k8s基础

1.各组件作用及部署

Master组件：

kube-apiserver：集群统一入口，各组件协调者，以HTTP API 提供接口服务，所有对象资源的增删改查和监听操作都交给APIServer处理后再提交给etcd存储

kube-controller-manager：处理集群中常规后台任务，一个资源对应一个控制器，而ControllerManager就是负责管理这些控制器的。

kube-scheduler：根据调度算法为新创建的Pod选择一个Node节点。

Node组件：

kubelet：是master在node节点上的Agent，管理本机运行容器的生命周期，比如创建容器、Pod挂载卷、下载servret、获取容器和节点状态等工作。kubelet将每个Pod转换成一组容器。

kube-proxy：在Node节点上实现Pod网络代理，维护网络规划和四层负载均衡工作

自动化部署：参考 https://github.com/unixhot/salt-kubernetes

2.使用pod管理容器

docker pull nginx:1.13.12 ##从docker仓库拉取nginx镜像

docker pull nginx:1.14.0 ##从docker仓库拉取nginx镜像

docker login 192.168.56.11 ##登录harbor

docker tag nginx:1.13.12 192.168.56.11/devopsedu/nginx:1.13.12 ##给镜像打标签

docker push 192.168.56.11/devopsedu/nginx:1.13.12 ##把镜像推送到harbor上

配置yaml不能用tab键，注意缩进

- 表示列表

： key value

harbor秘钥配置

cat /root/.docker/config.json |base64 #对harbor密码进行编码

cat harbor-secret.yaml 内容如下：

apiVersion: v1
kind: Secret
metadata:
  name: harbor-secret
  namespace: default
data:
  .dockerconfigjson: ewoJImF1dGhzIjogewoJCSIxOTIuMTY4LjU2LjExIjogewoJCQkiYXV0aCI6ICJZV1J0YVc0NlNHRnlZbTl5TVRJek5EVT0iCgkJfQoJfSwKCSJIdHRwSGVhZGVycyI6IHsKCQkiVXNlci1BZ2VudCI6ICJEb2NrZXItQ2xpZW50LzE4LjA5LjAgKGxpbnV4KSIKCX0KfQ==
type: kubernetes.io/dockerconfigjson

kubectl create -f harbor-secret.yaml ##创建秘钥

配置pod.yaml,内容如下：

apiVersion: v1    #版本号
kind: Pod     #Pod方法，资源对象类型
metadata:        #元数据
  name: nginx-pod    #metadata.name Pod的名称
  labels:                   #自定义标签列表
    app: nginx
spec:                        # Pod中容器的详细定义
  containers:              #容器列表
  - name: nginx         #容器名称
    image: 192.168.56.11/devopsedu/nginx:1.13.12   #容器镜像名称
    ports:                                      #容器需要暴露的端口列表
    - containerPort: 80
  imagePullSecrets:
    - name: harbor-secret               #引用harbor秘钥

kubectl create -f nginx-pod.yaml #创建pod　　

kubectl get pod #获取pod

kubectl get pod -o wide #获取pod详细信息

kubectl describe pod nginx-pod #查看pod详细情况

kubectl delete pod nginx-pod #删除pod

3.使用RC管理pod

RC（Replication Contorller）：监控pod，保证pod高可用，指定并管理副本

rc.yaml配置如下

cat nginx-rc.yaml

apiVersion: v1
kind: ReplicationController
metadata:
  name: nginx-rc
spec:
  replicas: 3
  selector:
    app: nginx
  template:
    metadata:
      name: nginx
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: 192.168.56.11/devopsedu/nginx:1.13.12
        ports:
        - containerPort: 80
      imagePullSecrets:
        - name: harbor-secret

kubectl create -f nginx-rc.yaml #创建rc

kubectl get rc -o wide ##获取rc

kubectl describe rc ##查看rc详细信息

kubectl scale rc nginx-rc --replicas=4 #指定rc副本数量

kubectl rolling-update nginx-rc --image=192.168.56.11/devopsedu/nginx:1.14.0 #滚动升级容器

使用RS和Deployment管理pod

Deployment表示对k8s集群的一次性操作，比rs应用模式更广的api对象，对rs有做一层封装

rs配置如下：

apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: nginx-rs
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      name: nginx
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: 192.168.56.11/devopsedu/nginx:1.13.12
        ports:
        - containerPort: 80
      imagePullSecrets:
        - name: harbor-secret

cat nginx-deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      name: nginx
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: 192.168.56.11/devopsedu/nginx:1.13.12
        ports:
        - containerPort: 80
      imagePullSecrets:
        - name: harbor-secret

