Re: [SR-Users] Kamailio IMS as kubernetes pods

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(a)gmail.com&gt; 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(a)gmail.com&gt; 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(a)gmail.com&gt; 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(a)gmail.com&gt; 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(a)gmail.com&gt; 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 &lt;s.safarov(a)gmail.com&gt; >>>>> 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(a)gmail.com&gt; 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(a)gmail.com&gt; 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(a)gmail.com&gt; 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(a)lists.kamailio.org >>>>>>>>> >>>>>>>>> >>>>>>>>> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> >>>>>>>> >>>>>>>> Kamailio (SER) - Users Mailing List >>>>>>>> >>>>>>>> >>>>>>>> sr-users(a)lists.kamailio.org >>>>>>>> >>>>>>>> >>>>>>>> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> _______________________________________________ >>>>>>> >>>>>>> >>>>>>> Kamailio (SER) - Users Mailing List >>>>>>> >>>>>>> >>>>>>> sr-users(a)lists.kamailio.org >>>>>>> >>>>>>> >>>>>>> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users >>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> >>>>>> >>>>>> Kamailio (SER) - Users Mailing List >>>>>> >>>>>> >>>>>> sr-users(a)lists.kamailio.org >>>>>> >>>>>> >>>>>> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users >>>>>> >>>>>> >>>>>> >>>>> >>>>> _______________________________________________ >>>>> >>>>> Kamailio (SER) - Users Mailing List >>>>> >>>>> sr-users(a)lists.kamailio.org >>>>> >>>>> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users >>>>> >>>>> -- >>>> Regards, >>>> >>>> David Villasmil >>>> email: david.villasmil.work(a)gmail.com >>>> phone: +34669448337 >>>> >>>> >>>> _______________________________________________ >>>> >>>> >>>> Kamailio (SER) - Users Mailing List >>>> >>>> >>>> sr-users(a)lists.kamailio.org >>>> >>>> >>>> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users >>>> >>>> >>>> >>> >>> >> >> > > --