koa-grace-logger

koa-logger2

Logger middleware for http://github.com/koajs. Inspired by morgan from expressjs and apache.

Usage

Simplest example that will print basic information to standard output:

var logger = require('koa-logger2');
app.use(logger().gen); // will log to standard output by default

More advanced usage which will output more apache-like combined log:

var logger = require('koa-logger2');

var log_middleware = logger('ip [day/month/year:time zone] "method url protocol/httpVer" status size "referer" "userAgent" duration ms custom[unpacked]');
log_middleware.setStream(fs.createWriteStream(path.join(__dirname, 'logs/2014-09.log'), { flags: 'a' }));

app.use(log_middleware.gen); // !! note there are no () after gen

As a result you will get lines like:

123.45.67.89 [12/Sep/2014:22:12:26 +0200] "GET / HTTP/1.1" 301 22 "-" "Mozilla/5.0 (Android; Mobile; rv:31.0) Gecko/31.0 Firefox/31.0" 0 ms -

Later at any time you can call setStream again in order to replace stream you're writing to.

API

Just call the only function which is being exported:

logger([ format = " day/month time ip "method url protocol/httpVer" status size "referer" "userAgent" duration ms " ])

This will create logger object which has two properties - setStream method and gen. Formatters currently implemented are:

Formatter	Description (Example)
ip	IP address of the client
method	Request method (GET)
url	Request url (/)
status	Status code (200)
httpVer	Protocol version (1.1)
protocol	HTTP or HTTPS
size	Content-Length of response
referer	Referer header
userAgent	User-agent header
time	Current time in 24-hour format HH:MM:SS
day	Day of month 01-31
month	Short month name (Sep)
year	Year 4 digits (2014)
zone	Timezone offset (+0200)
duration	Duration of processing this request
custom[your.field]	Basically access anything you want from koa (ctx) object

setStream( stream.Writable )

Use this function to replace output stream for the logger (for example for log rotation). Please keep in mind that actual writing to the stream happens "on the way back".

gen

Returns generator function which should be used as middleware in your koaApp. ** NOTE: There are NO brackets () at the end. **

TODO

• support for auth-module
• unit tests
• better code documentation
• ...

License

MIT