k8s 集群搭建 ubuntu环境

Kubernetes工作流程：

1、准备好一个包含应用程序的Deployment的yml文件，然后通过kubectl客户端工具发送给ApiServer。

2、ApiServer接收到客户端的请求并将资源内容存储到数据库(etcd)中。

3、Controller组件(包括scheduler、replication、endpoint)监控资源变化并作出反应。

4、ReplicaSet检查数据库变化，创建期望数量的pod实例。

5、Scheduler再次检查数据库变化，发现尚未被分配到具体执行节点(node)的Pod，然后根据一组相关规则将pod分配到可以运行它们的节点上，并更新数据库，记录pod分配情况。

6、Kubelete监控数据库变化，管理后续pod的生命周期，发现被分配到它所在的节点上运行的那些pod。如果找到新pod，则会在该节点上运行这个新pod。

7、kuberproxy运行在集群各个主机上，管理网络通信，如服务发现、负载均衡。例如当有数据发送到主机时，将其路由到正确的pod或容器。对于从主机上发出的数据，它可以基于请求地址发现远程服务器，并将数据正确路由，在某些情况下会使用轮训调度算法(Round-robin)将请求发送到集群中的多个实例。

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top

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ip             name    info  system

192.168.11.144 master  2c2G    ubuntu

192.168.11.145 node      2c2G    ubuntu

all nodes

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all nodes快速安装 一步步

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swapoff -a  #开机时需要 关闭swap内存

ufw disable

cp /etc/apt/sources.list /etc/apt/sources.list.default

echo "" >> /etc/apt/sources.list

echo "deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse                "  >> /etc/apt/sources.list

echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse      "  >> /etc/apt/sources.list

echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse        "  >> /etc/apt/sources.list

echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse      "  >> /etc/apt/sources.list

echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse      "  >> /etc/apt/sources.list

echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse            "  >> /etc/apt/sources.list

echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse  "  >> /etc/apt/sources.list

echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse    "  >> /etc/apt/sources.list

echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse  "  >> /etc/apt/sources.list

echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse  "  >> /etc/apt/sources.list

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apt-get update && apt-get install -y apt-transport-https

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curl https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | apt-key add -

echo "deb https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial main" >/etc/apt/sources.list.d/kubernetes.list

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wget -qO- https://get.docker.com/ | sh

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sudo apt-get install -y kubelet kubeadm kubectl kubernetes-cni

systemctl enable kubelet

all nodes详细步骤

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##disable swap

swapoff -a

##iptables

ufw disable

#分别更改hostname

hostnamectl set-hostname master

#添加域名解析

cat <>/etc/hosts

192.168.11.144 master

192.168.11.145 node

EOF

#配置国内apt源， 以下为阿里源，将 /etc/apt/sources.list 中内容替换如下

cp /etc/apt/sources.list /etc/apt/sources.list.default

echo "" >> /etc/apt/sources.list

echo "deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse                "  >> /etc/apt/sources.list

echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse      "  >> /etc/apt/sources.list

echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse        "  >> /etc/apt/sources.list

echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse      "  >> /etc/apt/sources.list

echo "deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse      "  >> /etc/apt/sources.list

echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse            "  >> /etc/apt/sources.list

echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse  "  >> /etc/apt/sources.list

echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse    "  >> /etc/apt/sources.list

echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse  "  >> /etc/apt/sources.list

echo "deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse  "  >> /etc/apt/sources.list

#配置国内Kubernetes源

apt-get update && apt-get install -y apt-transport-https

curl https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | apt-key add -

echo "deb https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial main" >/etc/apt/sources.list.d/kubernetes.list

#配置国内docker 源  ##不推荐，用下面 wget -qO- https://get.docker.com/ | sh 的直接安装

sudo apt install apt-transport-https ca-certificates software-properties-common curl

curl -fsSL https://mirrors.ustc.edu.cn/docker-ce/linux/ubuntu/gpg | sudo apt-key add -

sudo add-apt-repository "deb [arch=amd64] https://mirrors.ustc.edu.cn/docker-ce/linux/ubuntu \

$(lsb_release -cs) stable"

sudo apt update

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#安装docker

wget -qO- https://get.docker.com/ | sh

#安装k8s工具

sudo apt-get install -y kubelet kubeadm kubectl kubernetes-cni

systemctl enable kubelet

master

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##初始化  ##如果初始化失败，可以用kubeadm reset 来清理环境

