[FIXED] Not able to connect with MySQL server to Spring Application in Docker?

Issue

i'm new to Docker, as a part of dockerization of spring mvc application , i'm not able to connect my application to MySQL server

Dockerfile :this is Spring mvc application so need to copy my war to

 tomcat container
    FROM tomcat:8.0.20-jre8
    COPY /target/CTH.war /usr/local/tomcat/webapps/

docker-compose.yml

  version: '3'
services:
  mysql-standalone:
    image: 'mysql:5.7'
    command: mysqld --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci
    volumes:
      - ./docker/provision/mysql/init:/docker-entrypoint-initdb.d
    environment:
      - MYSQL_ROOT_PASSWORD= root
      - MYSQL_USER= root
      - MYSQL_PASSWORD= root
      - MYSQL_DATABASE= CTH
      - MYSQL_DATABASE= CTH_CHAT
    ports:
      - "3307:3306"
  cth-docker-container:
    image: cth-docker-container
    ports:
      - "8082:8082"
    environment:
      CTH_DATASOURCE_DATABASE: CTH
      CTH_DATASOURCE_SERVERNAME: mysql-standalone
      CTH_DATASOURCE_USERNAME: root
      CTH_DATASOURCE_PASSWORD: root
      CTH_DATASOURCE_PORT: 3307

      CTH_CHAT_DATASOURCE_DATABASE: CTH_CHAT
      CTH_CHAT_DATASOURCE_SERVERNAME: mysql-standalone
      CTH_CHAT_DATASOURCE_USERNAME: root
      CTH_CHAT_DATASOURCE_PASSWORD: root
      CTH_CHAT_DATASOURCE_PORT: 3307

    build:
      context: "./"
      dockerfile: "Dockerfile"
    depends_on:
      - mysql-standalone

application.properties :this is spring mvc application and application uses MySQL db with two databases

1st db
dbuser.local=${CTH_DATASOURCE_USERNAME:root}
dbpassword.local=${CTH_DATASOURCE_PASSWORD:root}
dbdatabaseName.local=${CTH_DATASOURCE_DATABASE:CTH}
dbserverName.local=${CTH_DATASOURCE_SERVERNAME:localhost}
dbportNumber.local=${CTH_DATASOURCE_PORT:3306} 

2nd db
dbuser.cth.chat.local=${CTH_CHAT_DATASOURCE_USERNAME:root}
dbpassword.cth.chat.local=${CTH_CHAT_DATASOURCE_PASSWORD:root}
dbdatabaseName.cth.chat.local=${CTH_CHAT_DATASOURCE_USERNAME:CTH_CHAT}
dbserverName.cth.chat.local=${CTH_CHAT_DATASOURCE_SERVERNAME:localhost}
dbportNumber.cth.chat.local=${CTH_CHAT_DATASOURCE_PORT:3306}

i read articles from which i created dockerfile and docker-compose file https://medium.com/@asce4s/dockerize-spring-mvc-application-a9ffbd11eadb https://github.com/abagayev/docker-bootstrap-collection/tree/master/mysql-few-databases/docker/provision/mysql/init

but i'm getting following erros when i execute docker-compose -f docker-compose.yml up

Caused by: com.mysql.cj.core.exceptions.CJCommunicationsException: Communications link failure cth-docker-container_1 | cth-docker-container_1 | The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. cth-docker-container_1 | at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) cth-docker-container_1 | at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) cth-docker-container_1 | at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) cth-docker-container_1 | at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490) cth-docker-container_1 | at com.mysql.cj.core.exceptions.ExceptionFactory.createException(ExceptionFactory.java:54) cth-docker-container_1 | at com.mysql.cj.core.exceptions.ExceptionFactory.createException(ExceptionFactory.java:93) cth-docker-container_1 | at com.mysql.cj.core.exceptions.ExceptionFactory.createException(ExceptionFactory.java:133) cth-docker-container_1 | at com.mysql.cj.core.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:149) cth-docker-container_1 | at com.mysql.cj.mysqla.io.MysqlaSocketConnection.connect(MysqlaSocketConnection.java:83) cth-docker-container_1 | at com.mysql.cj.mysqla.MysqlaSession.connect(MysqlaSession.java:122) cth-docker-container_1 | at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:1754) cth-docker-container_1 | at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:1624) cth-docker-container_1 | ... 125 common frames omitted cth-docker-container_1 | Caused by: java.net.UnknownHostException: mysql-standalone cth-docker-container_1 | at java.base/java.net.InetAddress$CachedAddresses.get(InetAddress.java:797) cth-docker-container_1 | at java.base/java.net.InetAddress.getAllByName0(InetAddress.java:1505) cth-docker-container_1 | at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1364) cth-docker-container_1 | at java.base/java.net.InetAddress.getAllByName(InetAddress.java:1298) cth-docker-container_1 | at com.mysql.cj.core.io.StandardSocketFactory.connect(StandardSocketFactory.java:179) cth-docker-container_1 | at com.mysql.cj.mysqla.io.MysqlaSocketConnection.connect(MysqlaSocketConnection.java:57) cth-docker-container_1 | ... 128 common frames omitted

i'm stuck and not getting if i have set wrong environment or my way is not correct your any suggestion i'll definitely help me thanks!

Solution

After reading lots of articles, I got success to up my application with MySQL db in a docker container and access in Mysql workbench.

here is my docker-compose file

version: '3'

services:
  app:
    container_name: cth-app
    build:
      context: .
      dockerfile: Dockerfile
    ports:
      - '8080:8080'
    environment:
      ##db1
      CTH_DATASOURCE_DATABASE: CTH
      CTH_DATASOURCE_HOST: mysqldb
      CTH_DATASOURCE_USERNAME: cth
      CTH_DATASOURCE_PASSWORD: root
      CTH_DATASOURCE_PORT: 3306

      ##db2
      CTH_CHAT_DATASOURCE_DATABASENAME: CTH_CHAT
      CTH_CHAT_DATASOURCE_HOST: mysqldb
      CTH_CHAT_DATASOURCE_USERNAME: cth
      CTH_CHAT_DATASOURCE_PASSWORD: root
      CTH_CHAT_DATASOURCE_PORT: 3306
    depends_on:
      - mysqldb

  mysqldb:
    image: mysql/mysql-server:5.7
    container_name: mysqldb
    command: mysqld --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci
    ##here i am able to access dump file which I'll create two databases 
      with user created for me.
    volumes:
      - ./docker/provision/mysql/init:/docker-entrypoint-initdb.d
    ports:
      - '3308:3306'
    environment:
        MYSQL_ROOT_PASSWORD: root
        MYSQL_USER: cth
        MYSQL_PASSWORD: root

you need to create a dump file refer the article [ https://github.com/abagayev/docker-bootstrap-collection/tree/master/mysql-few-databases]

when you'll docker-compose up -d --build

your application is up running on port 8080, with MySQL DB running inside a host machine

Thanks!

Answered By - Shivam Patil