kubeadm搭建环境k8s(v1.9)集群环境

# kubeadm搭建环境

 

**备注：以下安装除docker外，其他均不需要访问外网**

docker version 18.07，安装方法见博文“CentOS7.2g安装docker-ce”

https://blog.csdn.net/z770816239/article/details/80560747

## 安装docker


配置docker
 

vi /etc/docker/daemon.json


{
  "registry-mirrors": ["https://mdvdy488.mirror.aliyuncs.com"]
}
```


mkdir -p /etc/systemd/system/docker.service.d
cat >> /etc/systemd/system/docker.service.d/http-proxy.conf <

保存并重启docker


## 关闭防火墙
```shell

swapoff -a
setenforce 0
sed -i "s|SELINUX=.*|SELINUX=disabled|g" /etc/selinux/config
systemctl stop firewalld

```

## 查看net.bridge.bridge-nf-call-iptables是否为1

`sysctl net.bridge.bridge-nf-call-iptables`


`sysctl net.bridge.bridge-nf-call-ip6tables`


```shell
cat <  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system
```

## 拷贝安装所需文件到机器上


rpms、yaml


## 安装kubelet kubectl kubeadm

```shell
cd rpms
rpm -ivh *
```

#### 修改kubelet的配置


- 替换`/etc/systemd/system/kubelet.service.d/10-kubeadm.conf`中的`Environment="KUBELET_CGROUP_ARGS=--cgroup-driver=cgroupfs"
`和`docker info`的cgroups driver一致


- 增加kubelet启动每个pod的network/ipc namespaces的自定义容器镜像


`vi /etc/systemd/system/kubelet.service.d/10-kubeadm.conf`


`Environment="KUBELET_EXTRA_ARGS=--pod-infra-container-image=gcr.io/google_containers/pause-amd64:3.0"`


#### 重启kubelet服务

`systemctl enable kubelet && systemctl restart kubelet`

## 初始化集群

`kubeadm init --config yaml/kubeadm.yaml`


```shell
[init] Using Kubernetes version: v1.9.2
[init] Using Authorization modes: [Node RBAC]
[preflight] Running pre-flight checks.
        [WARNING SystemVerification]: docker version is greater than the most recently validated version. Docker version: 17.12.0-ce. Max validated version: 17.03
        [WARNING FileExisting-crictl]: crictl not found in system path
[preflight] Starting the kubelet service
[certificates] Generated ca certificate and key.
[certificates] Generated apiserver certificate and key.
[certificates] apiserver serving cert is signed for DNS names [localhost.hcm.domain.com kubernetes kubernetes.                            default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 ]
[certificates] Generated apiserver-kubelet-client certificate and key.
[certificates] Generated sa key and public key.
[certificates] Generated front-proxy-ca certificate and key.
[certificates] Generated front-proxy-client certificate and key.
[certificates] Valid certificates and keys now exist in "/etc/kubernetes/pki"
[kubeconfig] Wrote KubeConfig file to disk: "admin.conf"
[kubeconfig] Wrote KubeConfig file to disk: "kubelet.conf"
[kubeconfig] Wrote KubeConfig file to disk: "controller-manager.conf"
[kubeconfig] Wrote KubeConfig file to disk: "scheduler.conf"
[controlplane] Wrote Static Pod manifest for component kube-apiserver to "/etc/kubernetes/manifests/kube-apiserver.yaml"
[controlplane] Wrote Static Pod manifest for component kube-controller-manager to "/etc/kubernetes/manifests/kube-controller-manager.yaml"
[controlplane] Wrote Static Pod manifest for component kube-scheduler to "/etc/kubernetes/manifests/kube-scheduler.yaml"
[etcd] Wrote Static Pod manifest for a local etcd instance to "/etc/kubernetes/manifests/etcd.yaml"
[init] Waiting for the kubelet to boot up the control plane as Static Pods from directory "/etc/kubernetes/manifests".
[init] This might take a minute or longer if the control plane images have to be pulled.
[apiclient] All control plane components are healthy after 157.104694 seconds
[uploadconfig] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[markmaster] Will mark node localhost.hcm.domain.com as master by adding a label and a taint
[markmaster] Master localhost.hcm.domain.com tainted and labelled with key/value: node-role.kubernetes.io/master=""
[bootstraptoken] Using token: 
[bootstraptoken] Configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials
[bootstraptoken] Configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token
[bootstraptoken] Configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
[bootstraptoken] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
[addons] Applied essential addon: kube-dns
[addons] Applied essential addon: kube-proxy


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


```

根据提示执行如下命令:

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

## 安装flannel


在未安装podnetwork的时候，kube-dns的状态为pending


```shell

[root@localhost ~]# kubectl get pods --namespace=kube-system
NAME                                               READY     STATUS              RESTARTS   AGE
etcd-localhost.hcm.domain.com                      1/1       Running             0          38s
kube-apiserver-localhost.hcm.domain.com            1/1       Running             1          1m
kube-controller-manager-localhost.hcm.domain.com   1/1       Running             0          40s
kube-dns-6f4fd4bdf-dndm6                           0/3       Pending             0          26s
kube-scheduler-localhost.hcm.domain.com            1/1       Running             0          1m

```

### 执行安装

`kubectl apply -f yaml/kube-flannel.yml`

### 安装后检查


