A simple kubernetes Application deployment example

Description

We use an example to demonstrate the basic configuration of the Kubernetes deployment application.

This is a relatively simple example of a tomcat application plus a MySQL database

Running a simple webappp in Tomcat, this app accesses MySQL to get the data. and displayed on the page. For demonstration and simplification purposes, as long as the program is properly connected to the database, it automatically completes the preparation of the corresponding table creation and initialization data. So when we access the app through a browser, we'll show a table page with the data coming from the database.

Configuration

We create a webapp directory under the/root/k8s-yaml/directory and create four files in this directory:

.├── mysql-dm.yaml├── mysql-svc.yaml├── myweb-dm.yaml└── myweb-svc.yaml

The contents of these four documents are as follows:

Mysql-dm.yaml:

apiVersion: apps/v1beta1kind: Deploymentmetadata:  name: mysqlspec:  replicas: 1  selector:    matchLabels:      app: mysql  template:    metadata:      labels:        app: mysql    spec:      containers:      - name: mysql        image: mysql:5.7        ports:        - containerPort: 3306         env:        - name: MYSQL_ROOT_PASSWORD          value: "123456"

Mysql-svc.yaml:

apiVersion: v1kind: Servicemetadata:  name: mysqlspec:  ports:  - port: 3306  selector:    app: mysql``

Myweb-dm.yaml:

apiVersion: apps/v1beta1kind: Deploymentmetadata:  name: mywebspec:  replicas: 2  selector:    matchLabels:      app: myweb  template:    metadata:      labels:        app: myweb    spec:      containers:      - name: myweb        image: kubeguide/tomcat-app:v1        ports:        - containerPort: 8080        env:        - name: MYSQL_SERVICE_HOST          value: ‘mysql‘        - name: MYSQL_SERVICE_PORT          value: ‘3306

Myweb-svc.yaml:

apiVersion: v1kind: Servicemetadata:  name: mywebspec:  type: NodePort  ports:  - port: 8080    nodePort: 30001  selector:    app: myweb

We start with the following methods:

kubectl apply -f ./

Access:

/HTTP $node _ip:30001/demo

A simple kubernetes Application deployment example