kubeadm配置k8s

时间有限，只是列出了安装k8s的配置步骤，没有写明为什么这样做，以后有空再补上。如果有什么不明白的，欢迎在评论下留下你的问题，有空会回复。

服务器规划

服务器名称	角色	IP地址	系统
master	master	192.168.83.133	CentOS 7.3
kworker1	worker	192.168.83.134	CentOS 7.3
kworker2	worker	192.168.83.135	CentOS 7.3

配置hostname

如配置master的hostname
1. 在/etc/hosts添加127.0.0.1 master记录
2. echo “master” > /etc/hostname
3. hostname master

配置iptables

所有机器执行

chmod +x /etc/rc.d/rc.local
iptables -I INPUT -s 192.168.83.0/24 -j ACCEPT
iptables -I FORWARD -j ACCEPT
echo 'iptables -I INPUT -s 192.168.83.0/24 -j ACCEPT' >> /etc/rc.d/rc.local
echo 'iptables -I FORWARD -j ACCEPT' >> /etc/rc.d/rc.local

其中192.168.83.0/24为k8s节点的所在IP段。

安装docker,kubelet等

所有机器运行。
更新系统

yum -y update

设置aliyun的源

cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=0
EOF

关闭selinux

sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
setenforce 0

安装kubelet和docker

yum install -y docker kubelet kubeadm kubectl kubernetes-cni
systemctl enable docker
systemctl start docker
systemctl enable kubelet

配置kubelet的源为aliyun(此aliyun源为本人从google的源搬过来的)

cat > /etc/systemd/system/kubelet.service.d/20-pod-infra-image.conf <<EOF
[Service]
Environment="KUBELET_EXTRA_ARGS=--pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/centos-bz/pause-amd64:3.0"
EOF
systemctl daemon-reload
systemctl restart kubelet
reboot

配置内核

所有机器运行。

cat <<EOF > /etc/sysctl.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl -p

镜像版本

由于国内无法访问google源，所以本人把主要的k8s镜像搬到了aliyun。而etcd和dns,pause的版本可以在源码的以下路径找到。可以根据相应的版本创建源。
– etcd版本：cmd/kubeadm/app/images/images.go
– dns版本：cmd/kubeadm/app/phases/addons/manifests.go
– pause-amd64: cmd/kubeadm/app/master/templates.go:

初始化master

在master运行

初始化

初始化k8s并锁定v1.6.2版本。

export KUBE_REPO_PREFIX=registry.cn-hangzhou.aliyuncs.com/centos-bz
kubeadm init --pod-network-cidr 10.244.0.0/16 --kubernetes-version=v1.6.2

拉取镜像需要一定的时间，可以在master执行docker images查看已下载的镜像。

配置KUBECONFIG环境变量

cp -f /etc/kubernetes/admin.conf $HOME/
chown $(id -u):$(id -g) $HOME/admin.conf
export KUBECONFIG=$HOME/admin.conf
echo "export KUBECONFIG=$HOME/admin.conf" >>  ~/.bash_profile

允许master运行pod

如果需要master作为worker运行pod，执行

kubectl taint nodes --all node-role.kubernetes.io/master-

添加node

在worker1和worker2执行。

kubeadm join --token a30d18.1600388a52b3b472 192.168.83.133:6443

以上命令为在master初始化成功后在控制台输出的命令。
查看pod运行情况:

kubectl get pods -n kube-system

安装flannel

kubectl create -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel-rbac.yml
curl -sSL "https://github.com/coreos/flannel/blob/master/Documentation/kube-flannel.yml?raw=true" | kubectl create -f -

安装dashboard

curl -sSL https://raw.githubusercontent.com/kubernetes/dashboard/master/src/deploy/kubernetes-dashboard.yaml | sed 's#gcr.io/google_containers#registry.cn-hangzhou.aliyuncs.com/centos-bz#' | kubectl create -f -

执行如下命令来找到dashboard的端口:

[root@master ~]# kubectl get service  -n kube-system | grep kubernetes-dashboard
kubernetes-dashboard   10.100.79.47   <nodes>       80:32574/TCP    4h

如上端口为32574，可以在浏览器打开http://worker1:32574访问控制面板。

安装nginx ingress controller

安装default backend

curl -sSL https://raw.githubusercontent.com/kubernetes/ingress/nginx-0.9.0-beta.5/examples/deployment/nginx/default-backend.yaml | sed 's#gcr.io/google_containers#registry.cn-hangzhou.aliyuncs.com/centos-bz#' |  kubectl apply -f -

安装nginx ingress controller

新建ingress-rbac.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: ingress
  namespace: kube-system

---

kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: ingress
subjects:
  - kind: ServiceAccount
    name: ingress
    namespace: kube-system
roleRef:
  kind: ClusterRole
  name: cluster-admin
  apiGroup: rbac.authorization.k8s.io

新建nginx-ingress.yml:

apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: nginx-ingress-lb
  labels:
    name: nginx-ingress-lb
  namespace: kube-system
spec:
  template:
    metadata:
      labels:
        name: nginx-ingress-lb
      annotations:
        prometheus.io/port: '10254'
        prometheus.io/scrape: 'true'
    spec:
      terminationGracePeriodSeconds: 60
      serviceAccountName: ingress
      hostNetwork: true
      containers:
      - image: registry.cn-hangzhou.aliyuncs.com/centos-bz/nginx-ingress-controller:0.9.0-beta.5
        name: nginx-ingress-lb
        readinessProbe:
          httpGet:
            path: /healthz
            port: 10254
            scheme: HTTP
        livenessProbe:
          httpGet:
            path: /healthz
            port: 10254
            scheme: HTTP
          initialDelaySeconds: 10
          timeoutSeconds: 1
        ports:
        - containerPort: 80
          hostPort: 80
        - containerPort: 443
          hostPort: 443
        env:
          - name: POD_NAME
            valueFrom:
              fieldRef:
                fieldPath: metadata.name
          - name: POD_NAMESPACE
            valueFrom:
              fieldRef:
                fieldPath: metadata.namespace
        args:
        - /nginx-ingress-controller
        - --default-backend-service=$(POD_NAMESPACE)/default-http-backend

创建nginx ingress controller

kubectl create -f ingress-rbac.yaml
kubectl apply -f nginx-ingress.yml

在worker1和worker2使用ss -nlpt命令查看80和443端口是否已经监听。

测试

测试ingress

部署echo server

kubectl run echoheaders --image=registry.cn-hangzhou.aliyuncs.com/centos-bz/echoserver:1.4 --replicas=1 --port=8080

新建service

kubectl expose deployment echoheaders --port=80 --target-port=8080 --name=echoheaders-x
kubectl expose deployment echoheaders --port=80 --target-port=8080 --name=echoheaders-y

新建ingress.yaml:

# An Ingress with 2 hosts and 3 endpoints
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: echomap
spec:
  rules:
  - host: foo.bar.com
    http:
      paths:
      - path: /foo
        backend:
          serviceName: echoheaders-x
          servicePort: 80
  - host: bar.baz.com
    http:
      paths:
      - path: /bar
        backend:
          serviceName: echoheaders-y
          servicePort: 80
      - path: /foo
        backend:
          serviceName: echoheaders-x
          servicePort: 80

新建规则

kubectl create -f ingress.yaml

使用curl测试：

curl 192.168.83.135/foo -H 'Host: foo.bar.com'
curl 192.168.83.135/other -H 'Host: foo.bar.com'

pod-service

todo

external-to-service

todo

pod-to-pod

todo

dns测试

todo