Kubernetes第七曲 Kubernetes支持YAML和JSON格式创建资源对象
- 一、YAML和JSON
- 二、演示yaml
- 三、详解k8s中的port
- 四、自动测试命令的正确性，并不执行创建（--dry-run）
- 五、查看生成yaml格式
- 六、查看生成json格式
- 七、将现有的资源生成模板导出
- 八、保存到文件中
- 九、查看字段帮助信息
一、YAML和JSON
1、概述
Kubernetes支持YAML和JSON格式创建资源对象
JSON格式用于接口之间消息的传递
YAML格式用于配置和管理
YAML是一种简洁的非标记性语言
2、语法格式：
缩进标识层级关系
不支持制表符缩进，使用空格缩进
通常开头缩进两个空格
字符后缩进一个空格，如冒号，逗号，短横杆等
“—”表示YAML格式，一个文件的开始
“#”表示注释
[root@localhost demo]# kubectl api-versions
admissionregistration.k8s.io/v1beta1
apiextensions.k8s.io/v1beta1
apiregistration.k8s.io/v1
apiregistration.k8s.io/v1beta1
apps/v1
apps/v1beta1
apps/v1beta2
authentication.k8s.io/v1
authentication.k8s.io/v1beta1
authorization.k8s.io/v1
authorization.k8s.io/v1beta1
autoscaling/v1
autoscaling/v2beta1
autoscaling/v2beta2
batch/v1
batch/v1beta1
certificates.k8s.io/v1beta1
coordination.k8s.io/v1beta1
events.k8s.io/v1beta1
extensions/v1beta1
networking.k8s.io/v1
policy/v1beta1
rbac.authorization.k8s.io/v1
rbac.authorization.k8s.io/v1beta1
scheduling.k8s.io/v1beta1
storage.k8s.io/v1
storage.k8s.io/v1beta1
v1
二、演示yaml
1、编写yaml文件
[root@localhost ~]# mkdir demo #创建一个专门的目录
[root@localhost ~]# cd demo/
[root@localhost demo]# vim nginx-deployment.yaml #编写yaml文件
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
labels:
app: nginx
spec:
replicas: 3
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.15.4
ports:
- containerPort: 80
2、创建资源，kind种类为deployment
[root@localhost demo]# kubectl create --help
Usage:
kubectl create -f FILENAME [options]
[root@localhost demo]# kubectl create -f nginx-deployment.yaml #创建资源
deployment.apps/nginx-deployment created
[root@localhost demo]# kubectl get pods #查看创建的资源
NAME READY STATUS RESTARTS AGE
nginx-7697996758-75shs 1/1 Running 0 21h
nginx-7697996758-b7tjw 1/1 Running 0 21h
nginx-7697996758-jddc5 1/1 Running 0 21h
nginx-deployment-d55b94fd-4px2w 1/1 Running 0 2m13s
nginx-deployment-d55b94fd-899hz 1/1 Running 0 2m13s
nginx-deployment-d55b94fd-d7fqn 1/1 Running 0 2m13s
3、编写service的yaml
[root@localhost demo]# vim nginx-service.yaml
apiVersion: v1
kind: Service
metadata:
name: nginx-service
labels:
app: nginx
spec:
type: NodePort
ports:
- port: 80
targetPort: 80
selector:
app: nginx
[root@localhost demo]# kubectl create -f nginx-service.yaml
service/nginx-service created
[root@localhost demo]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.0.0.1 <none> 443/TCP 13d
nginx-service NodePort 10.0.0.225 <none> 80:47722/TCP 23s
三、详解k8s中的port
port
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
nodePort
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。
targetPort
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。
containerPort
containerPort是pod内部容器的端口，targetPort映射到containerPort。
四、自动测试命令的正确性，并不执行创建（–dry-run）
[root@localhost demo]# kubectl run nginx-deployment --image=nginx --port=80 --replicas=3 --dry-run
kubectl run --generator=deployment/apps.v1beta1 is DEPRECATED and will be removed in a future version. Use kubectl create instead.
deployment.apps/nginx-deployment created (dry run)
五、查看生成yaml格式
[root@localhost demo]# kubectl run nginx-deployment --image=nginx --port=80 --replicas=3 --dry-run -o yaml
六、查看生成json格式
[root@localhost demo]# kubectl run nginx-deployment --image=nginx --port=80 --replicas=3 --dry-run -o json
#也可以> 导出到一个新文件
[root@localhost demo]# kubectl run nginx-deployment --image=nginx --port=80 --replicas=3 --dry-run -o yaml > my-deployment.yaml
kubectl run --generator=deployment/apps.v1beta1 is DEPRECATED and will be removed in a future version. Use kubectl create instead.
[root@localhost demo]# ls
my-deployment.yaml nginx-deployment.yaml nginx-service.yaml
七、将现有的资源生成模板导出
[root@localhost demo]# kubectl get deploy/nginx --export -o yaml
八、保存到文件中
[root@localhost demo]# kubectl get deploy/nginx --export -o yaml > my-deploy.yaml
九、查看字段帮助信息
[root@localhost demo]# kubectl explain pods.spec.containers