Subject: Re: [vserver] call method of host in guest os
From: "Nicolas Cadou" <ncadou@cobi.net>
Date: Sat, 13 Dec 2008 19:38:08 -0500
Sat, 13 Dec 2008 19:38:08 -0500
No need to mount anything. I don't know where your vservers are located in your filesystem,
mine are in /var/lib/vservers, so in my case the host could just write a file in /var/lib/vservers/guest1/var/tmp/file,
and the guest would just see it as /var/tmp/file.

And the nice thing with inotify tools is that they allow the host to react to certain
controlled, very limited conditions initiated by the guest, making the whole process
pretty secure, as the guest doesn't actually call anything on the host.

Nicolas Cadou

Cobi Informatique, inc.
http://www.cobi.net

Tel: (450) 266-2420 (305)
Fax: (450) 266-2415

----- Original Message -----
From: LynnOS <lynnos@tong-ji.org>
To: vserver@list.linux-vserver.org <vserver@list.linux-vserver.org>
Sent: Sat Dec 13 19:09:57 2008
Subject: Re: [vserver] call method of host in guest os

On Sun, Dec 14, 2008 at 7:39 AM, Nicolas Cadou <ncadou@cobi.net> wrote:
> Maybe you can have the host drop a file with the information you need
> somewhere within the guest's filesystem.

how i can make the file dropped by host visible for guest os ? though
mount command?

thanks


> You could do that using a cron job on the host if you want it updated
> regularly. Or you could have the guest request a refresh by touching a file
> and have the host detect the request using the kernel inotify mechanism.
>
> You could also ssh into the host from the guest, but it is not very secure.
>
> Nicolas Cadou
>
> Cobi Informatique, inc.
> http://www.cobi.net

> Tel: (450) 266-2420 (305)
> Fax: (450) 266-2415
>
> ----- Original Message -----
> From: LynnOS <lynnos@tong-ji.org>
> To: vserver@list.linux-vserver.org <vserver@list.linux-vserver.org>
> Sent: Sat Dec 13 18:15:28 2008
> Subject: Re: [vserver] call method of host in guest os
>
> Yes,you see my request
>
> But why is that impossible?
>
> I want to read some information through calling method of host,not
> change any to host
>
>
> Thanks
>
>
> On Sat, Dec 13, 2008 at 11:18 PM, Guenther Fuchs <vserver@muh.at> wrote:
>> Hi there,
>>
>> on Saturday, December 13, 2008 at 9:14:29 AM there was posted:
>>
>> L> Is that possible call method of host  in guest os?
>> L> As we know that in host os we can call guest method
>>
>> As far as I understand your request, you would like (example)
>>
>> .) to call a command located and in context of host OS out from one
>>   of the guests
>>
>> As far as I understand the design (and I hope I understood this
>> correctly): NO. This never should be possible as per my opinion
>> anyway.
>>
>> --
>> regards 'n greez,
>>
>> Guenther Fuchs
>> (aka "muh" and "powerfox")
>>
>>
>
>
>
> --
> OpenEmbedded,Linux vserver,Python
>



-- 
OpenEmbedded,Linux vserver,Python

Re: [vserver] call method of host in guest os

No need to mount anything. I don't know where your vservers are located in your filesystem, mine are in /var/lib/vservers, so in my case the host could just write a file in /var/lib/vservers/guest1/var/tmp/file, and the guest would just see it as /var/tmp/file.

And the nice thing with inotify tools is that they allow the host to react to certain controlled, very limited conditions initiated by the guest, making the whole process pretty secure, as the guest doesn't actually call anything on the host.

Nicolas Cadou

Cobi Informatique, inc.
http://www.cobi.net
Tel: (450) 266-2420 (305)
Fax: (450) 266-2415

----- Original Message -----
From: LynnOS <lynnos@tong-ji.org>
To: vserver@list.linux-vserver.org <vserver@list.linux-vserver.org>
Sent: Sat Dec 13 19:09:57 2008
Subject: Re: [vserver] call method of host in guest os

On Sun, Dec 14, 2008 at 7:39 AM, Nicolas Cadou <ncadou@cobi.net> wrote:
> Maybe you can have the host drop a file with the information you need
> somewhere within the guest's filesystem.

how i can make the file dropped by host visible for guest os ? though
mount command?

thanks


> You could do that using a cron job on the host if you want it updated
> regularly. Or you could have the guest request a refresh by touching a file
> and have the host detect the request using the kernel inotify mechanism.
>
> You could also ssh into the host from the guest, but it is not very secure.
>
> Nicolas Cadou
>
> Cobi Informatique, inc.
> http://www.cobi.net
> Tel: (450) 266-2420 (305)
> Fax: (450) 266-2415
>
> ----- Original Message -----
> From: LynnOS <lynnos@tong-ji.org>
> To: vserver@list.linux-vserver.org <vserver@list.linux-vserver.org>
> Sent: Sat Dec 13 18:15:28 2008
> Subject: Re: [vserver] call method of host in guest os
>
> Yes,you see my request
>
> But why is that impossible?
>
> I want to read some information through calling method of host,not
> change any to host
>
>
> Thanks
>
>
> On Sat, Dec 13, 2008 at 11:18 PM, Guenther Fuchs <vserver@muh.at> wrote:
>> Hi there,
>>
>> on Saturday, December 13, 2008 at 9:14:29 AM there was posted:
>>
>> L> Is that possible call method of host  in guest os?
>> L> As we know that in host os we can call guest method
>>
>> As far as I understand your request, you would like (example)
>>
>> .) to call a command located and in context of host OS out from one
>>   of the guests
>>
>> As far as I understand the design (and I hope I understood this
>> correctly): NO. This never should be possible as per my opinion
>> anyway.
>>
>> --
>> regards 'n greez,
>>
>> Guenther Fuchs
>> (aka "muh" and "powerfox")
>>
>>
>
>
>
> --
> OpenEmbedded,Linux vserver,Python
>



--
OpenEmbedded,Linux vserver,Python