Examples

部署nginx

kubectl create deployment hello-nginx --image=nginx

查看dashboard

暴露服务（NodePort）

NodePort, as the name implies, opens a specific port, and any traffic that is sent to this port is forwarded to the service.

The network is limited if using the Docker driver on Darwin, Windows, or WSL, and the Node IP is not reachable directly.

Running minikube on Linux with the Docker driver will result in no tunnel being created.

kubectl expose deployment hello-nginx --type=NodePort --port=80

# Check Node Port
kubectl get services hello-nginx

# Run service tunnel
minikube service hello-nginx

浏览器访问 http://127.0.0.1:60324/

或者自定义转发

kubectl port-forward service/hello-nginx 8020:80

浏览器访问 http://localhost:8020/

暴露服务（LoadBalancer）

each service gets its own IP address.

kubectl create deployment balanced --image=nginx

# 这里没写target-port，默认和port一样是80
kubectl expose deployment balanced --type=LoadBalancer --port=80

minikube tunnel

浏览器访问 http://127.0.0.1:80/

换个端口

kubectl expose deployment balanced --type=LoadBalancer --port=8030 --target-port=80 --name=balanced-8030

minikube tunnel

暴露服务（Ingress）

先启用 ingress 插件

minikube addons enable ingress

kubectl apply -f https://storage.googleapis.com/minikube-site-examples/ingress-example.yaml

yaml文件内容如下：

kind: Pod
apiVersion: v1
metadata:
  name: foo-app
  labels:
    app: foo
spec:
  containers:
    - name: foo-app
      image: 'kicbase/echo-server:1.0'
---
kind: Service
apiVersion: v1
metadata:
  name: foo-service
spec:
  selector:
    app: foo
  ports:
    - port: 8080
---
kind: Pod
apiVersion: v1
metadata:
  name: bar-app
  labels:
    app: bar
spec:
  containers:
    - name: bar-app
      image: 'kicbase/echo-server:1.0'
---
kind: Service
apiVersion: v1
metadata:
  name: bar-service
spec:
  selector:
    app: bar
  ports:
    - port: 8080
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
spec:
  rules:
    - http:
        paths:
          - pathType: Prefix
            path: /foo
            backend:
              service:
                name: foo-service
                port:
                  number: 8080
          - pathType: Prefix
            path: /bar
            backend:
              service:
                name: bar-service
                port:
                  number: 8080
---

其中包含了两个Pod和两个Service的定义，以及一个Ingress资源。这些资源共同定义了一个简单的Kubernetes应用程序，其中有两个应用（foo-app和bar-app）分别通过两个Service（foo-service和bar-service）暴露，并且通过Ingress资源可以根据URL路径（/foo和/bar）来路由到相应的服务。

kubectl get ingress

minikube tunnel

因为 balanced 这个服务占用了80端口，所以访问 localhost/foo 会遇到 404。删掉这个服务再访问。

Scale

kubectl scale deployments/hello-nginx --replicas=3

There are several ways to set environment variables for a Docker container in Kubernetes, including: Dockerfile, kubernetes.yml, Kubernetes ConfigMaps, and Kubernetes Secrets.

ConfigMaps and Secrets is that they can be re-used across multiple containers