Add appdash/nettrace package

[tcolgate]

First draft at tracer for adding events for an underlying net.Conn Still needs tests and documentation, but I'd like to know if you'd be interested in it if I tidy it up.

I'm using this as part of a benchmarking client for an API, which I realise is a bit of an odd use of appdash (it's all client side), but the code was easy to write and it seemed like it could be generally useful.

Feedback is welcome.

[slimsag]

Sounds like a reasonably well-fitted feature for Appdash. I have a few requests if you have the time:

• Would you be able to rename it to nettrace instead of netconntrace? I think that matches httptrace and sqltrace sub-packages better.
• Perhaps add some tests to ensure it works and package docs.
• Long term we should perhaps have a small example for it's usage in appdash/examples/cmd/netapp, but that can be added later.

Thanks for the PR! :smile:

[tcolgate]

I've split the Dial and net.Conn out into seperate files, and renamed as requested. I'll have a crack at writing some tests at the end of the week. (I've never got the hang of unit testing this kind of stuff so it'll be a good thing for me to do). I've got code using this in an internal project, so putting together an eample app should be pretty easy.

[slimsag]

Hey @tcolgate -- great work! I really like this! If you want any help or feedback on writing the tests just let me know, I'd be glad to help.

I added a bunch of comments on the first file regarding // comment style -- but they're very minor (and I can adjust them after merging if you don't want to). They also apply to the ConnWriteEvent type (the other file).

If you could put together a example app I would be very happy! If not just let me know, and I'll see if I can write one soon to verify that this API works pretty well.

Looking forward to your progress on this and to merging it! :smile:

[tcolgate]

Sorry this took a while, not had much spare time. Updated the comments, and removed the two NewConn(Read|Write)Event. Still need a unit test.

[slimsag]

Apologies for the late review. The code LGTM.

If you don't have time to write a unit test (or don't want to) I can merge this as-is and add one myself -- just let me know!

We really appreciate the PR! :smile:

[tcolgate]

@slimsag cheers, I'm going to hve a crack at the unit test. It'll be good practice.

[tcolgate]

feel free to merge first though, if you want to make it available.It might be a while before the test is ready (not got a lot of spare time in the next week or so, I will try today, if I don't get it done, it may be another week)

[tcolgate]

@slimsag I thought I'd update this and have a crack at adding some tests. Nothing too mind blowing yet, but I'll try and work on it. Will add Close() tracing too I think. I don't actually need this code any more, but it's fun to work on.

[slimsag]

@tcolgate Awesome! I appreciate it! If you ever feel like not working on it let me know and I can take over it. I think this will make a really good example on how Appdash can work in many areas, not just in HTTP applications :)

[slimsag]

I'm going to close this for now because it is stale. Once someone (incl. me) is ready to work on it, feel free to re-open / comment.

FWIW I do think this is a good change that we should make long-term.