Kubernetes叢集安裝與配置
注：本文系統環境為centos7，master：10.1.1.1，node1：10.1.1.2
etcd安裝與配置
使用yum install etcd或者官網下載etcd進行安裝，copy etcd和etcdctl到/usr/bin目錄下
設定systemd服務檔案：/usr/lib/systemd/system/etcd.service
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target
[Service]
Type=notify
WorkingDirectory 服務檔案指定配置檔案為/etc/etcd/etcd.conf，ExecStart為配置的啟動命令，其中的變數資訊通過配置檔案進行獲取，配置檔案配置如下：
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://10.1.1.1:2379"配置完成後，通過systemctl start命令啟動etcd服務。
Flanneld網路配置與啟動
flannel採用覆蓋網路(overlay network)模型來完成對網路的打通，需要在每臺node上都安裝flannel。
安裝：
yum install flannle進行安裝 配置： 編輯
/usr/lib/systemd/system/flanneld.service
[Unit]
Description=Flanneld overlay address etcd agent
After=network.target
After=network-online.target
Wants=network-online.target
After=etcd.service
Before=docker.service
[Service]
Type=notify
EnvironmentFile=/etc/sysconfig/flanneld
EnvironmentFile=-/etc/sysconfig/docker-network
ExecStart=/usr/bin/flanneld-start $FLANNEL_OPTIONS
ExecStartPost=/usr/libexec/flannel/mk-docker-opts.sh -k DOCKER_NETWORK_OPTIONS -d /run/flannel/docker
Restart=on-failure
[Install]
WantedBy=multi-user.target
RequiredBy=docker.service配置啟動引數： 編輯/etc/sysconfig/flanneld
# Flanneld configuration options
# etcd url location. Point this to the server where etcd runs
FLANNEL_ETCD_ENDPOINTS="http://10.1.1.1:2379"
# etcd config key. This is the configuration key that flannel queries
# For address range assignment
FLANNEL_ETCD_PREFIX="/coreos.com/network"
# Any additional options that you want to pass
#FLANNEL_OPTIONS=""啟動前，需要在etcd中新增一條網路配置記錄，用於flanneld分配給每個docker的虛擬ip地址段。
etcdctl set /coreos.com/network/config '{"Network":"172.17.0.0/16"}'
由於flannel將覆蓋docker0網橋，需先停止docker服務。
使用systemctl啟動flanneld。
設定docker0網橋的ip地址，執行
/usr/libexec/flannel/mk-docker-opts.sh -i
source /run/flannel/subnet.env
ifconfig docker0 ${FLANNEL_SUBNET}使用ip addr確認docker0是否屬於flannel0的子網。
重新啟動docker服務。
安裝Kubernetes
使用yum install kubernetes命令對kubernetes的一系列檔案進行安裝，包括kube-apiserver、kube-controller-manager、kube-scheduler、kubelet、kube-proxy等服務。
其中master節點安裝部署etcd、kube-apiserver、kube-controller-manager、kube-scheduler服務；
node節點安裝kubelet、kube-proxy服務。
master節點的配置
kube-apiserver服務配置
將安裝的kube-apiserver複製到/usr/bin目錄下，編輯systemd服務檔案/usr/lib/systemd/system/kube-apiserver.service
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target
After=etcd.service
[Service]
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/apiserver
User=kube
ExecStart=/usr/bin/kube-apiserver \
$KUBE_LOGTOSTDERR \
$KUBE_LOG_LEVEL \
$KUBE_ETCD_SERVERS \
$KUBE_API_ADDRESS \
$KUBE_API_PORT \
$KUBELET_PORT \
$KUBE_ALLOW_PRIV \
$KUBE_SERVICE_ADDRESSES \
$KUBE_ADMISSION_CONTROL \
$KUBE_API_ARGS
Restart=on-failure
Type=notify
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target其中變數指定內容均在/etc/kubernetes/config以及/etc/kubernetes/apiserver檔案中定義。
vim /etc/kubernetes/config：
# 設定false表示將日誌寫入檔案，不寫入stderr
KUBE_LOGTOSTDERR="--logtostderr=true"
# 日誌級別，0是debug模式
KUBE_LOG_LEVEL="--v=0"
# 該叢集是否可用於執行私有容器
KUBE_ALLOW_PRIV="--allow_privileged=false"
# controller-manager, scheduler和proxy通過該變數找到apiserver
KUBE_MASTER="--master=http://127.0.0.1:8080"vim /etc/kubernetes/apiserver：
KUBE_API_ADDRESS="--address=0.0.0.0"
# apiserver監聽的埠號
# KUBE_API_PORT="--port=8080"
# kubelet埠號
# KUBELET_PORT="--kubelet_port=10250"
# 配置etcd服務，叢集可用逗號分隔
KUBE_ETCD_SERVERS="--etcd_servers=http://10.1.1.1:2379"
# 叢集中Service的虛擬IP地址段範圍
KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16"
# 叢集的准入控制設定，各控制模組以外掛的形式依次生效
KUBE_ADMISSION_CONTROL="--admission_control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ResourceQuota"
