger/server] --> D[your-custom-logger]
D[your-customer-logger] --> E[Backend 1]
D[your-customer-logger] --> F[Backend 2]
G[Server-Side Log statement] --> D[your-custom-logger]