Kubernetes Cetos 7 minimal Preinstallation (VMWare Workstation 15)
Step1: Download centos 7 minimal iso image and install it via vmware workstation 15
tbd
Step2: Configure static network interface
Edit -> Virtual Network Editor -> configure as following and -> NAT Settings... -> Start vm
Get Mac Adress of your instance by using:
cat /sys/class/net/{your network insterface}/address-> 00:0c:29:71:91:df
start with editing “/etc/sysconfig/network-scripts/ifcfg-ens33″
vi /etc/sysconfig/network-scripts/ifcfg-ens33
add following configuration:
HWADDR=00:0C:29:71:91:DF TYPE=Ethernet BOOTPROTO=static DEFROUTE=yes PEERDNS=yes PEERROUTES=yes IPV4_FAILURE_FATAL=no IPADDR=172:16.0.11NETMASK=255.255.255.0 GATEWAY=172.16.0.2 IPV6INIT=yes IPV6_AUTOCONF=yes IPV6_DEFROUTE=yes IPV6_PEERDNS=yes IPV6_PEERROUTES=yes IPV6_FAILURE_FATAL=no NAME=ens33 DEVICE=ens33 UUID=ea68db6e-461e-427d-b9a8-bfcf6e1a4fc6 ONBOOT=yes
Configure default gateway
vi /etc/sysconfig/network
Add following line:
NETWORKING=yes HOSTNAME=k8smaster GATEWAY=172.16.0.2
Configure DNS Server
vi /etc/resolv.conf
Add following line:
nameserver 8.8.8.8 nameserver 8.8.4.4
Restart network service:
systemctl restart network
ping www.sohu.com
If it works, turn down vm -> shutdown now
Clone a second machine
set the right IPADDR, HWADDR and UUID for network interface then hostname for default gateway
how get UUID of this machine:
uuidgen ifcfg-ens33 # or # echo UUID=$(uuidgen ifcfg-ens33) >> ifcfg-ens33 # then delete the original one
Now you have 3 virtual machines with different ips
For installation of common software like docker and some setting for preinstallation, I wrote a ansible script see my github (tbd)
The rest see:
https://www.digitalocean.com/community/tutorials/how-to-create-a-kubernetes-1-10-cluster-using-kubeadm-on-centos-7
Start master node with kubeadm init
kubeadm init --ignore-preflight-errors all --kubernetes-version=v1.11.1 --pod-network-cidr=10.244.0.0/16 --service-cidr=10.96.0.0/12
then wait.... your os will pull docker image from docker hub
Your Kubernetes master has initialized successfully! To start using your cluster, you need to run the following as a regular user: mkdir -p $HOME/.kube sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config sudo chown $(id -u):$(id -g) $HOME/.kube/config You should now deploy a pod network to the cluster. Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at: https://kubernetes.io/docs/concepts/cluster-administration/addons/ You can now join any number of machines by running the following on each node as root: kubeadm join 172.16.0.11:6443 --token s97rc5.oio179xrb0fbxrg2 --discovery-token-ca-cert-hash sha256:ade669b38cf81989baf62fae57cdc50cf8aba5db429841e33e6c090aded2730e
run
docker images
[[email protected] ~]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE k8s.gcr.io/kube-proxy-amd64 v1.11.1 d5c25579d0ff 5 months ago 97.8MB k8s.gcr.io/kube-scheduler-amd64 v1.11.1 272b3a60cd68 5 months ago 56.8MB k8s.gcr.io/kube-apiserver-amd64 v1.11.1 816332bd9d11 5 months ago 187MB k8s.gcr.io/kube-controller-manager-amd64 v1.11.1 52096ee87d0e 5 months ago 155MB k8s.gcr.io/coredns 1.1.3 b3b94275d97c 7 months ago 45.6MB k8s.gcr.io/etcd-amd64 3.2.18 b8df3b177be2 8 months ago 219MB k8s.gcr.io/pause 3.1 da86e6ba6ca1 12 months ago 742kB [[email protected] ~]#
validate your installation:
