client: transport: fix tlsconfig Clone() on different Golang versions

[AkihiroSuda]

Fix #26410

Signed-off-by: Akihiro Suda suda.akihiro@lab.ntt.co.jp

[AkihiroSuda]

@tonistiigi docker/engine-api#382

[feilengcui008]

@AkihiroSuda actually it seems that go1.7 has tls.Config.clone, so can we use this directly and use tls.Config.Clone for go version >=1.8, and for go version <=1.6, we can use the code in tlsconfig_clone_go17.go,

[AkihiroSuda]

@feilengcui008 clone can be called only from tls package itself

[feilengcui008]

@AkihiroSuda sorry, I didn't notice this...another thing is can we use the !go1.6 and !go1.7 in tlsconfig_clone.go instead of go1.8 since we can avoid continuing adding go1.9... if go upstream doesn't change this interface

[justincormack]

Why not use golang:alpine as the base image for the man page build (or explicitly golang:1.7-alpine) as this has Go 1.7 already? (Would also need to check the other archs).

[AkihiroSuda]

@justincormack yes, I was just actually thinking that 😃
So I'm going to replace this PR with #26416

[runcom]

I feel this is still needed though since I'm not able to compile anymore and #26410

[runcom]

ping @justincormack @crosbymichael

[runcom]

@AkihiroSuda could you please edit the commit message?

[runcom]

@justincormack @crosbymichael Golang in Fedora 23 is still at Go 1.5.4 (http://koji.fedoraproject.org/koji/packageinfo?packageID=16224) for us still and in F24 we're at Go 1.6.x

[AkihiroSuda]

@runcom done

@feilengcui008 go1.8 will continue to work for Go 1.9`.

poc: go1.6 work for Go 1.7

main.go:

package main

import "runtime"

func main() { println("hello " + runtime.Version()) }

go16.go (and suppose that there are go17.go and go18.go correspondingly)

// +build go1.6

package main

func init() { println("hello from +build go1.6") }

demo

$ go version
go version go1.7 linux/amd64
$ ls
go16.go  go17.go  go18.go  main.go
$ go build
$ ./demo
hello from +build go1.6
hello from +build go1.7
hello go1.7

[crosbymichael]

can you move these build tags to the same line? or why is this needed at all? isn't it enough to say only build for go1.6 ?

[tonistiigi]

@crosbymichael go1.6 actually means go1.6+

[AkihiroSuda]

The line means go1.6 && !go1.7.
If we split the line it would become go1.6 || !go1.7
https://golang.org/pkg/go/build/

And even on Go 1.7, the go1.6 tag is true, that's why we need !go1.7

[crosbymichael]

+1 thanks

[tonistiigi]

in one line it would be go1.6,!go1.7

[AkihiroSuda]

thank you, updated

[AkihiroSuda]

@justincormack

Why not use golang:alpine as the base image for the man page build (or explicitly golang:1.7-alpine) as this has Go 1.7 already? (Would also need to check the other archs).

Can it be delayed until Ubuntu 16.10 Yakkety Yak that provides Go 1.7 is released (for other archs)?
https://launchpad.net/ubuntu/+source/golang-1.7/1.7-2ubuntu1

[AkihiroSuda]

I'm not sure why there was !windows here, Clone() seems supporting windows.
golang/go@d24f446

[crosbymichael]

LGTM

[tonistiigi]

LGTM