yaml文件及语法基础

Posted 2022-04-21 小怪獣55

在线yaml与json编辑器:​​https://www.bejson.com/validators/yaml_editor/​​

1.yaml格式特点

1. 大小写敏感
2. 使用缩进表示层级关系
3. 缩进时不允许使用Tal键,只允许使用空格
4. 缩进的空格数目不重要,只要相同层级的元素左侧对齐即可
5. 使用"#" 表示注释,从这个字符一直到行尾,都会被解析器忽略
6. 比json更适用于配置文件

2.yaml文件详解

kind: Deployment                          #类型,是deployment控制器,kubectl explain Deployment
apiVersion: extensions/v1beta1            #API版本,# kubectl explain Deployment.apiVersion

metadata:                                 #pod的元数据信息,kubectl explain Deployment.metadata
  labels:                                 #自定义pod的标签,# kubectl explain Deployment.metadata.labels
    app: linux36-nginx-deployment-label   #标签名称为app,值为linux35-nginx,后面会用到此标签
  name: linux36-nginx-deployment          #pod的名称
  namespace: linux36                      #pod的namespace,默认是defaule

spec:                                     #定义deployment中容器的详细信息,kubectl explain Deployment.spec
  replicas: 1                             #创建出的pod的副本数,即多少个pod,默认值为1
  selector:                               #定义标签选择器
    matchLabels:                          #定义匹配的标签,必须要设置
      app: linux36-nginx-selector         #匹配的目标标签

  template:                               #定义模板,必须定义,模板是起到描述要创建的pod的作用
    metadata:                             #定义模板元数据
      labels:                             #定义模板label,Deployment.spec.template.metadata.labels
        app: linux36-nginx-selector       #定义标签,等于
    spec:                               #定义pod信息
      containers:                         #定义pod中容器列表,可以多个至少一个,pod不能动态增减容器
      - name: linux36-nginx-container     #容器名称
        image: harbor.magedu.net/linux36/nginx-web1:2019-08-03_18_26_52 #镜像地址
        #command: ["/apps/tomcat/bin/run_tomcat.sh"]                    #容器启动执行的命令或脚本
        #imagePullPolicy: IfNotPresent
        imagePullPolicy: Always #拉取镜像策略
        ports:                #定义容器端口列表
        - containerPort: 80     #定义一个端口
          protocol: TCP         #端口协议
          name: http            #端口名称
        - containerPort: 443
          protocol: TCP
          name: https
        env:                  #配置环境变量
        - name: "password"      #变量名称。必须要用引号引起来
          value: "123456"       #当前变量的值
        - name: "age"
          value: "18"
        resources:          #对资源的请求设置和限制设置
          limits:             #资源限制设置,上限
            cpu: 2              #cpu的限制,单位为core数,将用于docker run --cpu-shares参数
            memory: 2Gi         #内存限制,单位可以为Mib/Gib,将用于docker run --memory参数
          requests:           #资源请求的设置
            cpu: 500m           #cpu请求数,容器启动的初始可用数量,可以写0.5或者500m等CPU压缩值
            memory: 1Gi         #内存请求大小,容器启动的初始可用数量,用于调度pod时候使用

        volumeMounts:
        - name: linux36-images
          mountPath: /usr/local/nginx/html/webapp/images
          readOnly: false
        - name: linux36-static
          mountPath: /usr/local/nginx/html/webapp/static
          readOnly: false
      volumes:
      - name: linux36-images
        nfs:
          server: 192.168.7.108
          path: /data/k8sdata/linux36/images 
      - name: linux36-static
        nfs:
          server: 192.168.7.108
          path: /data/k8sdata/linux36/static

---
kind: Service        #类型为service
apiVersion: v1 v1    #service API版本, service.apiVersion

metadata:            #定义service元数据,service.metadata
  labels:            #自定义标签,service.metadata.labels
    app: linux36-nginx-service-label  #定义service标签的内容
  name: linux36-nginx-service         #定义service的名称,此名称会被DNS解析
  namespace: linux36 #该service隶属于的namespaces名称,即把service创建到哪个namespace里面

spec:              #定义service的详细信息,service.spec
  type: NodePort     #service的类型,定义服务的访问方式,默认为ClusterIP, service.spec.type
  ports:             #定义访问端口, service.spec.ports
  - name: http
    port: 80
    protocol: TCP
    targetPort: 80   #目标pod的端口
    nodePort: 30002  #node节点暴露的端口
  - name: https
    port: 443
    protocol: TCP
    targetPort: 443
    nodePort: 30443
  selector:                                   #service的标签选择器,定义要访问的目标pod
    app: linux36-nginx-selector               #将流量路到选择的pod上,须等于Deployment.spec.selector.matchLabels

3.创建业务namespace

cat linux36.yaml
------------------------------------
apiVersion: v1    #API版本
kind: Namespace   #类型为namespac
metadata:         #定义元数据
  name: linux36   #namespace名称
------------------------------------

kubectl apply -f linux36.yaml
kubectl get namespaces

4.创建Nginx pod 并测试通过node port访问

kind: Deployment
apiVersion: extensions/v1beta1
metadata:
  labels:
    app: linux36-nginx-deployment-label
  name: linux36-nginx-deployment
  namespace: linux36
spec:
  replicas: 1
  selector:
    matchLabels:
      app: linux36-nginx-selector
  template:
    metadata:
      labels:
        app: linux36-nginx-selector
    spec:
      containers:
      - name: linux36-nginx-container
        image: harbor.magedu.net/linux36/nginx-web1:2019-08-03_18_26_52
        #command: ["/apps/tomcat/bin/run_tomcat.sh"]
        #imagePullPolicy: IfNotPresent
        imagePullPolicy: Always
        ports:
        - containerPort: 80
          protocol: TCP
          name: http
        - containerPort: 443
          protocol: TCP
          name: https
        env:
        - name: "password"
          value: "123456"
        - name: "age"
          value: "18"
        resources:
          limits:
            cpu: 2
            memory: 2Gi
          requests:
            cpu: 500m
            memory: 1Gi

        volumeMounts:
        - name: linux36-images
          mountPath: /usr/local/nginx/html/webapp/images
          readOnly: false
        - name: linux36-static
          mountPath: /usr/local/nginx/html/webapp/static
          readOnly: false
      volumes:
      - name: linux36-images
        nfs:
          server: 192.168.7.108
          path: /data/k8sdata/linux36/images 
      - name: linux36-static
        nfs:
          server: 192.168.7.108
          path: /data/k8sdata/linux36/static
---
kind: Service
apiVersion: v1
metadata:
  labels:
    app: linux36-nginx-service-label
  name: linux36-nginx-service
  namespace: linux36
spec:
  type: NodePort
  ports:
  - name: http
    port: 80
    protocol: TCP
    targetPort: 80
    nodePort: 30002
  - name: https
    port: 443
    protocol: TCP
    targetPort: 443
    nodePort: 30443
  selector:
    app: linux36-nginx-selector

4.1测试访问

root@k8s-master1:~# ss -ntl |grep 300
LISTEN   0         128                        *:30002                  *:*

http://192.168.47.113:30002/webapp/