[v*] Healthcheck goroutine leaks

[utrack]

Hi! This PR fixes goroutine leaks caused by healthcheck not using ctx properly.
I've managed to reproduce it via tests.

[olivere]

That looks interesting. Thanks for reporting/fixing it. BTW: Tests fail for Go 1.7 because http.Server in 1.7 doesn't have a Shutdown method.

[utrack]

Hmm. Stumbled upon something re: golang/go#20668.

[olivere]

@utrack That works as expected here: Context is canceled.

$ go run main.go
Get http://127.0.0.1:57834/: context deadline exceeded
true

[utrack]

@olivere on Go 1.8 it works OK, but fails on 1.7.

[olivere]

@utrack Oh, I see.

[utrack]

I've also prepared v2 backport, should I open up another PR?

[utrack]

@olivere Fixed tests for all versions. It's not possible to monitor leaks directly on Go pre-1.8, so I'm using side effects to monitor stuck connections on pre-1.8.

Seems Context is never canceled on 1.7 on server's side because it was not implemented then (but context itself is present in the request). Huh.

[olivere]

@utrack Okay, thanks for figuring this out. Can you do three more things for me to merge this into v5:

1. As far as I can see it, you only have a test to check leaks for healthcheck. Can you also add a test for the sniffNode?
2. Can you please rename the test for healthcheck from TestRoutineLeaks to TestClientHealthcheckTimeout (or something more expressive). The test for the sniffer should be something like TestClientSnifferTimeout.
3. Can you move the tests to the end of the other TestClientHealthcheck... (and TestClientSniffer...) tests.

Then we can put together PRs for v2 and v3, or I'll do this in a batch.

[utrack]

Sure, done @olivere

[olivere]

Merged and will be published soon. Thanks again!

[olivere]

@utrack Do you mind to review #545 (and this commit)? It's this PR backported into elastic.v3.

I will also backport to elastic.v2 later with #546, after merging #503 first.

[utrack]

Reviewed everything :) Looks good, thank you for the client!

[olivere]

@utrack Thanks. Have a nice weekend. cu.

[wtfiwtz]

 % go build
# gopkg.in/olivere/elastic.v3
../gopkg.in/olivere/elastic.v3/client.go:835: (*http.Request)(req).WithContext undefined (type *http.Request has no field or method WithContext)
../gopkg.in/olivere/elastic.v3/client.go:986: (*http.Request)(req).WithContext undefined (type *http.Request has no field or method WithContext)

Looks like this breaks Go 1.6.2... I'm using elastic.v3... Upgrading Go to 1.8.3 resolved it...

 % wget https://storage.googleapis.com/golang/go1.8.3.linux-amd64.tar.gz
 % sudo tar -C /usr/local -xzf go1.8.3.linux-amd64.tar.gz
 % sudo mv /usr/bin/go /usr/bin/go1.6
 % sudo ln -s /usr/local/go/bin/go /usr/bin/go
 % go version
go version go1.8.3 linux/amd64
 % go build
 %

[olivere]

@wtfiwtz I see. However, 1.6 is no longer supported. I try to support the current and previous versions of Go (while Go itself even only supports the current version). From my experience, updating Go is nowhere as critical as in other environments.

[caseyw]

Note that this bit me as well. I've updated to 1.8 and everything compiled.

Thanks,

-c