Re: [Qemu-devel] [PATCH v3] qemu-ga: add guest-get-osrelease command

[Vinzenz Feenstra]

Hi Michael,

It’d be really great to get your opinion on this matter. Thanks!

> On Apr 3, 2017, at 5:17 PM, Marc-André Lureau <address@hidden> wrote:
> 
> Hi
> 
> On Fri, Mar 31, 2017 at 3:41 PM Eric Blake <address@hidden 
> <mailto:address@hidden>> wrote:
> On 03/31/2017 05:19 AM, Vinzenz 'evilissimo' Feenstra wrote:
> > From: Vinzenz Feenstra <address@hidden <mailto:address@hidden>>
> >
> > Add a new 'guest-get-osrelease' command to report OS information in the
> > os-release format. As documented here:
> > https://www.freedesktop.org/software/systemd/man/os-release.html 
> > <https://www.freedesktop.org/software/systemd/man/os-release.html>
> >
> > The win32 implementation generates the information.
> > On POSIX systems the /etc/os-release or /usr/lib/os-release files
> > content is returned when available and gets extended with the fields:
> > - QGA_UNAME_RELEASE which is the content of `uname -r`
> > - QGA_UNAME_VERSION which is the content of `uname -v`
> > - QGA_UNAME_MACHINE which is the content of `uname -m`
> >
> > Here an example for a Fedora 25 VM:
> >
> > virsh # qemu-agent-command F25 '{ "execute": "guest-get-osrelease" }'
> > {"return":{"content":"NAME=Fedora\nVERSION=\"25 (Server Edition)\"\n
> > ID=fedora\nVERSION_ID=25\nPRETTY_NAME=\"Fedora 25 (Server Edition)\"\n
> > ANSI_COLOR=\"0;34\"\nCPE_NAME=\"cpe:/o:fedoraproject:fedora:25\"\n
> > HOME_URL=\"https://fedoraproject.org/\ <https://fedoraproject.org/%5C>"\n
> > BUG_REPORT_URL=\"https://bugzilla.redhat.com/\ 
> > <https://bugzilla.redhat.com/%5C>"\n
> > REDHAT_BUGZILLA_PRODUCT=\"Fedora\"\n
> > REDHAT_BUGZILLA_PRODUCT_VERSION=25\nREDHAT_SUPPORT_PRODUCT=\"Fedora\"\n
> > REDHAT_SUPPORT_PRODUCT_VERSION=25\n
> > PRIVACY_POLICY_URL=https://fedoraproject.org/wiki/Legal:PrivacyPolicy\n 
> > <https://fedoraproject.org/wiki/Legal:PrivacyPolicy%5Cn>
> > VARIANT=\"Server Edition\"\nVARIANT_ID=server\n\n
> > QGA_UNAME_RELEASE=\"4.8.6-300.fc25.x86_64\"\n
> > QGA_UNAME_VERSION=\"#1 SMP Tue Nov 1 12:36:38 UTC 2016\"\n
> > QGA_UNAME_MACHINE=\"x86_64\"\n"}}
> 
> Uggh. This is a step backwards.  Now you are requiring the end user to
> parse a raw string, instead of giving them the information already
> broken out as a JSON dictionary.
> 
> yes otoh, it uses an existing standard to retrieve various guest os release 
> informations, which existing tool may know how to handle.
> 
> (I feel partially guilty about it since I suggested it, mainly in a 
> discussion over irc and Vinzenz adopted it)
> 
> The format is fairly straightforward to parse, but perhaps it should be sent 
> as a JSON dict instead? However, that would mean that the list of keys is 
> limited by what QGA protocol defines, and the agent would have to parse the 
> file himself. And we would have to duplicate the documentation etc..
> 
> I would rely on the XDG format instead, given its simplicity, extensibility 
> and documentation that fits the job nicely imho.
>  
> -- 
> Marc-André Lureau

--
Vinzenz Feenstra
Senior Software Developer
Red Hat Czech