K8s集群搭建(kubeadm方案)

K8s集群搭建(kubeadm方案)

1、最少3臺Centos
A、至少2核CPU+2G內存+20G硬盤
B、必須在同一網段
本示例中分配為：

Master：10.170.0.7
Worker1：10.170.0.8
Worker2：10.170.0.9

2、ip addr確認是否有分配到IPV4地址。沒有的話nmtui，Automatically connect打上勾

3、用SSH連接

4、禁用防火墻，

systemctl stop firewalld & systemctl disable firewalld

5、禁用SELINUX

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

6、禁用swap

    A、swapoff -a
    B、vi /etc/fstab，注釋掉swap

7、重啟服務器，使其生效。

reboot

8、添加k8s源，建議使用阿里或者163的

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=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

9、安裝kubelet、kubeadm、kubectl

yum install -y kubectl kubeadm kubectl

10、kube-proxy開啟ipvs

vi /etc/sysctl.d/k8s.conf
vm.swappiness = 0
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1

modprobe br_netfilter
sysctl -p /etc/sysctl.d/k8s.conf

cat > /etc/sysconfig/modules/ipvs.modules <<EOF
#!/bin/bash
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack_ipv4
EOF

chmod 755 /etc/sysconfig/modules/ipvs.modules && bash /etc/sysconfig/modules/ipvs.modules && lsmod | grep -e ip_vs -e nf_conntrack_ipv4

接下來還需要確保各個節點上已經安裝了ipset軟件包

yum install -y ipset

。 為了便于查看ipvs的代理規則，最好安裝一下管理工具

yum install -y ipvsadm

。

11、安裝docker

yum install -y docker
systemctl start docker & systemctl enable docker

12、設置開機啟動kubelet

systemctl enable kubelet

13、修改hostname（非常重要，如果hostname相同會導致問題）

hostnamectl set-hostname XXXX

14、初始化Master節點

kubeadm init --kubernetes-version=v1.15.3 --apiserver-advertise-address=10.170.0.7 --pod-network-cidr=10.170.0.0/16 --service-cidr=172.20.0.0/16

現在最新版的為：1.15.3，在執行時，若版本出錯，錯誤的信息中，會提示。

如果出現timeout是因為docker無法自動獲取到images導致的，可以兩種方式解決

• A、手動去pull并修改標簽
• B、修改docker源的方式來解決

15、手動pull images

docker pull mirrorgooglecontainers/kube-apiserver:v1.15.3
docker pull mirrorgooglecontainers/kube-controller-manager:v1.15.3
docker pull mirrorgooglecontainers/kube-scheduler:v1.15.3
docker pull mirrorgooglecontainers/kube-proxy:v1.15.3
docker pull mirrorgooglecontainers/pause:3.1
docker pull mirrorgooglecontainers/etcd:3.2.24
docker pull coredns/coredns:1.2.6
docker tag mirrorgooglecontainers/kube-proxy:v1.13.0  k8s.gcr.io/kube-proxy:v1.15.3
docker tag mirrorgooglecontainers/kube-scheduler:v1.13.0 k8s.gcr.io/kube-scheduler:v1.15.3
docker tag mirrorgooglecontainers/kube-apiserver:v1.13.0 k8s.gcr.io/kube-apiserver:v1.15.3
docker tag mirrorgooglecontainers/kube-controller-manager:v1.15.3 k8s.gcr.io/kube-controller-manager:v1.13.0
docker tag mirrorgooglecontainers/etcd:3.2.24  k8s.gcr.io/etcd:3.2.24
docker tag coredns/coredns:1.2.6 k8s.gcr.io/coredns:1.2.6
docker tag mirrorgooglecontainers/pause:3.1  k8s.gcr.io/pause:3.1

請注意版本號的問題，若是已更新，請相應的變更 。

16、修改docker源

kubeadm init --image-repository="mirrorgooglecontainers"

17、重新執行第15步

18、啟動成功之后可以看到集群已經啟動成功，并且生成了worker加入集群的指令，只要在worker上執行即可加入集群

kubeadm join 10.170.0.7:6443 --token xrhtyd.b61v0mzuu6cea8qg \
    --discovery-token-ca-cert-hash sha256:2e5cb96ef0be0e791acb923cf371303b13bda4613b4fd6d11a59bc17a7f8c3dd 

