Kubernetes simple (1 Master y 1 Minion)

Escenario

Infraestructura Kubernetes HA

Nombre	Función	IP externa	IP interna
Morrigan	Kubernetes master 1	172.22.205.240	10.0.0.43
Artio	Kubernetes minion 1	172.22.205.242	10.0.0.45

Esquema de funcionamiento

Simple

Configuración previa

Configuración de nombres

echo "10.0.0.43  morrigan
10.0.0.45    artio" >> /etc/hosts

Repositorios (Masters y minions)

sudo yum install epel-release

sudo nano /etc/yum.repos.d/virt7-docker-common-release.repo
[virt7-docker-common-release]
name=virt7-docker-common-release
baseurl=http://cbs.centos.org/repos/virt7-docker-common-release/x86_64/os/
gpgcheck=0


sudo yum -y install --enablerepo=virt7-docker-common-release kubernetes

Instalación

Master
```
yum -y install etcd kubernetes
```
Minion
```
yum -y install flannel kubernetes
```

Configuración

Configuración Kubernetes (Master y minion)

Editamos /etc/kubernetes/config

KUBE_ETCD_SERVERS="--etcd-servers=http://morrigan:2379"
KUBE_LOGTOSTDERR="--logtostderr=true"
KUBE_LOG_LEVEL="--v=0"
KUBE_ALLOW_PRIV="--allow-privileged=true"
KUBE_MASTER="--master=http://morrigan:8080"

Configuración Apiserver (Master)

Editamos /etc/kubernetes/apiserver

KUBE_API_ADDRESS="--address=0.0.0.0"
KUBE_API_PORT="--port=8080"
KUBE_MASTER="--master=http://morrigan:8080"
KUBELET_PORT="--kubelet-port=10250"
KUBE_ETCD_SERVERS="--etcd-servers=http://morrigan:2379"
KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16"
KUBE_ADMISSION_CONTROL="--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ServiceAccount,ResourceQuota"
KUBE_API_ARGS=""

Habilitamos y ejecutamos las siguientes unidades

for SERVICES in etcd kube-apiserver kube-controller-manager kube-scheduler; do 
    systemctl restart $SERVICES
    systemctl enable $SERVICES
    systemctl status $SERVICES 
done

Configuración Kubelet (Minion)

Editamos /etc/kubernetes/kubelet

KUBELET_ADDRESS="--address=0.0.0.0"
KUBELET_PORT="--port=10250"
KUBELET_HOSTNAME="--hostname-override=artio"
KUBELET_API_SERVER="--api-servers=http://morrigan:8080"
KUBELET_ARGS=""

Habilitamos y ejecutamos las siguientes unidades

for SERVICES in kube-proxy kubelet docker; do 
    systemctl restart $SERVICES
    systemctl enable $SERVICES
    systemctl status $SERVICES 
done

Podemos comprobar el estado del minion Artio con

kubectl get nodes

NAME            LABELS                                  STATUS    AGE
artio     kubernetes.io/hostname=artio                  Ready     1m