# Add your own!
KUBE_API_ARGS=""kube-controller-manager服務配置
配置kube-controller-manager.service：
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
[Service]
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/controller-manager
User=kube
ExecStart=/usr/bin/kube-controller-manager \
$KUBE_LOGTOSTDERR \
$KUBE_LOG_LEVEL \
$KUBE_MASTER \
$KUBE_CONTROLLER_MANAGER_ARGS
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.targetvim /etc/kubernetes/controller-manager
KUBE_CONTROLLER_MANAGER_ARGS="--node-monitor-grace-period=10s --pod-eviction-timeout=10s"kube-scheduler配置
配置kube-scheduler.service：
[Unit]
Description=Kubernetes Scheduler Plugin
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
[Service]
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/scheduler
User=kube
ExecStart=/usr/bin/kube-scheduler \
$KUBE_LOGTOSTDERR \
$KUBE_LOG_LEVEL \
$KUBE_MASTER \
$KUBE_SCHEDULER_ARGS
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.targetvim /etc/kubernetes/scheduler
KUBE_SCHEDULER_ARGS=""node節點配置
kubelet安裝和配置
安裝： 使用yum install kubernetes全部安裝了
配置service檔案： 編輯/usr/lib/systemd/system/kubelet.service
[Unit]
Description=Kubernetes Kubelet Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=docker.service
Requires=docker.service
[Service]
WorkingDirectory=/var/lib/kubelet
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/kubelet
ExecStart=/usr/bin/kubelet \
$KUBE_LOGTOSTDERR \
$KUBE_LOG_LEVEL \
$KUBELET_API_SERVER \
$KUBELET_ADDRESS \
$KUBELET_PORT \
$KUBELET_HOSTNAME \
$KUBE_ALLOW_PRIV \
$KUBELET_POD_INFRA_CONTAINER \
$KUBELET_ARGS
Restart=on-failure
[Install]
WantedBy=multi-user.target配置kubelet的配置檔案： 編輯/etc/kubernetes/kubelet
###
# kubernetes kubelet (minion) config
# The address for the info server to serve on (set to 0.0.0.0 or "" for all interfaces)
KUBELET_ADDRESS="--address=0.0.0.0"
# The port for the info server to serve on
# KUBELET_PORT="--port=10250"
# You may leave this blank to use the actual hostname
KUBELET_HOSTNAME="--hostname-override=10.1.1.2"
# location of the api-server
KUBELET_API_SERVER="--api-servers=http://10.1.1.1:8080"
# pod infrastructure container
#KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=registry.access.redhat.com/rhel7/pod-infrastructure:latest"
# Add your own!
KUBELET_ARGS="--cluster_dns=10.254.159.10 --cluster_domain=cluster.local"kube-proxy
配置service檔案： 編輯/usr/lib/systemd/system/kube-proxy.service
[Unit]
Description=Kubernetes Kube-Proxy Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target
[Service]
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/proxy
ExecStart=/usr/bin/kube-proxy \
$KUBE_LOGTOSTDERR \
$KUBE_LOG_LEVEL \
$KUBE_MASTER \
$KUBE_PROXY_ARGS
Restart=on-failure
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target服務啟動
以上服務啟動均使用systemctl進行啟動，啟動方式
1. systemctl daemon-reload
2. systemctl enable ** 將服務加入開機啟動列表中
3. systemctl start ** 啟動服務
4. systemctl status ** 檢視服務啟動狀態