kubeadm快速部署Kubernetes单节点

 

1. 安装要求

在开始之前,部署Kubernetes集群机器需要满足以下几个条件:

  • 一台或多台机器,操作系统 CentOS7.x-86_x64

  • 硬件配置:2GB或更多RAM,2个CPU或更多CPU,硬盘30GB或更多

  • 集群中所有机器之间网络互通

  • 可以访问外网,需要拉取镜像

  • 禁止swap分区

2. 学习目标

  1. 在所有节点上安装Docker和kubeadm

  2. 部署Kubernetes Master

  3. 部署容器网络插件

  4. 部署 Kubernetes Node,将节点加入Kubernetes集群中

设置主机名
$ hostnamectl set-hostname k8s-master
$ hostnamectl set-hostname k8s-node1

关闭防火墙:
$ systemctl stop firewalld
$ systemctl disable firewalld

关闭selinux:
$ sed -i 's/enforcing/disabled/' /etc/selinux/config 
$ setenforce 0

关闭swap:
$ swapoff -a  $ 临时
$ vim /etc/fstab  $ 永久

添加主机名与IP对应关系(记得设置主机名):
cat <<EOF > /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.31.62 k8s-master
192.168.31.63 k8s-node1
EOF

将桥接的IPv4流量传递到iptables的链:
$ cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF

$ sysctl --system

  

4. 所有节点安装Docker/kubeadm/kubelet

4.1 安装Docker

Kubernetes默认CRI(容器运行时)为Docker,因此先安装Docker。

$ wget https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo -O /etc/yum.repos.d/docker-ce.repo
$ yum -y install docker-ce-18.06.1.ce-3.el7
$ systemctl enable docker && systemctl start docker
$ docker --version
Docker version 18.06.1-ce, build e68fc7a

  

关于docker遇到的坑可以参考此篇文章:https://blog.csdn.net/zhonglinzhang/article/details/85254035 

docker 加速镜像配置

$ mkdir /etc/docker/
cat > /etc/docker/daemon.json <<EOF
{
  "exec-opts": ["native.cgroupdriver=cgroupfs"],
  "registry-mirrors": ["http://f1361db2.m.daocloud.io"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m", "max-file":"3" 
  },
  "storage-driver": "overlay2",
  "storage-opts": [
    "overlay2.override_kernel_check=true"
  ]
}
EOF

# Restart docker.
systemctl daemon-reload
systemctl restart docker

##max-file=3,意味着一个容器有三个日志,分别是id+.json、id+1.json、id+2.json

尝试过修改kubelet的cgroup dirver(文件位置:/lib/systemd/system/kubelet.service.d/10-kubeadm.conf),但是每次启动kubeadm时会被覆盖掉,导致kubelet启动失败,只能修改docker的cgroup dirver设置;
文档中docker驱动是systemd

参考:https://kubernetes.io/docs/setup/production-environment/container-runtimes/

  

  

  

4.2 添加阿里云YUM软件源

$ cat > /etc/yum.repos.d/kubernetes.repo << EOF
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

  

4.3 安装kubeadm,kubelet和kubectl

这里安装最新版

$ yum install -y kubelet  kubeadm  kubectl
$ systemctl enable kubelet

  

5. 部署Kubernetes Master

 

kubeadm init \
  --apiserver-advertise-address=192.168.124.195 \
  --image-repository registry.aliyuncs.com/google_containers \
  --kubernetes-version v1.14.0 \
  --service-cidr=10.1.0.0/16\
  --pod-network-cidr=10.244.0.0/16

这个初始化过程需要几分钟,具体时间取决于你的网络。

由于默认拉取镜像地址k8s.gcr.io国内无法访问,这里指定阿里云镜像仓库地址。

安装完成后根据提示操作

# 所有阶段会打印出来
....
Your Kubernetes master has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

You can now join any number of machines by running the following on each node
as root:

  kubeadm join 192.168.124.194:6443 --token 4b3m3i.hrzetk4qb5uh74e4 --discovery-token-ca-cert-hash sha256:357b0fec02af903e66022019cea82ff3a95264479cb5d222ea8e938df2db3d20

给出一些下面要做的步骤,配置 kubectl, 配置网络组件,以及 worker node 加入的命令。

下面就是跟着提示配置 kubectl

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config  

或者,如果您是 root 用户,则可以运行:

export KUBECONFIG=/etc/kubernetes/admin.conf

 

