HTTP Middleware Logger
Express middleware, adds a child logger to each request.
Getting Started
npm install --save @cork-labs/http-middleware-loggerconst bunyan = require('bunyan');
const Logger = require('@cork-labs/monkfish-adapter-logger').Logger;
// your application setup
const logger = Logger.createLogger({ name: 'my-app', streams: [{ type:'console' }] });
const httpLogger = require('@cork-labs/http-middleware-logger');
const options = {};
this._express.use(httpLogger(config, logger));
// use a middleware such as onHeaders to log responses
this._express.use((req, res, next) => {
onHeaders(res, () => res.log());
next();
});
// your route
app.get('/path', (req, res, next) => {
req.logger.info(data, 'message');
})Provide an instance of @cork-labs/monkfish-adapter-logger.
It supports:
- child loggers (child contexts)
- multiple streams at once (e.g.: console, bunyan, files, ...)
API
A child logger is created per request, and trace information is added to the logger.
The request is immediately logged.
> my-app | Thu, 10 Jan 2019 23:51:35 GMT | INFO | HttpApi::request()
trace: {
"uuid": "5b42547e-bd2f-4090-896c-18edfd79f39b",
"current": "5efc8d65-2dd3-458c-8a46-96aa37985a4f"
}
--
request: {
"method": "GET",
"path": "/account/5a9578f91e0d4724ed57ffe3"
}
The child logger is exposed in req.logger and you can log further messages.
All messages contain the same trace object plus whatever data you provide to them.
16:29:19.279Z INFO az.auth: Service::handle()
trace: {
"uuid": "5b42547e-bd2f-4090-896c-18edfd79f39b",
"current": "5efc8d65-2dd3-458c-8a46-96aa37985a4f"
}
--
event: {
"type": "account.get",
"params": {
"id": "5a9578f91e0d4724ed57ffe3"
}
}
The essential monkfish-adapter-logger API:
-
req.logger.child(data = {})returns a new logger, containing all the parent context plus the provided optional data -
req.logger.set(key, value = undefined)- adds key to context data (avoid adding objects, keep it flat!) -
req.logger.debug('message', data = {})- logs debug level message, with adittional data (optional) -
req.logger.info('message', data = {})- same, info level -
req.logger.warn('message', data = {})- same, warning level -
req.logger.error('message', data = {}, err = ...)- same, error level, plus optional error (ideally a subclass of Error) -
req.logger.flat(prefix = '', obj)flattens the object for logging
res.log()
When the response is sent, invoke res.log().
You can use a middleware such as onHeaders to be notified when the response is sent.
this._express.use(httpLogger(config, logger));
// use a middleware such as onHeaders to log responses
this._express.use((req, res, next) => {
onHeaders(res, () => res.log());
next();
});The response log contains a number of configurable.
The severity of this message can be configured via options.severityMap.
> my-app | Thu, 10 Jan 2019 23:51:35 GMT | INFO | HttpApi::response()
trace: {
"uuid": "5b42547e-bd2f-4090-896c-18edfd79f39b",
"current": "5efc8d65-2dd3-458c-8a46-96aa37985a4f"
}
--
response: {
"status": 200
}
--
timing: {
"total": 20,
"routed": 5,
"handled": 15
}
Configuration
The middleware can be configured via an options object when calling its factory function.
const options = {
headers: {
message: 'http.request.received'
}
};
app.use(httpLogger(options));requestMessage (default: 'http request')
requestKey (default: 'request')
requestFields (default: { method: 'method', path: 'path' })
responsetMessage (default: 'http response')
responseKey (default: 'response')
responseTimingKey (default: 'timing')
responseFields (default: { status: 'statusCode' })
traceKey (default: 'trace')
traceFields (default: { uuid: 'uuid', current: 'path' })
severityMap (default: { })
Develop
# lint and fix
npm run lint
# run test suite
npm test
# lint and test
npm run build
# serve test coverage
npm run coverage
# publish a minor version
node_modules/.bin/npm-bump minorContributing
We'd love for you to contribute to our source code and to make it even better than it is today!
Check CONTRIBUTING before submitting issues and PRs.