1, Environment preparation: MiniKube+Docker:

Recently, I began to try to learn and understand k8s, and the purpose of writing this article is to make a record,
Learn through exploration. Welcome to visit and exchange.

1. Install Docker:

Continue the simple packaged deployment series with IDEA+Docker

2. Install the MiniKube:

Minikube is a local Kubernetes that focuses on making Kubernetes easy to learn and develop. Official document: [minikube official installation document]

2, Preparation:

Create yaml file:

vi deployment.yaml

Configuration content:

apiVersion: apps/v1
kind: Deployment # Configuration type
metadata:
  name: getway-server # Project name to deploy
  labels:
    app: getway-app # Item label
spec: # Specification parameters
  # replicas: 2 # Indicates a Pod with two docker demos
  selector:
    matchLabels:
      app: getway-app
  template:
    metadata:
      labels:
        app: getway-app
    spec:
      containers:
        - name:  getway  # Container name
          # image: getway:v1.0 # Image name:tag # Local warehouse
          image: registry.cn-chengdu.aliyuncs.com/xx/xx:getway-v1.0 # Remote warehouse
          imagePullPolicy: IfNotPresent #Never only uses local images. Always downloads images every time, IfNotPresent 	 Give priority to using local instead of downloading
          ports:
            - containerPort: 3010 # Container port
---
apiVersion: v1
kind: Service # Configuration type
metadata:
  name: getway-service # Name of the service
  # namespace: demo # Namespace kubectl create namespace demo
spec: # Specification parameters
  ports:
    - port: 3010 # Cluster internal access Service port number
      protocol: TCP
      # nodePort: 30001 # Cluster external access Service port number
      targetPort: 3010 # Pod port number
  type: LoadBalancer # Four types: LoadBalance, ExternalName, NodePort and ClusterIP
  selector:
    app: getway-app # The name of the Pod managed by the Server

The image used in k8s deployment can be a local image or a remote image pulled from the image warehouse.

1. Use local image: after packaging the image, you need to push the image to the Docker registry of Minikube; (Minikube is a stand-alone version k8s. If the cluster does not recommend using local image, it is inconvenient to ensure that each node must have this image.)
2. Use remote warehouse: for example, alicloud image warehouse. Remote image warehouse is divided into public image and private image. If you use private images, you also need to configure ca certificates in the k8s cluster. You do not need to use a public image.

The following are two ways of using local image and remote public image

1. Use local image:

Save the target image locally first

  docker save [REPOSITORY]:[TAG] > xx.tar

Docker registry of Minikube (can be understood as k8s internal docker)

 eval $(minikube docker-env)

Load docker mirrored to k8s internal

docker load < xx.tar 

Configuration of local image in yaml file

containers:
  - name:  getway  # Container name
     image: getway:v1.0 # Image name:tag # Local warehouse
     #image: registry.cn-chengdu.aliyuncs.com/xx/xx:getway-v1.0 # Remote warehouse
     imagePullPolicy: Never #Never only uses the local image. Always downloads the image every time. IfNotPresent gives priority to using the local image instead of downloading it
     ports:
       - containerPort: 3010 # Container port

2. Use image warehouse:

Configuration of remote warehouse image in yaml

containers:
  - name:  getway  # Container name
    # image: getway:v1.0 # Image name:tag # Local warehouse
    image: registry.cn-chengdu.aliyuncs.com/xx/xx:getway-v1.0 # Remote warehouse
    imagePullPolicy: IfNotPresent #Never only uses the local image. Always downloads the image every time. IfNotPresent gives priority to the local image and does not download it again
    ports:
      - containerPort: 3010 # Container port

3, Start:

Execution profile

kubectl apply -f vi deployment.yaml

Check the operation of Pod

kubectl get pod -o wide

Or use the dashboard that comes with Minikube to execute the command

minikube dashboard

4, Test:

1. View all services

kubectl get svc

2. Temporary opening to the outside world

minikube service getway-service --url

After the command is executed, k8s a random port number will be temporarily opened for external access. A wave of tests can be performed using the following URL.

5, Several ways to expose services:

Several ways of k8s external exposure services:

1. ClusterIp:

The private ip inside the cluster is very convenient to access services inside the cluster. It is the default mode of kuberentes cluster, but it is inaccessible outside the cluster.

2. NodePort:

To enable the external to directly access the service, you need to modify the service type to nodePort, specify nodePort, and map the service listening port to the node node.
(nodePort port range: 30000-32767)

spec: # Specification parameters                             
  ports:                                 
    - port: 3010 # Cluster internal access Service port number      
      protocol: TCP                      
      nodePort: 30001 # Cluster external access Service port number 
      targetPort: 3010 # Pod port number          
  type: NodePort # Four types: LoadBalance, ExternalName, NodePort and ClusterIP
  selector:                              
    app: getway-app # The name of the Pod managed by the Server   

3. LoadBalance:

  ports:                                                                
    - port: 3010 #Cluster internal access Service port number                                     
      protocol: TCP                                                                                  
      targetPort: 3010 # Pod port number                                         
  type: LoadBalancer # Four types: LoadBalance, ExternalName, NodePort and ClusterIP 

During the above test, check all Services, and you can see that the EXTERNAL-IP of the Getway service is in the state. Then execute the following command.

minikube tunnel

At this time, the dashborad view Service has exposed the IP:Port required for external access
Test with PostMan:

4. Ingress:

Friendship connection between Ingress and Ingress Controller