koa-log

HTTP request logger middleware for koa, refer to express/morgan and koa-logger

API

var logger = require('koa-log');
var morgan = logger.morgan;

Predefined Formats

There are various pre-defined formats provided:

combined

Standard Apache combined log output.

:remote-addr - :remote-user [:date[clf]] ":method :url HTTP/:http-version" :status :length ":referrer" ":user-agent"

common

Standard Apache common log output.

:remote-addr - :remote-user [:date[clf]] ":method :url HTTP/:http-version" :status :length

dev

Concise output colored by response status for development use. The :status token will be colored red for server error codes, yellow for client error codes, cyan for redirection codes, and uncolored for all other codes.

:method :url :status :response-time ms - :length

short

Shorter than default, also including response time.

:remote-addr :remote-user :method :url HTTP/:http-version :status :length - :response-time ms

tiny

The minimal output.

:method :url :status :length - :response-time ms

Tokens

Creating new tokens

To define a token, simply invoke morgan.token() with the name and a callback function. This callback function is expected to return a string value. The value returned is then available as ":type" in this case:

morgan.token('type', function(ctx){ return ctx.get('content-type'); })

Calling morgan.token() using the same name as an existing token will overwrite that token definition.

:date[format]

The current date and time in UTC. The available formats are:

• clf for the common log format ("10/Oct/2000:13:55:36 +0000")
• iso for the common ISO 8601 date time format (2000-10-10T13:55:36.000Z)
• web for the common RFC 1123 date time format (Tue, 10 Oct 2000 13:55:36 GMT)

If no format is given, then the default is web.

:http-version

The HTTP version of the request.

:method

The HTTP method of the request.

:referrer

The Referrer header of the request. This will use the standard mis-spelled Referer header if exists, otherwise Referrer.

:remote-addr

The remote address of the request. This will use req.ip, otherwise the standard req.connection.remoteAddress value (socket address).

:remote-user

The user authenticated as part of Basic auth for the request.

:response-time

The time between the request coming into morgan and when the response headers are written, in milliseconds.

:status

The status code of the response.

:url

The URL of the request. This will use req.originalUrl if exists, otherwise req.url.

:user-agent

The contents of the User-Agent header of the request.

morgan.compile(format)

Compile a format string into a function for use by morgan. A format string is a string that represents a single log line and can utilize token syntax. Tokens are references by :token-name. If tokens accept arguments, they can be passed using [], for example: :token-name[pretty] would pass the string 'pretty' as an argument to the token token-name.

Normally formats are defined using morgan.format(name, format), but for certain advanced uses, this compile function is directly available.

Examples

'use strict';
const Koa = require('koa');
const app = new Koa();
const koaLog = require('koa-log');


app.use(koaLog());

app.use(koaLog('dev'));
app.use((ctx, next) => {
	const delay = new Promise(function(resolve, reject) {
		setTimeout(resolve, 3000);
	});
	return delay.then(next);
});

// response

app.use(ctx => {
	ctx.body = 'Hello World';
});

app.listen(3000);

License

MIT