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I have a K8s cluster installed in several RHEL 7.2 VMs. Seems that the installation form yum repository comes without addons.

Currently I am facing the following problem almost with any service I am trying to deploy: Jenkins, Kube-ui, influxdb-grafana Endpoints IPs are not in the range that is defined for Flannel and obviously the services are not available.

Any ideas on how to debug\resolve the problem?

System details:

# lsb_release -i -r
Distributor ID: RedHatEnterpriseServer
Release:        7.2

Packages installed:

kubernetes.x86_64               1.2.0-0.9.alpha1.gitb57e8bd.el7
etcd.x86_64                     2.2.5-1.el7
flannel.x86_64                  0.5.3-9.el7
docker.x86_64                   1.9.1-25.el7.centos

ETCD network configuration

# etcdctl get /atomic.io/network/config
{"Network":"10.0.0.0/16"}

Service gets proper IP but wrong Endpoints

# kubectl describe svc jenkinsmaster
Name:                   jenkinsmaster
Namespace:              default
Labels:                 kubernetes.io/cluster-service=true,kubernetes.io/name=JenkinsMaster
Selector:               name=jenkinsmaster
Type:                   NodePort
IP:                     10.254.113.89
Port:                   http    8080/TCP
NodePort:               http    30996/TCP
Endpoints:              172.17.0.2:8080
Port:                   slave   50000/TCP
NodePort:               slave   31412/TCP
Endpoints:              172.17.0.2:50000
Session Affinity:       None
No events.

Thank you.

Daniel Rogatchevsky
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2 Answers2

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I think the flannel network subnet and the kubernetes internal network subnet seems to be conflicting here.

With the amount of information as I see now all I can say is that there is a conflict here. To verify that flannel is working just start contianer in two different machines connected with flannel and see if they can talk and what IP address they get. If they are being assigned IP of range 10.0.0.0/16 and they can talk then flannel is doing good. And something is wrong with the integration with kubernetes.

If you are not getting the IP addresses of some other range flannel is not doing good.

surajd
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kubernetes 1.12...docker 1.9... They are ancient version now. So you don't have CNI or kubeadm. I can barely remember how to setup a kubernetes cluster with flannel that time.

Anyway, you need to know Endpoint IP is same as target Pod IP, that is IP of docker container. So your docker container IP is not the same range as your flannel IP, and 172.17.0.x is the default docker IP range. So I think you need to change docker start parameter like --bip=${FLANNEL_SUBNET} --mtu=${FLANNEL_MTU}, you can use 10.0.0.0/16 as FLANNEL_SUBNET is you want a basic setup.

Crazykev
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