[Users] firewall capability in openVZ/virtuozzo 7

[Vasily Averin]

By default we disable conntracks on host

# cat /etc/modprobe.d/vz.conf
options nf_conntrack ip_conntrack_disable_ve0=1

It protects host from in "conntrack overflow" situation:
when all conntracks on host are in use host admin is unable to connect on host via ssh.

Please feel free to enable it, it is quite safe for many cases.

Thank you,
	Vasily Averin

On 11.10.2016 13:22, Jehan Procaccia wrote:
> ok, that works fine with that:
> 
> # prlctl set MyCT11 --netfilter stateful
> Set netfilter: stateful
> The CT has been successfully configured.
> 
> and it is saved
> 
> # grep -i netfilter /vz/private/1d268e70-3597-4508-9e2a-903fc06b02a2/ve.conf
> NETFILTER="stateful"
> 
> inside the CT now I can issue firewall-cmd
> 
> CT-1d268e70 /# firewall-cmd --get-active-zones
> public
>   interfaces: eth0
> 
> Great !
> 
> Now, I realized that on the host machine, if I start firewalld I am locked out of my ssh session :-(
> although ssh service is open on all interfaces !
> 
> # firewall-cmd --zone=public --list-all
> public (default, active)
>   interfaces: br0 br1 br10 br11  em1 em2 p2p2 p2p2.11
>   sources:
>   services: dhcpv6-client ssh
>   ports:
>   masquerade: no
>   forward-ports:
>   icmp-blocks:
>   rich rules:
> 
> I missed something again ?
> 
> regards .
> 
> Le 11/10/2016 11:04, Vasily Averin a écrit :
>> Dear Jehan,
>>
>> OpenVZ container does  not require to enable additional capabilities,
>> default settings allows to use iptables inside container.
>>
>> However by default netfilter is restricted,
>> most likely you need to change it by using "prlctl set --netfilter"
>>
>>         --netfilter <disabled|stateless|stateful|full>
>>             Restrict access to iptable modules inside the Container.  The  fol-
>>             lowing modes are available:
>>             disabled  -- no modules are allowed.
>>             stateless  --  (default)  all modules except NAT and conntracks are
>>             allowed.
>>             stateful  -- all modules except NAT are allowed.
>>             full      -- all modules are allowed.
>>
>>
>> btw. prlctl works as "vzctl --save" in any cases, it saves the setting in configs.
>>
>> Thank you,
>>     Vasily Averin
>>
>> On 10.10.2016 22:42, Jehan Procaccia wrote:
>>> hello
>>>
>>> by default firewalld doesn't work on a fresh install container (centos7-x64)
>>>
>>> docs says:
>>> http://docs.virtuozzo.com/virtuozzo_7_users_guide/advanced-tasks/configuring-capabilities.html?highlight=firewall
>>> I guess I need to enable net_admin
>>> net_admin     Allows the administration of IP firewalls and accounting.     off
>>> as it it by default set to off
>>>
>>> but the command is deprecated
>>> # vzctl set MyCT11 --capability net_admin --save
>>> Warning: The --capability option is deprecated
>>>
>>> So I used prlctl (not proposed in the doc above !?)
>>>
>>> # prlctl set MyCT11 --capability net_admin:on
>>> Set capabilities: NET_ADMIN:on
>>> The CT has been successfully configured.
>>>
>>> but still in the CT
>>> /# firewall-cmd --get-active-zones
>>> nothing
>>> /# firewall-cmd --reload
>>> Error: '/sbin/iptables -w2 -t filter -I INPUT 1 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT' failed: iptables: No chain/target/match by that name.
>>> as if NET_ADMIN capability is not save permanently in the CT definition
>>>
>>> what is the equivalent of vzctl --save with prlctl ?
>>> or I mess somewhere else ?
>>>
>>> Regards .
>>>
>>>
>>>
>>>
>>>
>>>
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> 
> 
>