Instrumenting route-start and route-done in DTrace cause restify to crash

[Smithx10]

Starting in restify version 7 dtrace will crash restify if you instrument route-start or route-done.

start application:

bruce.smith@Bruces-MacBook-Pro /g/f/r/f/src ❯❯❯ node api.js                                                                                                            ⏎ master ◼
{"name":"fibo-api","hostname":"Bruces-MacBook-Pro.local","pid":58139,"app_type":"fibo-restify","level":30,"msg":"ready on http://[::]:8080","time":"2018-04-23T15:21:52.441Z","v":0}

instrument the probe:

    bruce.smith@Bruces-MacBook-Pro /g/f/rest-fibo ❯❯❯ sudo dtrace -n 'restify58139:::route-start'                                                                            master ◼
dtrace: system integrity protection is on, some features will not be available

dtrace: description 'restify58139:::route-start' matched 1 probe

hit the api:

curl localhost:8080/api/fibo/4

node throws:

/git/for-virtu/rest-fibo/fibo/src/node_modules/restify/lib/router.js:346
            req.route.name,
                      ^

TypeError: Cannot read property 'name' of undefined
    at DTraceProbe.fire (/git/for-virtu/rest-fibo/fibo/src/node_modules/restify/lib/router.js:346:23)
    at Router._dtraceStart (/git/for-virtu/rest-fibo/fibo/src/node_modules/restify/lib/router.js:343:41)
    at Router.lookup (/git/for-virtu/rest-fibo/fibo/src/node_modules/restify/lib/router.js:78:10)
    at Server._runRoute (/git/for-virtu/rest-fibo/fibo/src/node_modules/restify/lib/server.js:906:36)
    at Server._afterPre (/git/for-virtu/rest-fibo/fibo/src/node_modules/restify/lib/server.js:888:10)
    at Immediate.preChainDone [as _onImmediate] (/git/for-virtu/rest-fibo/fibo/src/node_modules/restify/lib/server.js:856:14)
    at runCallback (timers.js:764:11)
    at tryOnImmediate (timers.js:734:5)
    at processImmediate (timers.js:716:5)
    at process.topLevelDomainCallback (domain.js:101:23)

[DonutEspresso]

@hekike it looks like dtraceStart expects req.route, but we haven't looked up the route yet when it gets fired. I think in the router migration there are probably a few of the dtrace hooks that haven't been migrated ?

[hekike]

It was also fired at the wrong place, here is a fix: #1659