k8s yaml资源清单格式

k8s由于资源比较多，组合起来参数众多，不适合用cli传参的形式。 因此用yaml文件的形式传参给k8s。 yaml文件相当于剧本，运维人员相当于制片人，k8s相当于导演，docker相当于剧务、pod详单于演员

pod的资源清单格式：

pod.yaml

apiVersion: v1
kind: Pod
metadata:
  name: my-pod
  namespace: default
  labels:
    app: myapp
spec:
  containers:
  - name: myapp-1
    image: busybox:latest
  - name: myapp-2
    image: busybox:latest
    command:
    - "/bin/sh"
    - "-c"
    - "sleep 10"

创建资源：

kubectl apply -f pod.yaml

deployments的资源清单格式：

apiVersion: # 可以通过cli获取：kubectl  api-resources |grep [deployments|svc|pods]
kind: Deployment # 资源类型：Deployment|Pods|Ingress|Services|...
metadata: # 资源元数据
  name: my-nginx # 资源名称
  namespace: default
  labels:
    app: my-nginx
spec:
  selector: # 标签选择器
    matchLabels:
      app: my-nginx # 选择带有my-nginx标签的资源
  replicas: 2 # 副本数
  template: # 副本模板。模板的内容（除了不需要apiVersion、kind之外，其它子字段都需要定义）
    metadata:
      labels:
        app: my-nginx
    spec:
      containers:
      - name: my-nginx
        image: nginx
        ports:
        - containerPort: 80
        volumeMounts:
          - mountPath: /etc/nginx/nginx.conf
            name: nginx
            subPath: nginx.conf
      volumes:
        - name: nginx
          configMap:
            name: nginx-configmap
            items:
              - key: nginx_conf
                path: nginx.conf

service的yaml清单格式：

apiVersion: networking.k8s.io/v1
kinf: Ingress
metadata:
  name: ingress-entry
spec:
  backend:
    serviceName: nginx-service
    servicePort: 80

---
apiVersion: v1
kind: Service
metadata:
  name: nginx-service  #定义service名称为nginx-service
  labels:
    app: nginx-service   #为service打上app标签
spec:
  type: NodePort   #使用NodePort方式开通，在每个Node上分配一个端口作为外部访问入口
  selector:
    app: my-nginx
  ports:
  - port: 8000  #port是k8s集群内部访问service的端口，即通过clusterIP: port可以访问到某个service
    targetPort: 80  #targetPort是pod的端口，从port和nodePort来的流量经过kube-proxy流入到后端pod的targetPort上，最后进入容器
    nodePort: 32500  #nodePort是外部访问k8s集群中service的端口，通过nodeIP: nodePort可以从外部访问到某个service

configmap的资源清单格式：

apiVersion: v1
kind: ConfigMap
metadata:
  name: nginx-configmap
data:
  nginx_conf: |-
    #user  nobody;
    worker_processes  1;
    events {
        worker_connections  1024;
    }
    http {
        include       mime.types;
        default_type  application/octet-stream;
        sendfile        on;
        keepalive_timeout  65;
        server {
            listen       80;
            server_name  localhost;
            location / {
                root   html;
                index  index.html index.htm;
            }
            error_page   500 502 503 504  /50x.html;
            location = /50x.html {
                root   html;
            }
        }
    }