[SR-Users] Kamailio IMS as kubernetes pods

David Villasmil david.villasmil.work at gmail.com
Thu Aug 27 14:06:10 CEST 2020


Hello Abdirahman,

Thanks for replying.

Do you mean if I create a service for the label selector of what’s running
in the pod, but ser ClusterIP: None, when another pod tries to resolve that
service, it will get the actual IP of the running POD?


On Wed, 26 Aug 2020 at 18:02, Abdirahman A. Osman <abdirahman.osm at gmail.com>
wrote:

> Hi Pavithra,
>
> Since POD IPs change, you have to rely on DNS records. To have a fixed DNS
> name like
>
> kamailio.kamalio-service.namespace.svc.cluster.local
>
>
>
> for a pod you will have to use StatefullSet, so the pod DNS name doesn't
> change. Also you have to use Services and set it to ClusterIP: none, it
> will turn your pods to headless services and no load balancing is involved.
> and from my understanding you will be able to reach each POD directly
> through the DNS name.
> https://kubernetes.io/docs/concepts/services-networking/service/
>
> and don't forget to set  your /etc/resolv.conf with the kubedns IP address.
>
> Abdirahman
>
>
>
> On Wed, 26 Aug 2020 at 12:45, Pavithra Mohanraja <pavimohan3004 at gmail.com>
> wrote:
>
>> Hi Abdirahman,
>>
>> Do you mean , if I set clusterIP as None, then kubedns server will be
>> pointing to pod ip so that kubedns/coredns will use pod ip for pod
>> communication instead of service IP.
>>
>>
>> Is my understanding correct? From your explanation.
>>
>> If this is the case, pod ip will be changing whenever I launch the pods .
>> How that can be resolved.
>>
>> Could you kindly helo me with this?
>>
>>
>> Thanks,
>> Pavithra
>>
>> On Wed, Aug 26, 2020, 9:26 PM Abdirahman A. Osman <
>> abdirahman.osm at gmail.com> wrote:
>>
>>> David,
>>>
>>>
>>>
>>> Assuming those are pod ips. Using services doesn’t work
>>>>
>>>> since the dns name will resolve to a k8s service ip and no the actual
>>>>
>>>> pod running the service.
>>>>
>>>
>>> If you set   *clusterIP: None* in the services, you will get POD IP.
>>>
>>>
>>>
>>>
>>>
>>> Abdirahman
>>>
>>>
>>>
>>> On Wed, 26 Aug 2020 at 10:48, Pavithra Mohanraja <
>>> pavimohan3004 at gmail.com> wrote:
>>>
>>>> Hi,
>>>> Thanks for the answers.
>>>> @David has got my question.
>>>>
>>>> I have a seperate dns server running in my pcscf pod . So in my
>>>> /etc/resolv.conf file , I would be configuring
>>>> nameserver <pcscf pod ip>
>>>> in all other cscf pods as well for communication.
>>>>
>>>>
>>>>
>>>> My question here is how to change the dns server pointing to cluster ip
>>>> so that my domain name for IMS will be pointing to coredns itself. It will
>>>> restrict me from using pod IP since it changes everytime.
>>>>
>>>>
>>>> @David, can you please tell me the last two lines briefly. I did not
>>>> get it.how you configured . You mean to say still you are using pod Ip.
>>>>
>>>>
>>>> On Wed, Aug 26, 2020, 8:02 PM David Villasmil <
>>>> david.villasmil.work at gmail.com> wrote:
>>>>
>>>>> I’ve been trying to figure this out as well.
>>>>> I haven’t yet found a way of publishing to kube-dns the pod IP of the
>>>>> running service.
>>>>>
>>>>> I.e.:
>>>>> kamailio.whatever.local on ip 10.0.0.1
>>>>> Rtpengine.whatever.local on ip 10.0.0.2
>>>>> Appserver.whatever.local on 10.0.0.3
>>>>>
>>>>> Assuming those are pod ips. Using services doesn’t work since the dns
>>>>> name will resolve to a k8s service ip and no the actual pod running the
>>>>> service.
>>>>>
>>>>> Assigning IPs hardcoded doesn’t work either since it might change if
>>>>> the docker changes pod. I can have multiple modes on which a service can
>>>>> run, but only one service (kamailio, rtpengine, appserver, etc) will run on
>>>>> a given pod.
>>>>>
>>>>> On Wed, 26 Aug 2020 at 15:18, Abdirahman A. Osman <
>>>>> abdirahman.osm at gmail.com> wrote:
>>>>>
>>>>>> Hi
>>>>>>
>>>>>> Pavithra
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> You can use the kubedns/CoreDNS of the kubernetes cluster to resolve
>>>>>> Internal DNS records of the pods.To assign DNS records for each POD you
>>>>>> have to deploy a service and set the ClusterIP: none. and the dns record
>>>>>> will be something like kamailio.kamalio-service.platform.svc.cluster.local
>>>>>> which is the podname.servicename.namespace.svc.cluster.local
