k8s_nginx_lb

From k8s deployment a loadbalance nginx cluster.

k8s_env,master_count:1, pod_count:2.

• master_configuration:

# yum -y install etcd kubernetes-master

/etc/etcd/etcd.conf
ETCD_NAME=default
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"
ETCD_ADVERTISE_CLIENT_URLS="http://localhost:2379"

/etc/kubernetes/apiserver
KUBE_API_ADDRESS="--insecure-bind-address=0.0.0.0"
KUBE_API_PORT="--port=8080"
KUBELET_PORT="--kubelet-port=10250"
KUBE_ETCD_SERVERS="--etcd-servers=http://127.0.0.1:2379"
KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16"
KUBE_ADMISSION_CONTROL="--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ResourceQuota"
KUBE_API_ARGS=""

run etcd、kube-apiserver、kube-controller-manager、kube-scheduler service，and change to enabled.

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

define flannel network

# etcdctl mk /atomic.io/network/config '{"Network":"172.17.0.0/16"}'

• node_configuration:

# yum -y install flannel kubernetes-node

/etc/sysconfig/flanneld
FLANNEL_ETCD="http://<master_ip>:2379"
FLANNEL_ETCD_KEY="/atomic.io/network"

/etc/kubernetes/config
KUBE_LOGTOSTDERR="--logtostderr=true"
KUBE_LOG_LEVEL="--v=0"
KUBE_ALLOW_PRIV="--allow-privileged=false"
KUBE_MASTER="--master=http://<master_ip>:8080"

/etc/kubernetes/kubelet
　　node1:
KUBELET_ADDRESS="--address=0.0.0.0"
KUBELET_PORT="--port=10250"
KUBELET_HOSTNAME="--hostname-override=<node1_ip>"
KUBELET_API_SERVER="--api-servers=http://<master_ip>:8080"
KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=registry.access.redhat.com/rhel7/pod-infrastructure:latest"
KUBELET_ARGS=""
　　node2:
KUBELET_ADDRESS="--address=0.0.0.0"
KUBELET_PORT="--port=10250"
KUBELET_HOSTNAME="--hostname-override=<node2_ip>"
KUBELET_API_SERVER="--api-servers=http://<master_ip>:8080"
KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=registry.access.redhat.com/rhel7/pod-infrastructure:latest"
KUBELET_ARGS=""

all node run kube-proxy,kubelet,docker,flanneld service，and change to enabled.

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

deployment nginx cluster

• create pod

# kubectl create -f nginx-rc.yaml

• create service

# kubectl create -f nginx-service-nodeport.yaml

• view pod state

# kubectl get pods
NAME                     READY     STATUS    RESTARTS   AGE
nginx-controller-534rm   1/1       Running   1          3h
nginx-controller-c3fzv   1/1       Running   1          3h

• view pod desc

# kubectl describe pod nginx-controller-534rm
...

• view service state

# kubectl get service
NAME                     CLUSTER-IP     EXTERNAL-IP   PORT(S)          AGE
kubernetes               10.254.0.1     <none>        443/TCP          3h
nginx-service-nodeport   10.254.2.144   <nodes>       8000:32266/TCP   3h

• view service desc

# kubectl describe service nginx-service-nodeport
...

• We can use <node_ip>:port access nginx cluster , and achieve loadbalance:
• In this test. node_ip is node1_ip or node2_ip , port is 32266(by nodePort).
• By service_nodeport achieve nginx loadbalance cluster.
• By rc achieve pod dynamic stretching.