19、執行如下指令

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

20、這時候輸入kubectl get cs 就可以查看服務的運行情況，確保都在正常運行

21、安裝network addon(采用官方推薦的flannel方案，其中pod網段必須與之前init的時候設置的pod-network-cidr一致)

yum install -y wget
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml && kubectl apply -f  kube-flannel.yml

22、將worker join至master
至此集群已搭建完畢，這時候可以通過kubectl get nodes來查看各節點運行情況

安裝Prometheus
1、在各個節點下載docker對應鏡像

docker pull prom/node-exporter
docker pull prom/prometheus:v2.0.0
docker pull grafana/grafana:4.2.0

2、以daemonset方式部署node-export組件

vi node-exporter.yaml
---
apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: node-exporter
  namespace: kube-system
  labels:
    k8s-app: node-exporter
spec:
  template:
    metadata:
      labels:
        k8s-app: node-exporter
    spec:
      containers:
      - image: prom/node-exporter
        name: node-exporter
        ports:
        - containerPort: 9100
          protocol: TCP
          name: http
---
apiVersion: v1
kind: Service
metadata:
  labels:
    k8s-app: node-exporter
  name: node-exporter
  namespace: kube-system
spec:
  ports:
  - name: http
    port: 9100
    nodePort: 31672
    protocol: TCP
  type: NodePort
  selector:
    k8s-app: node-exporter

kubectl create -f  node-exporter.yaml

3、部署prometheus組件

vi rabc-setup.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: prometheus
rules:
- apiGroups: [""]
  resources:
  - nodes
  - nodes/proxy
  - services
  - endpoints
  - pods
  verbs: ["get", "list", "watch"]
- apiGroups:
  - extensions
  resources:
  - ingresses
  verbs: ["get", "list", "watch"]
- nonResourceURLs: ["/metrics"]
  verbs: ["get"]
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: prometheus
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: prometheus
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: prometheus
subjects:
- kind: ServiceAccount
  name: prometheus
  namespace: kube-system

4、以configmap的形式管理prometheus組件的配置文件

vi configmap.yaml 
apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-config
  namespace: kube-system
data:
  prometheus.yml: |
    global:
      scrape_interval:     15s
      evaluation_interval: 15s
    scrape_configs:

    - job_name: 'kubernetes-apiservers'
      kubernetes_sd_configs:
      - role: endpoints
      scheme: https
      tls_config:
        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
      bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
      relabel_configs:
      - source_labels: [__meta_kubernetes_namespace, __meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name]
        action: keep
        regex: default;kubernetes;https

    - job_name: 'kubernetes-nodes'
      kubernetes_sd_configs:
      - role: node
      scheme: https
      tls_config:
        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
      bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
      relabel_configs:
      - action: labelmap
        regex: __meta_kubernetes_node_label_(.+)
      - target_label: __address__
        replacement: kubernetes.default.svc:443
      - source_labels: [__meta_kubernetes_node_name]
        regex: (.+)
        target_label: __metrics_path__
        replacement: /api/v1/nodes/${1}/proxy/metrics

    - job_name: 'kubernetes-cadvisor'
      kubernetes_sd_configs:
      - role: node
      scheme: https
      tls_config:
        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
      bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
      relabel_configs:
      - action: labelmap
        regex: __meta_kubernetes_node_label_(.+)
      - target_label: __address__
        replacement: kubernetes.default.svc:443
      - source_labels: [__meta_kubernetes_node_name]
        regex: (.+)
        target_label: __metrics_path__
        replacement: /api/v1/nodes/${1}/proxy/metrics/cadvisor

    - job_name: 'kubernetes-service-endpoints'
      kubernetes_sd_configs:
      - role: endpoints
      relabel_configs:
      - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scrape]
        action: keep
        regex: true
      - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scheme]
        action: replace
        target_label: __scheme__
        regex: (https?)
      - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_path]
        action: replace
        target_label: __metrics_path__
        regex: (.+)
      - source_labels: [__address__, __meta_kubernetes_service_annotation_prometheus_io_port]
        action: replace
        target_label: __address__
        regex: ([^:]+)(?::\d+)?;(\d+)
        replacement: $1:$2
      - action: labelmap
        regex: __meta_kubernetes_service_label_(.+)
      - source_labels: [__meta_kubernetes_namespace]
        action: replace
        target_label: kubernetes_namespace
      - source_labels: [__meta_kubernetes_service_name]
        action: replace
        target_label: kubernetes_name