>>>>>>
>>>>>> In the resolve.conf you will put the kubeDNS/CoreDNS IP as the
>>>>>> nameserver.  You can set this in the kubernetes manifest file
>>>>>>
>>>>>>       dnsPolicy: "None"
>>>>>>       dnsConfig:
>>>>>>         nameservers:
>>>>>>           - 10.34.0.1 (
>>>>>>
>>>>>> kubeDNS/CoreDNS )
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> Abdirahman
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Tue, 25 Aug 2020 at 15:34, Sergey Safarov <s.safarov at gmail.com>
>>>>>> wrote:
>>>>>>
>>>>>>> I am not k8s developer.
>>>>>>> So cannot provide detailed instructions. Just my point of view.
>>>>>>>
>>>>>>> You can look
>>>>>>> https://kubernetes.io/docs/concepts/extend-kubernetes/operator/
>>>>>>> https://www.magalix.com/blog/creating-custom-kubernetes-operators
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Tue, Aug 25, 2020 at 7:41 PM Pavithra Mohanraja <
>>>>>>> pavimohan3004 at gmail.com> wrote:
>>>>>>>
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> It would be helpful if you could elaborate what has to be done for
>>>>>>>> kubernetes pods when you mention sip ingress
>>>>>>>>
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>>
>>>>>>>>
>>>>>>>> Pavithra
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On Tue, Aug 25, 2020, 9:32 PM Sergey Safarov <s.safarov at gmail.com>
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>> Lot of issues with static IP in Kubernetes.
>>>>>>>>>
>>>>>>>>> Looks as need deploy "sip ingress" like "HTTP/HTTPS ingress" and
>>>>>>>>> then route calls to pods.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Tue, Aug 25, 2020 at 4:40 PM Pavithra Mohanraja <
>>>>>>>>> pavimohan3004 at gmail.com> wrote:
>>>>>>>>>
>>>>>>>>>> Hi,
>>>>>>>>>>
>>>>>>>>>> I am configuring kamailio IMS as kubernetes pods .
>>>>>>>>>> so each component will be configured as separate pod .
>>>>>>>>>> In order to establish a connection between pods , I am
>>>>>>>>>> configuring bind9 dns server in pcscf pod itself. Communication is
>>>>>>>>>> happening via Pod IP address.
>>>>>>>>>>
>>>>>>>>>> Is there any possibility to have the communication using cluster
>>>>>>>>>> IP . If anybody is aware of kubernetes, Please help me in this regard.
>>>>>>>>>>
>>>>>>>>>> I have my /etc/resolv.conf file in pods with
>>>>>>>>>> nameserver <clusterIP>
>>>>>>>>>> search <cluster-dns-domain-name>
>>>>>>>>>>
>>>>>>>>>> Please help.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Thanks,
>>>>>>>>>> Pavithra
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> _______________________________________________
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Kamailio (SER) - Users Mailing List
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> sr-users at lists.kamailio.org
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> _______________________________________________
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Kamailio (SER) - Users Mailing List
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> sr-users at lists.kamailio.org
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>>
>>>>>>>>
>>>>>>>> Kamailio (SER) - Users Mailing List
>>>>>>>>
>>>>>>>>
>>>>>>>> sr-users at lists.kamailio.org
>>>>>>>>
>>>>>>>>
>>>>>>>> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>>
>>>>>>>
>>>>>>> Kamailio (SER) - Users Mailing List
>>>>>>>
>>>>>>>
>>>>>>> sr-users at lists.kamailio.org
>>>>>>>
>>>>>>>
>>>>>>> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>>
>>>>>> Kamailio (SER) - Users Mailing List
>>>>>>
>>>>>> sr-users at lists.kamailio.org
>>>>>>
>>>>>> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
>>>>>>
>>>>>> --
>>>>> Regards,
>>>>>
>>>>> David Villasmil
>>>>> email: david.villasmil.work at gmail.com
>>>>> phone: +34669448337
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>>
>>>>>
>>>>> Kamailio (SER) - Users Mailing List
>>>>>
>>>>>
>>>>> sr-users at lists.kamailio.org
>>>>>
>>>>>
>>>>> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>
>>
>
> --
Regards,

David Villasmil
email: david.villasmil.work at gmail.com
phone: +34669448337
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.kamailio.org/pipermail/sr-users/attachments/20200827/1e5f8473/attachment.htm>


More information about the sr-users mailing list