可以看到 status 为 NotReady, 因为网络组件还没有配置, 下面配置 flannel。

[root@master ~]# kubectl get nodes
NAME     STATUS     ROLES    AGE     VERSION
master   NotReady   master   1h      v1.14.0

  

6. 安装Pod网络插件(CNI)

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

如果下载quay.io镜像不成功可以修改为quay-mirror.qiniu.com 和 registry.aliyuncs.com

例如:

下拉镜像:quay.io/coreos/flannel:v0.10.0-s390x
如果拉取较慢,可以改为:quay-mirror.qiniu.com/coreos/flannel:v0.10.0-s390x

下拉镜像:gcr.io/google_containers/kube-proxy
可以改为: registry.aliyuncs.com/google_containers/kube-proxy

 已修改的kube-flannel.yml(老版本) 新版本的api 有所变化 以新版本为主

---
apiVersion: extensions/v1beta1
kind: PodSecurityPolicy
metadata:
  name: psp.flannel.unprivileged
  annotations:
    seccomp.security.alpha.kubernetes.io/allowedProfileNames: docker/default
    seccomp.security.alpha.kubernetes.io/defaultProfileName: docker/default
    apparmor.security.beta.kubernetes.io/allowedProfileNames: runtime/default
    apparmor.security.beta.kubernetes.io/defaultProfileName: runtime/default
spec:
  privileged: false
  volumes:
    - configMap
    - secret
    - emptyDir
    - hostPath
  allowedHostPaths:
    - pathPrefix: "/etc/cni/net.d"
    - pathPrefix: "/etc/kube-flannel"
    - pathPrefix: "/run/flannel"
  readOnlyRootFilesystem: false
  # Users and groups
  runAsUser:
    rule: RunAsAny
  supplementalGroups:
    rule: RunAsAny
  fsGroup:
    rule: RunAsAny
  # Privilege Escalation
  allowPrivilegeEscalation: false
  defaultAllowPrivilegeEscalation: false
  # Capabilities
  allowedCapabilities: ['NET_ADMIN']
  defaultAddCapabilities: []
  requiredDropCapabilities: []
  # Host namespaces
  hostPID: false
  hostIPC: false
  hostNetwork: true
  hostPorts:
  - min: 0
    max: 65535
  # SELinux
  seLinux:
    # SELinux is unsed in CaaSP
    rule: 'RunAsAny'
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: flannel
rules:
  - apiGroups: ['extensions']
    resources: ['podsecuritypolicies']
    verbs: ['use']
    resourceNames: ['psp.flannel.unprivileged']
  - apiGroups:
      - ""
    resources:
      - pods
    verbs:
      - get
  - apiGroups:
      - ""
    resources:
      - nodes
    verbs:
      - list
      - watch
  - apiGroups:
      - ""
    resources:
      - nodes/status
    verbs:
      - patch
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: flannel
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: flannel
subjects:
- kind: ServiceAccount
  name: flannel
  namespace: kube-system
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: flannel
  namespace: kube-system
---
kind: ConfigMap
apiVersion: v1
metadata:
  name: kube-flannel-cfg
  namespace: kube-system
  labels:
    tier: node
    app: flannel
data:
  cni-conf.json: |
    {
      "name": "cbr0",
      "plugins": [
        {
          "type": "flannel",
          "delegate": {
            "hairpinMode": true,
            "isDefaultGateway": true
          }
        },
        {
          "type": "portmap",
          "capabilities": {
            "portMappings": true
          }
        }
      ]
    }
  net-conf.json: |
    {
      "Network": "10.244.0.0/16",
      "Backend": {
        "Type": "vxlan"
      }
    }
---
apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: kube-flannel-ds-amd64
  namespace: kube-system
  labels:
    tier: node
    app: flannel
spec:
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      hostNetwork: true
      nodeSelector:
        beta.kubernetes.io/arch: amd64
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay-mirror.qiniu.com/coreos/flannel:v0.11.0-amd64
        command:
        - cp
        args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conflist
        volumeMounts:
        - name: cni
          mountPath: /etc/cni/net.d
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      containers:
      - name: kube-flannel
        image: quay-mirror.qiniu.com/coreos/flannel:v0.11.0-amd64
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
          limits:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
             add: ["NET_ADMIN"]
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        volumeMounts:
        - name: run
          mountPath: /run/flannel
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      volumes:
        - name: run
          hostPath:
            path: /run/flannel
        - name: cni
          hostPath:
            path: /etc/cni/net.d
        - name: flannel-cfg
          configMap:
            name: kube-flannel-cfg
---
apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: kube-flannel-ds-arm64
  namespace: kube-system
  labels:
    tier: node
    app: flannel
spec:
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      hostNetwork: true
      nodeSelector:
        beta.kubernetes.io/arch: arm64
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay-mirror.qiniu.com/coreos/flannel:v0.11.0-arm64
        command:
        - cp
        args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conflist
        volumeMounts:
