WARNING strconv.ParseInt on kernel with LOCALVERSION set

[rla]

So far this has been reported and fixed for the special cases only:

• strconv.ParseInt: parsing "joyent": invalid syntax #455 - LOCALVERSION with separator -;
• uname -r parse warning #1643 - LOCALVERSION with separator .

Today I ran (0.7.5) on a kernel with not LOCALVERSION separator (with uname 3.12.8tag) where tag is arbitrary non-integer word. This will give warning:

strconv.ParseInt: parsing "8tag": invalid syntax

There is nothing in the kernel compilation process that requires LOCALVERSION to be prefixed/separated with . or - (a good convention but not always done).

[tianon]

I've tagged this as helpwanted - it should be a reasonably easy fix if someone wants to take a stab at it. It would be an excellent first foray into Go, too. Just be sure to comment here if you're planning to work on it and we'll be happy to help with any issues you might run into!

[rla]

Indeed, I'm not a Go programmer (yet) but I do not fear Go or coding. I haven't had time to look yet where is the flavour used (seems that's what it's called in the code) and what could be possible backwards-compatibility issues. Current cases must stay but should we also allow additional separators (+ and _?) to . and - or just take plain string when those two cases above do not match.

[tianon]

I think it's only used for feature/bug compatibility comparisons, so stripping any non-numeric prefix should be appropriate behavior.

[chazomaticus]

Hope I didn't step on your toes, @rla -- I've been looking to get my feet wet in docker and real-world go, and this seemed like an easy fix, so I just went for it.

@tianon, the easiest thing to do seemed to be just ignoring the kernel "flavor" entirely. It didn't seem to be used anywhere, although I haven't been using docker for very long so perhaps I missed something.

[tianon]

It's included in the output of docker info, where it's turned out to be useful every now and then for determining the specific "kernel flavor" (ie, for kernels compiled with the gentoo patchset, we typically get -gentoo as the flavor).

[chazomaticus]

Gotcha. I'll define "flavor" as anything that comes after the minor version number in the string and print it verbatim.

I'll also use Sscanf like you mention in the PR, 'cause that'll be way easier!

[rla]

@chazomaticus, no problems. I'm happy that this gets fixed!

[chazomaticus]

I believe this is fixed from #3695. Not sure if it's still open for any reason other than that I forgot to include the magic "fixes #..." text in the PR.

[tianon]

Indeed, thanks!