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kubectl create -f nginx-deployment.yaml --record #创建并记录创建过程

kubectl get deploy #获取deployment

kubectl get pod --show-labels #查看pod标签

kubectl set image deployment/nginx-deployment nginx=192.168.56.11/devopsedu/nginx:1.14.0 #更新镜像

kubectl rollout history deployment/nginx-deployment #查看版本更详细历史

kubectl rollout history deployment/nginx-deployment --revision=1 #查看第一个版本的执行明细

kubectl rollout undo deployment/nginx-deployment ##回滚到上一版本

kubectl rollout undo deployment/nginx-deployment --to-revision=2 ##回滚到指定版本

kubectl scale deployment nginx-deployment --replicas 5 ##扩容

kubectl scale deployment nginx-deployment --replicas 2 ##缩容

DaemonSet管理pod和node Labels

Daemonset确保每个node运行一个pod副本，当有集群增加或减少时，也会增加或减少pod副本

yaml配置：

 1 apiVersion: apps/v1
 2 kind: DaemonSet
 3 metadata:
 4   name: nginx-daemonset
 5   labels:
 6     app: nginx
 7 spec:
 8   selector:
 9     matchLabels:
10       app: nginx
11   template:
12     metadata:
13       labels:
14         app: nginx
15     spec:
16       containers:
17       - name: nginx
18         image: nginx:1.13.12
19         ports:
20         - containerPort: 80

当需要指定node是，添加

nodeSelector:
disktype: ssd

和containers同级。

kubectl create -f daemonset nginx-daemonset.yaml ##创建daemonset

Node Selector操作：使pod运行在指定的node上

kubectl label nodes 192.168.56.13 disktype=ssd #先给指定node打标签

kubectl get nodes --show-labels #查看node标签

service管理pod访问

ip是固定的

kind: Service
apiVersion: v1
metadata:
  name: nginx-service
spec:
  selector:
    app: nginx
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80

kubectl create -f nginx-service.yaml

kubectl get service

kubectl apply -f nginx-service.yaml ##重新应用(加载)

通常情况下，deployment和service一块创建，配置如下：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      name: nginx
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: 192.168.56.11/devopsedu/nginx:1.13.12
        ports:
        - containerPort: 80
      imagePullSecrets:
        - name: harbor-secret




kind: Service
apiVersion: v1
metadata:
  name: nginx-service
spec:
  selector:
    app: nginx
  ports:
  - name: http
    protocol: TCP
    port: 80
    targetPort: 80
  - name: https
    protocol: TCP
    port: 443
    targetPort: 80

在下面跟ports同级加上type: NodePort 就能通过node + IP:端口访问了。 http://192.168.56.12:20046

使用Traefik实现Ingress

service只能实现4层 ip+端口的形式访问，如果要实现7层的访问，就要用到ingress。

kubectl label nodes 192.168.56.12 edgenode=true #打标签

kubectl get nodes --show-lables ##获取标签

kubectl create -f /srv/addons/ingress/ #创建traefik

ingress目录配置如下：

 1 #cat daemonset.yml 
 2 apiVersion: extensions/v1beta1
 3 kind: DaemonSet
 4 metadata:
 5   name: traefik-ingress-lb
 6   namespace: kube-system
 7   labels:
 8     k8s-app: traefik-ingress-lb
 9 spec:
10   template:
11     metadata:
12       labels:
13         k8s-app: traefik-ingress-lb
14         name: traefik-ingress-lb
15     spec:
16       terminationGracePeriodSeconds: 60
17       hostNetwork: true
18       restartPolicy: Always
19       serviceAccountName: ingress
20       containers:
21       - image: traefik:v1.6
22         name: traefik-ingress-lb
23         resources:
24           limits:
25             cpu: 200m
26             memory: 80Mi
27           requests:
28             cpu: 100m
29             memory: 50Mi
30         ports:
31         - name: http
32           containerPort: 80
33           hostPort: 80
34         - name: admin
35           containerPort: 8580
36           hostPort: 8580
37         args:
38         - --web
39         - --web.address=:8580
40         - --kubernetes
41       nodeSelector:
42         edgenode: "true"
43 
44 #cat ingress-rbac.yml 
45 apiVersion: v1
46 kind: ServiceAccount
47 metadata:
48   name: ingress
49   namespace: kube-system
50 
51 ---
52 
53 kind: ClusterRoleBinding
54 apiVersion: rbac.authorization.k8s.io/v1beta1
55 metadata:
56   name: ingress
57 subjects:
58   - kind: ServiceAccount
59     name: ingress
60     namespace: kube-system
61 roleRef:
62   kind: ClusterRole
63   name: cluster-admin
64   apiGroup: rbac.authorization.k8s.io
65 
66 #cat traefik-ui.yml 
67 apiVersion: v1
68 kind: Service
69 metadata:
70   name: traefik-web-ui
71   namespace: kube-system
72 spec:
73   selector:
74     k8s-app: traefik-ingress-lb
75   ports:
76   - name: web
77     port: 80
78     targetPort: 8580
79 ---
80 apiVersion: extensions/v1beta1
81 kind: Ingress
82 metadata:
83   name: traefik-web-ui
84   namespace: kube-system
85 spec:
86   rules:
87   - host: traefik-ui.local
88     http:
89       paths:
90       - path: /
91         backend:
92           serviceName: traefik-web-ui
93           servicePort: web

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kubectl create -f nginx-ingress.yaml #创建ingress

nginx-ingress.yaml配置如下：

 1 apiVersion: extensions/v1beta1
 2 kind: Ingress
 3 metadata:
 4   name: nginx-ingress
 5 spec:
 6   rules:
 7   - host: www.example.com
 8     http:
 9       paths:
10       - path: /
11         backend:
12           serviceName: nginx-service
13           servicePort: 80

绑定hosts，访问www.example.com即可。

posted @ 2019-02-15 15:38 liumj 阅读(318) 评论(0) 编辑收藏举报

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