mysql small example

1. Create a mysql-rc.yaml file

apiVersion: v1
kind: ReplicationController # Replica controller RC
metadata:
  name: mysql # Name of RC, globally unique
spec:
  replicas: 1 # Expected number of copies
  selector: 
    app: mysql   # Pod that matches the target has this label
  template:      # Create a copy (instance) of Pod according to this grinding bar
    metadata:
      labels:
        app: mysql  # Label owned by the Pod copy, corresponding to the Selector of RC
    spec:
      containers:     # Definition part of Pod content
      - name: mysql   # Name of the container
        image: mysql  # Docker Image corresponding to container
        ports:
        - containerPort: 3306   # Port number of container application listening
        env:                    # Environment variables injected into the container
        - name: MYSQL_ROOT_PASSWORD   # This is the first time that I wrote MySQL root password incorrectly
          value: "root"

Issue RC file:

kubectl create -f mysql-rc.yaml

View created RC

kubectl get rc

View the creation of Pod

kubectl get pods

Failed to create, see more failure information

kubectl describe pod example

kubectl get events

View logs, error messages

kubectl logs -p <pod name>

error

➜  k8s kubectl logs -p mysql-lvq7v
error: database is uninitialized and password option is not specified
  You need to specify one of MYSQL_ROOT_PASSWORD, MYSQL_ALLOW_EMPTY_PASSWORD and MYSQL_RANDOM_ROOT_PASSWORD

This is the mysql password in the rc file. There's something wrong with it. Just change it

1. Create a service with the file name mysql-svc.yaml

apiVersion: v1
kind: Service         # Indicates Kubernetes Service 
metadata:
  name: mysql         # Globally unique name of the Service
spec:
  ports:
    - port: 3306      # The port number of the Service. It is written here as - port:3306 without spaces
  selector:           # The Pod corresponding to the Service has the label defined here
    app: mysql

Establish

kubectl create -f mysql-svc.yaml

View the service you just created

kubectl get svc

An error was encountered due to indentation

error: error validating "mysql-svc.yaml": error validating data: ValidationError(Service.spec.ports[0]): invalid type for io.k8s.api.core.v1.ServicePort: got "string", expected "map"; if you choose to ignore these errors, turn validation off with --validate=false

According to the unique name of the Service, the container can obtain the Cluster IP address and port corresponding to the Service from the environment variable, and then it can initiate a TCP/IP connection request.

This creates a mysql service.