        - name: cni
          mountPath: /etc/cni/net.d
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      containers:
      - name: kube-flannel
        image: quay-mirror.qiniu.com/coreos/flannel:v0.11.0-arm64
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
          limits:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
             add: ["NET_ADMIN"]
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        volumeMounts:
        - name: run
          mountPath: /run/flannel
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      volumes:
        - name: run
          hostPath:
            path: /run/flannel
        - name: cni
          hostPath:
            path: /etc/cni/net.d
        - name: flannel-cfg
          configMap:
            name: kube-flannel-cfg
---
apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: kube-flannel-ds-arm
  namespace: kube-system
  labels:
    tier: node
    app: flannel
spec:
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      hostNetwork: true
      nodeSelector:
        beta.kubernetes.io/arch: arm
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay-mirror.qiniu.com/coreos/flannel:v0.11.0-arm
        command:
        - cp
        args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conflist
        volumeMounts:
        - name: cni
          mountPath: /etc/cni/net.d
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      containers:
      - name: kube-flannel
        image: quay-mirror.qiniu.com/coreos/flannel:v0.11.0-arm
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
          limits:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
             add: ["NET_ADMIN"]
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        volumeMounts:
        - name: run
          mountPath: /run/flannel
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      volumes:
        - name: run
          hostPath:
            path: /run/flannel
        - name: cni
          hostPath:
            path: /etc/cni/net.d
        - name: flannel-cfg
          configMap:
            name: kube-flannel-cfg
---
apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: kube-flannel-ds-ppc64le
  namespace: kube-system
  labels:
    tier: node
    app: flannel
spec:
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      hostNetwork: true
      nodeSelector:
        beta.kubernetes.io/arch: ppc64le
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay-mirror.qiniu.com/coreos/flannel:v0.11.0-ppc64le
        command:
        - cp
        args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conflist
        volumeMounts:
        - name: cni
          mountPath: /etc/cni/net.d
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      containers:
      - name: kube-flannel
        image: quay-mirror.qiniu.com/coreos/flannel:v0.11.0-ppc64le
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
          limits:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
             add: ["NET_ADMIN"]
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        volumeMounts:
        - name: run
          mountPath: /run/flannel
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      volumes:
        - name: run
          hostPath:
            path: /run/flannel
        - name: cni
          hostPath:
            path: /etc/cni/net.d
        - name: flannel-cfg
          configMap:
            name: kube-flannel-cfg
---
apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: kube-flannel-ds-s390x
  namespace: kube-system
  labels:
    tier: node
    app: flannel
spec:
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      hostNetwork: true
      nodeSelector:
        beta.kubernetes.io/arch: s390x
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay-mirror.qiniu.com/coreos/flannel:v0.11.0-s390x
        command:
        - cp
        args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conflist
        volumeMounts:
        - name: cni
          mountPath: /etc/cni/net.d
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      containers:
      - name: kube-flannel
        image: quay-mirror.qiniu.com/coreos/flannel:v0.11.0-s390x
        command:
        - /opt/bin/flanneld
        args:
        - --ip-masq
        - --kube-subnet-mgr
        resources:
          requests:
            cpu: "100m"
            memory: "50Mi"
          limits:
            cpu: "100m"
            memory: "50Mi"
        securityContext:
          privileged: false
          capabilities:
             add: ["NET_ADMIN"]
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        volumeMounts:
        - name: run
          mountPath: /run/flannel
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      volumes:
        - name: run
          hostPath:
            path: /run/flannel
        - name: cni
          hostPath:
            path: /etc/cni/net.d
        - name: flannel-cfg
          configMap:
            name: kube-flannel-cfg