或者加上：  --ignore-preflight-errors=all

--pod-network-cidr=10.244.0.0/16  由后面的 CNI 插件 flannel 的配置一致

kubeadm init --kubernetes-version=1.15.0 --apiserver-advertise-address=192.168.11.144 --image-repository registry.aliyuncs.com/google_containers --service-cidr=10.245.0.0/16 --pod-network-cidr=10.244.0.0/16  --ignore-preflight-errors=all

##执行成功会出现如下节点加入cmd：

kubeadm join 192.168.11.144:6443 --token 65m73j.ok6rs1tbsyu5lm7h \

    --discovery-token-ca-cert-hash sha256:d42ae01be24f317ab32245c4923ef4f99025c0f6c0b93ca25807300059abdb02

##token过期,重新生成

kubeadm token create --print-join-command

all node

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##添加token  admin.conf文件来自master，用于获取master 的 kubectl 权限

mkdir -p /root/.kube

cp -i /etc/kubernetes/admin.conf  /root/.kube/config

#scp  /etc/kubernetes/admin.conf root@node:/root/.kube/config

chown $(id -u):$(id -g) /root/.kube/config

node

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##节点 加入集群

ssh node 主机：

kubeadm join 192.168.11.144:6443 --token ev0juo.z4c46l9h1i0i8tf8 \

    --discovery-token-ca-cert-hash sha256:f0e1c706859bacb3b6d8cc40f27b6fdf5af2fce8b889137ee0163c3454ac1378 --ignore-preflight-errors=all

##查看节点

kubectl get nodes

kubectl describe node node

##加入超时

swapoff -a

kubeadm reset

systemctl daemon-reload

systemctl restart kubelet

ufw disable

再次执行加入节点的命令

node status

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kubectl get nodes 

## notready 逐一查看：这里是镜像拉取失败

kubectl get pod --all-namespaces

kubectl describe pod XXX --namespace=XXX

##更新需要的镜像：

ssh master

cat $HOME/imagepath.txt

quay.io/coreos/flannel:v0.11.0-amd64

wget -O- https://raw.githubusercontent.com/zhwill/LinuxShell/master/pull-aliyun-images.sh | sh

kubectl get nodes  -n monitoring -o wide

node roles

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为节点名为 node 的添加master角色

kubectl label nodes node node-role.kubernetes.io/master= 

为节点名为 node 的添加node角色

kubectl label nodes node node-role.kubernetes.io/node=

为节点名为 node 的去除master角色

kubectl label nodes node node-role.kubernetes.io/master-

##允许 master 作pod部署  1 node(s) had taints that the pod didn't tolerate

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

CNI 网络  flannel

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kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

#这个文件默认使用 10.244.0.0/16  的网段，所以前面 kubeadm init 梗概为默认的 网段

#kubectl get svc,pod -n kube-system

#当某个节点被重启或者还原快照后，需要重启虚拟机以保证网络连接

运行第一个 pod

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apiVersion: v1

kind: Pod

metadata:

  name: nginx

spec:                                 

  containers:

  - name: nginx

    image: nginx:1.7.9

    ports:

    - containerPort: 80

                         

kubectl create namespace test-hope

kubectl create -f nginx-pod.yaml  -n test-hope

kubectl describe  pod nginx -n test-hope

###查看详细信息时 err:  /run/flannel/subnet.env

scp master: /run/flannel/subnet.env ---> node

## error : failed: rpc error: code = Unknown desc = NetworkPlugin cni failed to set up pod "nginx-8586cf59-rm4sh_default" network: failed to set bridge addr: "cni0" already has an IP address different from 10.244.2.1/24

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节点主机 node:

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kubeadm reset

systemctl stop kubelet

systemctl stop docker

rm -rf /var/lib/cni/

rm -rf /var/lib/kubelet/*

rm -rf /etc/cni/

ifconfig cni0 down

ifconfig flannel.1 down

ifconfig docker0 down

ip link delete cni0

ip link delete flannel.1

systemctl start docker

master: 获取master的join token

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kubeadm token create --print-join-command

master: 集群日志查看

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journalctl -xefu kubelet

CoreDns 域名测试

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vim dig.yaml

apiVersion: v1

kind: Pod

metadata:

  name: dig

  namespace: test-hope

spec:

  containers:

  - name: dig

    image:  docker.io/azukiapp/dig

    command:

      - sleep

      - "3600"

    imagePullPolicy: IfNotPresent

  restartPolicy: Always

                         

dig-test:

kubectl exec -ti dig -n ingress-nginx  -- nslookup myservice.ingress-nginx

kubectl exec -ti dig -n ingress-nginx  -- nslookup www.baidu.cn