nsqd: make importable

[kzvezdarov]

The changes in this PR split the nsqd application into an executable and a package (called nsqd), in the same manner as nsqlookupd.

[mreiferson]

@kzvezdarov thanks for getting this started.

It looks like travis is reporting test failures. Looking at the logs it seems like test.sh isn't able to start an nsqd instance... can you look into that?

[mreiferson]

As to your question on the ML, once we've got everything working, etc. we'll squash down the commits.

[kzvezdarov]

The last comit should fix the problem. test.sh was looking for the executable in the old location. I had an old executable lying around in nsqd which was causing the tests to pass and give me a false positive.

[mreiferson]

@kzvezdarov thanks, travis is happy 😄

I've gone through the public API that this change will now expose (by running go doc . in the nsqd top-level directory) and I think it would be prudent to clean up a few things:

• un-export ProtocolV2 struct
• export func (n *NSQD) getStats() (so external packages can get stats directly)
• un-export PeerInfo struct
• un-export LookupPeer struct
• un-export NewLookupPeer(...)
• un-export IdentifyEvent struct
• un-export IdentifyDataV2 struct
• un-export GUID int64
• un-export GUIDFactory struct
• un-export DiskQueue struct
• un-export NewDiskQueue(...)
• un-export DummyBackendQueue struct
• un-export NewDummyBackendQueue(...)
• un-export Context struct
• un-export ClientV2 struct
• un-export NewClientV2(...)
• un-export WriteMessageToBackend(...)

Let's see how the public API looks after that...

[kzvezdarov]

On it.

[kzvezdarov]

In unexporting the structs, should I also unexport their exported fields?

[mreiferson]

Good question, I don't think that's necessary though.

[kzvezdarov]

I can't reproduce the above error and I am not too sure what it means/where it could come from?

[mreiferson]

Yea, don't worry about it, looks like a flakey test. I'll poke around separately.

[mreiferson]

@kzvezdarov you wanna rebase/squash this down and see tests pass?

[kzvezdarov]

Seems well this time.

[mreiferson]

great, thanks for your contribution!