How to set up Docker containers for Java Spring Boot and MySql

Question

I cannot get my Docker container running a Java Spring Boot Api layer to communicate with my Docker container running a MySql database.

1) I created the MySql image as follows:

docker run -d 
--name aname-mysql 
-e MYSQL_ROOT_PASSWORD=root 
-e MYSQL_DATABASE=db 
-e MYSQL_USER=root 
-e MYSQL_PASSWORD=root 
mysql:5.7

2) I built the Docker image for the Java Spring Boot app as follows:

./gradlew build docker -x test

3) I created the Docker container for the Java Spring Boot app as follows:

docker run -d 
-p 8080:8080 --name app-api 
--link aname-mysql:mysql 
-e DATABASE_HOST=aname-mysql 
-e DATABASE_PORT:3306 
-e DATABASE_NAME=db 
-e DATABASE_USER=root 
-e DATABASE_PASSWORD=root 
com.app/my.api

4) My Dockerfile looks like this

FROM openjdk:8-jdk-alpine
VOLUME /tmp
ARG JAR_FILE
ADD ${JAR_FILE} app.jar
ENTRYPOINT ["java", "-Djava.security.egd=file:/dev/./urandom", "-Dspring.profiles.active=container", "-jar","/app.jar"]

5) My application-container.yml file looks like this

server:
  port: 8080

spring:
  datasource:
    url: jdbc:mysql://${DATABASE_HOST}:${DATABASE_PORT}/${DATABASE_NAME}?autoReconnect=true&useSSL=false
    username: ${DATABASE_USER}
    password: ${DATABASE_PASSWORD}
  jpa:
    database-platform: org.hibernate.dialect.MySQL5InnoDBDialect
    properties:
      hibernate:
        dialect: org.hibernate.dialect.MySQL5InnoDBDialect
    hibernate:
      ddl-auto: validate
      show_sql: true

After running these commands and then entering

http://localhost:8080/api/users

I get an error stating that the site refuses to connect and only the default browser error page is shown. Please tell me what I'm doing wrong. Thanks.

Answer 1

create a docker-compose.yaml and put the following

version: '2'
services:
  database:
    container_name:db
    restart: always
    image: mysql
    ports:
      - 3306:3306
    environment:
      MYSQL_ROOT_PASSWORD: example
  java:
    image: <YOUR JAVA IMAGE>
    links:
     - "database"

start services:

docker-compose up

try to connect to it through localhost:3306 from java or get the ip of db container:

docker inspect db

look for the public ip then connect to it

Answer 2

将两个应用程序都放入docker组成，并通过其docker名称相互引用。

Answer 3

I just noticed a typo. Instead of DATABASE_PORT=3306, I used a colon. With this correction, the Java Spring Boot container is now linked to and working properly with the MySql container.