[SR-Users] Kamailio IMS as kubernetes pods

Thu Aug 27 20:25:11 CEST 2020

Interesting! I’ll be testing that very soon! Many thanks!!

On Thu, 27 Aug 2020 at 14:53, Abdirahman A. Osman <abdirahman.osm at gmail.com>
wrote:

> Hi David,
>
> Yes that is right, so when you set to ClusterIP:none, it turns the
> services into a headless services. and the DNS will resolve to a single
> POD, instead of a group of PODs, and you can reach every POD through the
> DNS. IPs may change but the DNS will stay fixed when you use Statefullset,
> as you need a fixed DNS name for the pod. If you  use Deployment you get a
> randomly generated name, which is not what you want.
>
>
> Abdirahman
>
>
>
> On Thu, 27 Aug 2020 at 08:06, David Villasmil <
> david.villasmil.work at gmail.com> wrote:
>
>> 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
>>
>>
>>
>
> --
Regards,

David Villasmil
email: david.villasmil.work at gmail.com
phone: +34669448337
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