  

再来看状态 

$ kubectl get pods --all-namespaces
NAMESPACE     NAME                              READY     STATUS    RESTARTS   AGE
kube-system   coredns-78fcdf6894-4744c          1/1       Running   0          5m
kube-system   coredns-78fcdf6894-jbvhd          1/1       Running   0          5m
kube-system   kube-apiserver-master1            1/1       Running   0          5m
kube-system   kube-controller-manager-master1   1/1       Running   0          5m
kube-system   kube-flannel-ds-amd64-kp7cr       1/1       Running   0          11s
kube-system   kube-proxy-6778v                  1/1       Running   0          5m
kube-system   kube-scheduler-master1            1/1       Running   0          5m

$ kubectl get nodes
NAME      STATUS    ROLES     AGE       VERSION
master1   Ready     master    1h        v1.14.0


$ kubectl get cs
NAME                 STATUS    MESSAGE              ERROR
scheduler            Healthy   ok
controller-manager   Healthy   ok
etcd-0               Healthy   {"health": "true"}

 

如果看到错误信息
kubectl get cs

controller-manager   Unhealthy   Get http://127.0.0.1:10252/healthz: dial tcp 127.0.0.1:10252: connect: connection refused
scheduler            Unhealthy   Get http://127.0.0.1:10251/healthz: dial tcp 127.0.0.1:10251: connect: connection refused

1、先查看本地的端口,可以确认没有启动10251、10252端口
2、确认kube-scheduler和kube-controller-manager组件配置是否禁用了非安全端口

配置文件路径:/etc/kubernetes/manifests/scheduler.conf 、/etc/kubernetes/manifests/controller-manager.conf

如controller-manager组件的配置如下:可以去掉--port=0这个设置,然后重启sudo systemctl restart kubelet

 

在k8s最新版本 v1.16.3 你看到的是这样的
$ kubectl get cs
NAME                         AGE
controller-manager          <unknown>
scheduler                   <unknown>
etcd-0                      <unknown>

开启master节点允许部署pod: kubectl taint nodes --all node-role.kubernetes.io/master-

不执行这条命令 创建会报错误:nodes are available: 1 node(s) had taints that the pod didn't tolerate.

master 节点的配置基本完成了。

Node 配置

就是执行之前 init 最后打出的那个命令

sudo kubeadm join 192.168.124.195:6443 --token qn1tr1.3xpu3qhu7ettn4gv \
    --discovery-token-ca-cert-hash sha256:932f99ce7b294b63dd0f511da047c6ea9cf56fa9d8b4b1df9be70013b0c049c9  

如果不幸,你忘记了上面的命令并且找不到了,可以通过 kubeadm token create --print-join-command 来获取

 

master复制admin文件到node节点

scp /etc/kubernetes/admin.conf root@node1:/etc/kubernetes/admin.conf

  

node操作完之后,再来 master 节点看看

$ kubectl get nodes
NAME      STATUS    ROLES     AGE       VERSION
master1   Ready     master    7m        v1.14.0
node1     Ready     <none>    18s       v1.14.0

用一个简单pod测试下

kubectl run -i --tty busybox --image=busybox --restart=Never -- sh

# 正常执行,再看看调度情况
$ kubectl get pod --show-all -o wide
NAME      READY     STATUS      RESTARTS   AGE       IP           NODE
busybox   0/1       Completed   0          48s       10.244.1.2   node1

其他

master节点的token 24小时过期后,可以通过命令产生新的token:

kubeadm token list

创建永不过期的token
kubeadm token create --ttl 0

master节点上运行命令,可查询discovery-token-ca-cert-hash值:
openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'

重新加入节点
kubeadm join 192.168.124.195:6443 --token 8xwg8u.lkj382k9ox58qkw9 \
--discovery-token-ca-cert-hash sha256:86291bed442dd1dcd6c26f2213208e10cab0f87763f44e0edf01fa670cd9e8b

  

查看 kubeadm 的配置

kubeadm config view

 

卸载集群

kubeadm reset

  

 

posted @ 2019-04-08 16:21  执酒  阅读(3583)  评论(0编辑  收藏