CentOS 7.2安裝Kubernetes 1.03

CentOS 已經把 Kubernetes 加入官方源，所以現在安裝Kubernetes已經方便很多。

各組件版本如下：

Kubernetes-1.03
docker-1.8.2
flannel-0.5.3
etcd-2.1.1

Kubernetes部署環境角色如下：
CentOS 7.2 64位系統，3台虛擬機：

master：192.168.32.15
minion1:192.168.32.16
minion2:192.168.32.17

1. 預處理
每台機器禁用iptables 避免和docker 的iptables沖突：

systemctl stop firewalld
systemctl disable firewalld

禁用selinux：

vim /etc/selinux/config
#SELINUX=enforcing
SELINUX=disabled

在2個minions機器安裝docker：

yum -y install docker
yum -y update
reboot

CentOS系統，使用devicemapper作為存儲後端，初始安裝docker 會使用loopback, 導致docker啟動報錯，需要update之後再啟動。

2. master結點的安裝與配置
安裝etcd與kubernetes-master：

yum -y install etcd kubernetes-master

修改etcd配置文件：

# egrep -v “^#” /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://192.168.32.15:2379"

修改kube-master配置文件：

# egrep -v ‘^#’ /etc/kubernetes/apiserver | grep -v ‘^$’
KUBE_API_ADDRESS="--address=0.0.0.0"
KUBE_ETCD_SERVERS="--etcd_servers=http://192.168.32.15:2379"
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=""

# egrep -v ‘^#’ /etc/kubernetes/controller-manager |grep -v ‘^$’
KUBE_CONTROLLER_MANAGER_ARGS="--node-monitor-grace-period=10s --pod-eviction-timeout=10s"

[root@localhost ~]# egrep -v ‘^#’ /etc/kubernetes/config | egrep -v ‘^$’
KUBE_LOGTOSTDERR="--logtostderr=true"
KUBE_LOG_LEVEL="--v=0"
KUBE_ALLOW_PRIV="--allow_privileged=false"
KUBE_MASTER="--master=http://192.168.32.15:8080"

啟動服務：

systemctl enable etcd kube-apiserver kube-scheduler kube-controller-manager
systemctl start etcd kube-apiserver kube-scheduler kube-controller-manager

定義flannel網絡配置到etcd,這個配置會推送到各個minions的flannel服務上：

etcdctl mk /coreos.com/network/config '{"Network":"172.17.0.0/16"}'

3. minion結點的安裝與配置

yum -y install kubernetes-node flannel

修改kube-node和flannel配置文件：

# egrep -v ‘^#’ /etc/kubernetes/config | grep -v ‘^$’
KUBE_LOGTOSTDERR="--logtostderr=true"
KUBE_LOG_LEVEL="--v=0"
KUBE_ALLOW_PRIV="--allow_privileged=false"
KUBE_MASTER="--master=http://192.168.32.15:8080"

# egrep -v ‘^#’ /etc/kubernetes/kubelet | grep -v ‘^$’
KUBELET_ADDRESS="--address=127.0.0.1"
KUBELET_HOSTNAME="--hostname_override=192.168.32.16"
KUBELET_API_SERVER="--api_servers=http://192.168.32.15:8080"
KUBELET_ARGS="--pod-infra-container-image=kubernetes/pause"

為etcd服務配置flannel，修改配置文件 /etc/sysconfig/flanneld：

FLANNEL_ETCD="http://192.168.32.15:2379"
FLANNEL_ETCD_KEY="/coreos.com/network"

啟動服務：

systemctl enable flanenld kubelet kube-proxy
systemctl restart flanneld docker
systemctl start kubelet kube-proxy

在每個minions可以看到2塊網卡：docker0和flannel0，這2塊網卡的ip在不同的機器ip地址不同：

#minion1
4: flannel0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1472 qdisc pfifo_fast state UNKNOWN qlen 500
    link/none
    inet 172.17.98.0/16 scope global flannel0
       valid_lft forever preferred_lft forever
5: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN
    link/ether 02:42:9a:01:ca:99 brd ff:ff:ff:ff:ff:ff
    inet 172.17.98.1/24 scope global docker0
       valid_lft forever preferred_lft forever
 
#minion2
4: flannel0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1472 qdisc pfifo_fast state UNKNOWN qlen 500
    link/none
    inet 172.17.67.0/16 scope global flannel0
       valid_lft forever preferred_lft forever
5: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN
    link/ether 02:42:25:be:ba:64 brd ff:ff:ff:ff:ff:ff
    inet 172.17.67.1/24 scope global docker0
       valid_lft forever preferred_lft forever

4. 檢查狀態
登陸master，確認minions的狀態：

[root@master ~]# kubectl get nodes
NAME            LABELS                                 STATUS
192.168.32.16   kubernetes.io/hostname=192.168.32.16   Ready
192.168.32.17   kubernetes.io/hostname=192.168.32.17   Ready

kubernetes的集群就配置完成，下面就是搞pod了，後續會繼續試驗。