apiVersion: v1           # Kubernetes API 的版本，对于 Pod 来说，通常是 v1  
kind: Pod                # 要创建的对象的类别，这里是 Pod  
metadata:  
  name: my-pod           # 对象的名称，在命名空间中必须是唯一的  
  namespace: default     # 命名空间，如果省略，则默认为 default  
                         # UID 是由 Kubernetes 系统自动生成的，不需要在清单文件中指定  
spec:  
  containers:            # Pod 规格中定义了容器的列表  
  - name: my-container   # 容器的名称  
    image: nginx:1.19.2  # 容器使用的镜像及其标签  
                         # 其他容器配置，如端口、环境变量等...

# 这是一个注释
person:  # 字典的开始
  name: John Doe  # 字符串
  age: 30  # 整数
  married: true  # 布尔值
  children:  # 列表的开始
    - name: Jane Doe
      age: 10
    - name: Doe Junior
      age: 5

kubectl explain deployment
KIND:     Deployment
VERSION:  apps/v1

DESCRIPTION:
     Deployment enables declarative updates for Pods and ReplicaSets.

FIELDS:
   apiVersion  <string>
     APIVersion defines the versioned schema of this representation of an
     object. Servers should convert recognized schemas to the latest internal
     value, and may reject unrecognized values. More info:
     https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources

   kind  <string>
     Kind is a string value representing the REST resource this object
     represents. Servers may infer this from the endpoint the client submits
     requests to. Cannot be updated. In CamelCase. More info:
     https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds

   metadata  <Object>
     Standard object's metadata. More info:
     https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata

   spec  <Object>
     Specification of the desired behavior of the Deployment.

   status  <Object>
     Most recently observed status of the Deployment.

kubectl create deployment jumpoint-web --image=nginx:latest --port=80 --replicas=2 --namespace=jumpoint-ns --dry-run=client --output=yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: jumpoint-web
  name: jumpoint-web
  namespace: jumpoint-ns
spec:
  replicas: 2
  selector:
    matchLabels:
      app: jumpoint-web
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: jumpoint-web
    spec:
      containers:
      - image: nginx:latest
        name: nginx
        ports:
        - containerPort: 80
        resources: {}
status: {}

#若要查看metadata.labels字段的含义

kubectl explain deployment.metadata.labels
KIND:     Deployment
VERSION:  apps/v1

FIELD:    labels <map[string]string>

DESCRIPTION:
     Map of string keys and values that can be used to organize and categorize
     (scope and select) objects. May match selectors of replication controllers
     and services. More info: http://kubernetes.io/docs/user-guide/labels

#若要查看spec.selector.matchLabels字段的含义（其它字段含义查询方式类似）

kubectl explain deployment.spec.selector.matchLabels
KIND:     Deployment
VERSION:  apps/v1

FIELD:    matchLabels <map[string]string>

DESCRIPTION:
     matchLabels is a map of {key,value} pairs. A single {key,value} in the
     matchLabels map is equivalent to an element of matchExpressions, whose key
     field is "key", the operator is "In", and the values array contains only
     "value". The requirements are ANDed.

#若要查看deployment.spec.template.spec.containers字段下还有哪些字段可用，有时可能要根据实际需求添加一些字段（上边生成的YAML文件略简单）

kubectl explain deployment.spec.template.spec.containers
KIND:     Deployment
VERSION:  apps/v1

RESOURCE: containers <[]Object>

DESCRIPTION:
     List of containers belonging to the pod. Containers cannot currently be
     added or removed. There must be at least one container in a Pod. Cannot be
     updated.

     A single application container that you want to run within a pod.

FIELDS:
...
   imagePullPolicy  <string>
     Image pull policy. One of Always, Never, IfNotPresent. Defaults to Always
     if :latest tag is specified, or IfNotPresent otherwise. Cannot be updated.
     More info:
     https://kubernetes.io/docs/concepts/containers/images#updating-images

     Possible enum values:
     - `"Always"` means that kubelet always attempts to pull the latest image.
     Container will fail If the pull fails.
     - `"IfNotPresent"` means that kubelet pulls if the image isn't present on
     disk. Container will fail if the image isn't present and the pull fails.
     - `"Never"` means that kubelet never pulls an image, but only uses a local
     image. Container will fail if the image isn't present
...

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: jumpoint-web-deployment-label
  name: jumpoint-web
  namespace: jumpoint-ns
spec:
  replicas: 2
  selector:
    matchLabels:
      app: jumpoint-web-pod-label
  template:
    metadata:
      labels:
        app: jumpoint-web-pod-label
    spec:
      containers:
      - image: nginx:latest
        name: jumpoint-web-container-name
        imagePullPolicy: Always
        ports:
        - containerPort: 80
          protocol: TCP
          name: http

#使用nginx-deployment.yaml文件创建Deployment资源对象。


kubectl create namespace jumpoint-ns

kubectl apply -f nginx-deployment.yaml

kubectl get deployments -n jumpoint-ns

kubectl get pods -n jumpoint-ns -o wide

kubectl describe deployment -n jumpoint-ns jumpoint-web