manowar

Man O' War Logger

Have difficulty matching concurrent request event logs?

This module provides a live logger that indents each request's logs a uniform amount, connecting them all along a line. (or tendril on a Portugese Man O' War!)

This helps visualize a few things:

1. in what order async events occur ...in sync (so this isn't applicable to true parallelism in, say, web workers)
2. which requests generated which logs in concurrent-traffic scenarios, supplemented by a correlation_id for records
3. how long requests take
4. file line references generating logs
5. also it is colorful

This requires a few things to work:

• that you use the provided cc() logger, which is a terse, icon-able, chalk-colorable, extendable way to log things
  • (this also provides cc.sql, a log format ideal to plug into dbq, should you use that)
• that you include the requestLogger express middleware atop your router (or above all the routes you want logs for), which itself does a few things:
  • initiate the request's indentation, which is maintained until it replies or dies
  • log out some req info
  • kill requests that take longer than forceRequestKillAfter milliseconds (defaults to 10 seconds)
  • times requests for reference

Usage & Options

var {cc,requestLogger}=require("manowar")({
        //option:default
        ellipsize:true //cut off log lines once they exceed window width
        ,forceRequestKillAfter:10000//kill requests that take longer than this many milliseconds. Falsy = never.
        ,logEachReq:(req,res)=>false //a fxn for you to customize the incoming request log. Return false to defer to plugin default
        ,overrideIconsWith:"" //some displays don't correctly space icons & break the line display. Override them here
        ,logBody:true //whether to log request bodies
        ,fileNameSize:20 //max width to allow for file names on the left
        ,fileLineFilter:false //if you need a custom stacktrace filter to get the file name
        ,maxIdLength:11 //length of id col
        ,idMaker:require('shortid').generate //if you want to supply IDs your own way
        ,widthFudgeFactor:0//maybe process.stdout.columns lies on your box
        ,logSync:false//fs.writeSync vs console.log
        ,cc:{//any custom logging shortcuts you'd like.
            //coming soon
        }
    })
    ,app=express()
    ,router=express.Router()
 
router.use(requestLogger)
    //[then add your routes, use logging wherever...like:]
    .get("/*",(req,res)=>{
        cc(`logging a special message!`)
        res.send("howdy")
    })
 
 
app.use(router)
 
 

Logging defaults

cc('text') logging works, but extra colors & icons are available at cc.* (if you leave icons on):

Additionally:

• cc.chalk exists for you to stylize additional logs locally with chalk
• cc.namespace will give you access to the current cls-hooked namespace manowar set up to manage indentation, should you like to use it or attach more info in a local scope.