[[email protected] ~]# kubectl get nodes NAME STATUS ROLES AGE VERSION k8smaster NotReady master 18m v1.11.1 [[email protected] ~]#
status -> NotReady because you need a network addon like flannel
Install flannel
kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
then you will see:
[email protected] ~]# kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml clusterrole.rbac.authorization.k8s.io/flannel created clusterrolebinding.rbac.authorization.k8s.io/flannel created serviceaccount/flannel created configmap/kube-flannel-cfg created daemonset.extensions/kube-flannel-ds-amd64 created daemonset.extensions/kube-flannel-ds-arm64 created daemonset.extensions/kube-flannel-ds-arm created daemonset.extensions/kube-flannel-ds-ppc64le created daemonset.extensions/kube-flannel-ds-s390x created
Validate pods: kubectl get pods -n kube-system
-n -> namespace
[[email protected] ~]# kubectl get pods -n kube-system NAME READY STATUS RESTARTS AGE coredns-78fcdf6894-5v9g9 1/1 Running 0 27m coredns-78fcdf6894-lpwfw 1/1 Running 0 27m etcd-k8smaster 1/1 Running 0 1m kube-apiserver-k8smaster 1/1 Running 0 1m kube-controller-manager-k8smaster 1/1 Running 0 1m kube-flannel-ds-amd64-n5j7l 1/1 Running 0 1m kube-proxy-rjssr 1/1 Running 0 27m kube-scheduler-k8smaster 1/1 Running 0 1m
Now adding two worker nodes to cluster
on k8snode1
kubeadm join --ignore-preflight-errors all 172.16.0.11:6443 --token s97rc5.oio179xrb0fbxrg2 --discovery-token-ca-cert-hash sha256:ade669b38cf81989baf62fae57cdc50cf8aba5db429841e33e6c090aded2730e
Validating on master node with:
[[email protected] ~]# kubectl get pods -n kube-system -o wide NAME READY STATUS RESTARTS AGE IP NODE coredns-78fcdf6894-5v9g9 1/1 Running 0 40m 10.244.0.2 k8smaster coredns-78fcdf6894-lpwfw 1/1 Running 0 40m 10.244.0.3 k8smaster etcd-k8smaster 1/1 Running 0 14m 172.16.0.11 k8smaster kube-apiserver-k8smaster 1/1 Running 0 14m 172.16.0.11 k8smaster kube-controller-manager-k8smaster 1/1 Running 0 14m 172.16.0.11 k8smaster kube-flannel-ds-amd64-hs6b9 1/1 Running 0 3m 172.16.0.12 k8snode1 kube-flannel-ds-amd64-n5j7l 1/1 Running 0 14m 172.16.0.11 k8smaster kube-proxy-8x5p6 1/1 Running 0 3m 172.16.0.12 k8snode1 kube-proxy-rjssr 1/1 Running 0 40m 172.16.0.11 k8smaster kube-scheduler-k8smaster 1/1 Running 0 14m 172.16.0.11 k8smaster
The same on k8snode2...
[[email protected] ~]# kubectl get nodes NAME STATUS ROLES AGE VERSION k8smaster Ready master 43m v1.11.1 k8snode1 Ready <none> 6m v1.11.1 k8snode2 Ready <none> 40s v1.11.1
[[email protected] ~]# kubectl get pods -n kube-system -o wide NAME READY STATUS RESTARTS AGE IP NODE coredns-78fcdf6894-5v9g9 1/1 Running 0 44m 10.244.0.2 k8smaster coredns-78fcdf6894-lpwfw 1/1 Running 0 44m 10.244.0.3 k8smaster etcd-k8smaster 1/1 Running 0 17m 172.16.0.11 k8smaster kube-apiserver-k8smaster 1/1 Running 0 17m 172.16.0.11 k8smaster kube-controller-manager-k8smaster 1/1 Running 0 17m 172.16.0.11 k8smaster kube-flannel-ds-amd64-8gpzz 1/1 Running 0 1m 172.16.0.13 k8snode2 kube-flannel-ds-amd64-hs6b9 1/1 Running 0 7m 172.16.0.12 k8snode1 kube-flannel-ds-amd64-n5j7l 1/1 Running 0 17m 172.16.0.11 k8smaster kube-proxy-8x5p6 1/1 Running 0 7m 172.16.0.12 k8snode1 kube-proxy-jkpgf 1/1 Running 0 1m 172.16.0.13 k8snode2 kube-proxy-rjssr 1/1 Running 0 44m 172.16.0.11 k8smaster kube-scheduler-k8smaster 1/1 Running 0 17m 172.16.0.11 k8smaster
Done :-)