    - job_name: 'kubernetes-services'
      kubernetes_sd_configs:
      - role: service
      metrics_path: /probe
      params:
        module: [http_2xx]
      relabel_configs:
      - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_probe]
        action: keep
        regex: true
      - source_labels: [__address__]
        target_label: __param_target
      - target_label: __address__
        replacement: blackbox-exporter.example.com:9115
      - source_labels: [__param_target]
        target_label: instance
      - action: labelmap
        regex: __meta_kubernetes_service_label_(.+)
      - source_labels: [__meta_kubernetes_namespace]
        target_label: kubernetes_namespace
      - source_labels: [__meta_kubernetes_service_name]
        target_label: kubernetes_name

    - job_name: 'kubernetes-ingresses'
      kubernetes_sd_configs:
      - role: ingress
      relabel_configs:
      - source_labels: [__meta_kubernetes_ingress_annotation_prometheus_io_probe]
        action: keep
        regex: true
      - source_labels: [__meta_kubernetes_ingress_scheme,__address__,__meta_kubernetes_ingress_path]
        regex: (.+);(.+);(.+)
        replacement: ${1}://${2}${3}
        target_label: __param_target
      - target_label: __address__
        replacement: blackbox-exporter.example.com:9115
      - source_labels: [__param_target]
        target_label: instance
      - action: labelmap
        regex: __meta_kubernetes_ingress_label_(.+)
      - source_labels: [__meta_kubernetes_namespace]
        target_label: kubernetes_namespace
      - source_labels: [__meta_kubernetes_ingress_name]
        target_label: kubernetes_name

    - job_name: 'kubernetes-pods'
      kubernetes_sd_configs:
      - role: pod
      relabel_configs:
      - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_scrape]
        action: keep
        regex: true
      - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_path]
        action: replace
        target_label: __metrics_path__
        regex: (.+)
      - source_labels: [__address__, __meta_kubernetes_pod_annotation_prometheus_io_port]
        action: replace
        regex: ([^:]+)(?::\d+)?;(\d+)
        replacement: $1:$2
        target_label: __address__
      - action: labelmap
        regex: __meta_kubernetes_pod_label_(.+)
      - source_labels: [__meta_kubernetes_namespace]
        action: replace
        target_label: kubernetes_namespace
      - source_labels: [__meta_kubernetes_pod_name]
        action: replace
        target_label: kubernetes_pod_name

5、deployment文件

vi prometheus.deploy.yml
apiVersion: apps/v1beta2
kind: Deployment
metadata:
  labels:
    name: prometheus-deployment
  name: prometheus
  namespace: kube-system
spec:
  replicas: 1
  selector:
    matchLabels:
      app: prometheus
  template:
    metadata:
      labels:
        app: prometheus
    spec:
      containers:
      - image: prom/prometheus:v2.0.0
        name: prometheus
        command:
        - "/bin/prometheus"
        args:
        - "--config.file=/etc/prometheus/prometheus.yml"
        - "--storage.tsdb.path=/prometheus"
        - "--storage.tsdb.retention=24h"
        ports:
        - containerPort: 9090
          protocol: TCP
        volumeMounts:
        - mountPath: "/prometheus"
          name: data
        - mountPath: "/etc/prometheus"
          name: config-volume
        resources:
          requests:
            cpu: 100m
            memory: 100Mi
          limits:
            cpu: 500m
            memory: 2500Mi
      serviceAccountName: prometheus    
      volumes:
      - name: data
        emptyDir: {}
      - name: config-volume
        configMap:
          name: prometheus-config

6、Prometheus service文件

vi prometheus.svc.yml
kind: Service
apiVersion: v1
metadata:
  labels:
    app: prometheus
  name: prometheus
  namespace: kube-system
spec:
  type: NodePort
  ports:
  - port: 9090
    targetPort: 9090
    nodePort: 30003
  selector:
    app: prometheus

7、創建文件

kubectl create -f  rbac-setup.yaml
kubectl create -f  configmap.yaml 
kubectl create -f  prometheus.deploy.yml 
kubectl create -f  prometheus.svc.yml