RFC: sysctl fixes

RFC: sysctl fixes

[Marian Marinov]

Hello,
we are running hundreds of containers and we got some valid requests from customers that want to be able to change their
container's hostname using the sysctl command.

The current implementation does not allow each UTS namespace to change its own hostname.

So we sponsored the development of fix for this issue.

Please checkout the changes here:
  https://github.com/1HLtd/linux/compare/b24e2bdde4af656bb0679a101265ebb8f8735d3c...sysctl-hostname-fixes

If this fix is acceptable I'll send the patches as it is common. But first I want to know if you think this is the way
to go.

Thank you,
Marian

Re: RFC: sysctl fixes

[Stephan Mueller]

Am Mittwoch, 4. März 2015, 15:18:19 schrieb Marian Marinov:

Hi Marian,

>Hello,
>we are running hundreds of containers and we got some valid requests
>from customers that want to be able to change their container's
>hostname using the sysctl command.
>
>The current implementation does not allow each UTS namespace to change
>its own hostname.
>
>So we sponsored the development of fix for this issue.
>
>Please checkout the changes here:
> 
>https://github.com/1HLtd/linux/compare/b24e2bdde4af656bb0679a101265ebb
>8f8735d3c...sysctl-hostname-fixes
>
>If this fix is acceptable I'll send the patches as it is common. But
>first I want to know if you think this is the way to go.

The description in http://lwn.net/Articles/531381/ does not work?
>
>Thank you,
>Marian
>
>--
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Ciao
Stephan

Re: RFC: sysctl fixes

[Marian Marinov]

On 03/04/2015 05:48 PM, Stephan Mueller wrote:
> Am Mittwoch, 4. März 2015, 15:18:19 schrieb Marian Marinov:
>
> Hi Marian,
>
>> Hello,
>> we are running hundreds of containers and we got some valid requests
> >from customers that want to be able to change their container's
>> hostname using the sysctl command.
>>
>> The current implementation does not allow each UTS namespace to change
>> its own hostname.
>>
>> So we sponsored the development of fix for this issue.
>>
>> Please checkout the changes here:
>>
>> https://github.com/1HLtd/linux/compare/b24e2bdde4af656bb0679a101265ebb
>> 8f8735d3c...sysctl-hostname-fixes
>>
>> If this fix is acceptable I'll send the patches as it is common. But
>> first I want to know if you think this is the way to go.
> The description in http://lwn.net/Articles/531381/ does not work?

Stephan, the users can change the hostname of the container using the hostname command. I can also change their hostname
when I'm creating the containers.
However the customers need to be able to change the hostname of the machine using valid system command:

sysctl kernel.hostname=newhost
sysctl kernel.domainname=newdomain

Both of these commands try to talk to the kernel via the /proc filesystem. This is why we propose these fixes.
Without them, only the root on the host node can do this.

Correct me, if I'm wrong.

Marian

>> Thank you,
>> Marian
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-kernel"
>> in the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>> Please read the FAQ at  http://www.tux.org/lkml/
>
> Ciao
> Stephan
>
>