```shell

[root@localhost ~]# kubectl get pods --namespace=kube-system
NAME                                               READY     STATUS    RESTARTS   AGE
etcd-localhost.hcm.domain.com                      1/1       Running   0          5m
kube-apiserver-localhost.hcm.domain.com            1/1       Running   1          5m
kube-controller-manager-localhost.hcm.domain.com   1/1       Running   0          5m
kube-dns-6f4fd4bdf-dndm6                           3/3       Running   0          4m
kube-flannel-ds-gj992                              1/1       Running   0          4m
kube-proxy-pct9t                                   1/1       Running   0          4m
kube-scheduler-localhost.hcm.domain.com            1/1       Running   0          6m

```


## 初始化master


默认master是不允许进行pod的调度的，如果想要使用master，需要执行下面的命令。

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

## 安装dashboard
 

`kubectl create -f kubernetes-dashboard.yaml`

访问dashboard

`kubectl proxy --address 0.0.0.0 --accept-hosts '.*'`


http://192.168.122.115:8001/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/#!/ingress?namespace=default


http://192.168.122.115:8001/ui

## 添加node节点


#### 修改hostname和/etc/hosts


每个节点的上述两项需保证不一致，否则添加节点会导致节点错乱，引起异常


#### 安装docker


#### 关闭防火墙


#### 查看net.bridge.bridge-nf-call-iptables是否为1


### 安装kubelet kubectl kubeadm


拷贝rpms到机器上

```shell
rpm -ivh *
systemctl enable kubelet && systemctl start kubelet
```

#### 添加节点到集群


在需要添加的节点上执行下面的命令。

`kubeadm join --token  : --discovery-token-ca-cert-hash sha256:`

#### token获取

`kubeadm token list`

#### hash获取

`openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'`

成功后信息：

```shell
[preflight] Running pre-flight checks.
        [WARNING SystemVerification]: docker version is greater than the most recently validated version. Docker version: 17.09.1-ce. Max validated version: 17.03
        [WARNING FileExisting-crictl]: crictl not found in system path
[discovery] Trying to connect to API Server ":"
[discovery] Created cluster-info discovery client, requesting info from "https://:"
[discovery] Requesting info from "https://:" again to validate TLS against the pinned public key
[discovery] Cluster info signature and contents are valid and TLS certificate validates against pinned roots, will use API Server ":"
[discovery] Successfully established connection with API Server ":"


This node has joined the cluster:
* Certificate signing request was sent to master and a response
  was received.
* The Kubelet was informed of the new secure connection details.


Run 'kubectl get nodes' on the master to see this node join the cluster.
```

## 关闭集群
 

kubectl drain  --delete-local-data --force --ignore-daemonsets
kubectl delete node 
kubeadm reset

 

############

kubeadm.yaml

#############

apiVersion: kubeadm.k8s.io/v1alpha1
kind: MasterConfiguration
etcd:
  extraArgs:
    'listen-client-urls': 'http://127.0.0.1:2379'
    'advertise-client-urls': 'http://127.0.0.1:2379'
    'listen-peer-urls': 'http://127.0.0.1:2380'
    'data-dir': '/var/lib/etcd'
  image: gcr.io/google_containers/etcd-amd64:3.1.11
kubernetesVersion: 1.9.2
tokenTTL: 0s
networking:

  podSubnet: 10.244.0.0/16

 

 

################

kube-flannel.yaml

################

---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: flannel
rules:
  - 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",
      "type": "flannel",
      "delegate": {
        "isDefaultGateway": true
      }
    }
  net-conf.json: |
    {
      "Network": "10.244.0.0/16",
      "Backend": {
        "Type": "vxlan"
      }
    }
---
apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: kube-flannel-ds
  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:
      - key: node-role.kubernetes.io/master
        operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay.io/coreos/flannel:v0.9.1-amd64
        command:
        - cp
        args:
        - -f
        - /etc/kube-flannel/cni-conf.json
        - /etc/cni/net.d/10-flannel.conf
        volumeMounts:
        - name: cni
          mountPath: /etc/cni/net.d
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      containers:
      - name: kube-flannel
        image: quay.io/coreos/flannel:v0.9.1-amd64
        command: [ "/opt/bin/flanneld", "--ip-masq", "--kube-subnet-mgr" ]
        securityContext:
          privileged: true
        env:
        - name: POD_NAME
          valueFrom:
            fieldRef:
              fieldPath: metadata.name
        - name: POD_NAMESPACE
          valueFrom:
            fieldRef:
              fieldPath: metadata.namespace
        volumeMounts:
        - name: run
          mountPath: /run
        - name: flannel-cfg
          mountPath: /etc/kube-flannel/
      volumes:
        - name: run
          hostPath:
            path: /run
        - name: cni
          hostPath:
            path: /etc/cni/net.d
        - name: flannel-cfg
          configMap:
            name: kube-flannel-cfg