Install K8s on CentOS

install_kubernetes_on_CentOS

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#0. Hosts in cluster
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#yum install -y net-tools nano wget

#192.168.70.141 k8s-master
#192.168.70.142 k8s-node

#Edit hosts file on all hosts (master,node)
cat <<EOF >> /etc/hosts
192.168.70.141 k8s-master
192.168.70.142 k8s-node
EOF


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#1. Configuration (master,node)
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setenforce 0
systemctl stop firewalld
systemctl disable firewalld

yum install -y ntp
systemctl start ntpd
systemctl enable ntpd
systemctl status ntpd

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#3. Add repo to all hosts (master,node)
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cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg
       https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF

#NOTE: IF YOU WANT TO INSTALL LATEST VERSION (CURRENTLY 1.7.3)
#FOLLOW THIS GUIDE: https://gist.github.com/davistran86/c85d865abbf15e4f51365bee1a30c53e

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#4. Install 
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#STEP 1 (master,node):
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yum -y install --enablerepo=kubernetes kubernetes etcd flannel
#K8S 1.7.3: yum -y install --enablerepo=virt7-container-common-candidate kubernetes etcd flannel
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#STEP 2 (master,node):
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nano /etc/kubernetes/config
 
# Comma separated list of nodes running etcd cluster
KUBE_ETCD_SERVERS="--etcd-servers=http://192.168.70.141:2379"
# Logging will be stored in system journal
KUBE_LOGTOSTDERR="--logtostderr=true"
# Journal message level, 0 is debug
KUBE_LOG_LEVEL="--v=0"
# Should this cluster be allowed to run privileged docker containers
KUBE_ALLOW_PRIV="--allow-privileged=false"
# Api-server endpoint used in scheduler and controller-manager
KUBE_MASTER="--master=http://192.168.70.141:8080"

#copy to node: scp /etc/kubernetes/config root@192.168.70.142:/etc/kubernetes/config
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#STEP 3 (master):
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nano /etc/etcd/etcd.conf

#[member]
ETCD_NAME=default
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
 
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"
#[cluster]
ETCD_ADVERTISE_CLIENT_URLS="http://0.0.0.0:2379"
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#STEP 4 (master):
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wget https://raw.githubusercontent.com/kubernetes/kubernetes/master/cluster/saltbase/salt/generate-cert/make-ca-cert.sh
#edit cert_group in make-ca-cert.sh as below:
nano make-ca-certh.sh

cert_group=${CERT_GROUP:-kube}
#RUN
bash make-ca-cert.sh "192.168.70.141" "IP:192.168.70.141,IP:10.254.0.1,DNS:kubernetes,DNS:kubernetes.default,DNS:kubernetes.default.svc,DNS:kubernetes.default.svc.cluster.local"
#10.254.0.1 is ip of K8s service
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#STEP 5 (master):
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nano /etc/kubernetes/apiserver

# Bind kube API server to this IP
KUBE_API_ADDRESS="--address=0.0.0.0"
# Port that kube api server listens to.
KUBE_API_PORT="--port=8080"
# Port kubelet listen on
KUBELET_PORT="--kubelet-port=10250"
# Address range to use for services(Work unit of Kubernetes)
KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16"
# default admission control policies
#KUBE_ADMISSION_CONTROL="--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ServiceAccount,ResourceQuota"
# Add your own!
KUBE_API_ARGS="--client-ca-file=/srv/kubernetes/ca.crt --tls-cert-file=/srv/kubernetes/server.cert --tls-private-key-file=/srv/kubernetes/server.key"
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#STEP 6 (master):
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nano /etc/kubernetes/controller-manager

# Add your own!
KUBE_CONTROLLER_MANAGER_ARGS="--root-ca-file=/srv/kubernetes/ca.crt --service-account-private-key-file=/srv/kubernetes/server.key"
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#STEP 7 (nodes):
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nano /etc/kubernetes/kubelet

# kubelet bind ip address(Provide private ip of minion)
KUBELET_ADDRESS="--address=0.0.0.0"
# port on which kubelet listen
KUBELET_PORT="--port=10250"
# leave this blank to use the hostname of server
KUBELET_HOSTNAME="--hostname-override=k8s-node1"
# Location of the api-server
KUBELET_API_SERVER="--api-servers=http://k8s-master:8080"
# Add your own!
KUBELET_ARGS=""
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#STEP 8 (master):
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systemctl start etcd
etcdctl mkdir /kube-centos/network
etcdctl mk /kube-centos/network/config "{ \"Network\": \"172.30.0.0/16\", \"SubnetLen\": 24, \"Backend\": { \"Type\": \"vxlan\" } }"
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#STEP 9 (master,node):
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nano /etc/sysconfig/flanneld

# etcd URL location.  Point this to the server where etcd runs
FLANNEL_ETCD="http://192.168.70.141:2379"
# etcd config key.  This is the configuration key that flannel queries
# For address range assignment
FLANNEL_ETCD_PREFIX="/kube-centos/network"
# Any additional options that you want to pass
FLANNEL_OPTIONS=""

#copy to node: scp /etc/sysconfig/flanneld root@192.168.70.142:/etc/sysconfig/flanneld
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#STEP 10 (master):
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for SERVICES in etcd kube-apiserver kube-controller-manager kube-scheduler flanneld; do
    systemctl restart $SERVICES
    systemctl enable $SERVICES
    systemctl status $SERVICES
done
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#STEP 11 (nodes):
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for SERVICES in kube-proxy kubelet flanneld docker; do
    systemctl restart $SERVICES
    systemctl enable $SERVICES
    systemctl status $SERVICES
done

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#STEP 12 (master,nodes):
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kubectl config set-cluster default-cluster --server=http://k8s-master:8080
kubectl config set-context default-context --cluster=default-cluster --user=default-admin
kubectl config use-context default-context

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#TODO: Install DNS and Dashboard
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