Springboot Microservice running on docker not able to connect to mysql

Question

I am using spring-boot to run my microservice on docker which is using MySQL, but my app is not able to make the connection with MySQL

The exception is :

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
app_1  |    at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174)
app_1  |    at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64)
app_1  |    at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:836)
app_1  |    at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:456)
app_1  |    at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:246)
app_1  |    at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:197)
app_1  |    at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:121)
app_1  |    at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:358)
app_1  |    at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:206)
app_1  |    at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:477)
app_1  |    at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:560)
app_1  |    ... 69 more
app_1  | Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure
app_1  | 
app_1  | The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
app_1  |    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
app_1  |    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
app_1  |    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
app_1  |    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
app_1  |    at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:61)
app_1  |    at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:105)
app_1  |    at com.mysql.cj.exceptions.ExceptionFactory.createException(ExceptionFactory.java:151)
app_1  |    at com.mysql.cj.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:167)
app_1  |    at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:91)
app_1  |    at com.mysql.cj.NativeSession.connect(NativeSession.java:144)
app_1  |    at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:956)
app_1  |    at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:826)
app_1  |    ... 77 more
app_1  | Caused by: java.net.ConnectException: Connection refused (Connection refused)
app_1  |    at java.net.PlainSocketImpl.socketConnect(Native Method)
app_1  |    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
app_1  |    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
app_1  |    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
app_1  |    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
app_1  |    at java.net.Socket.connect(Socket.java:589)
app_1  |    at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:155)
app_1  |    at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java:65)
app_1  |    ... 80 more

the docker-compose file is :

version: '3'

services:
  db:
    image: mysql:5.7
    restart: always
    environment:
      - MYSQL_DATABASE=inward
      # So you don't have to use root, but you can if you like
      - MYSQL_USER=root
      # You can use whatever password you like
      - MYSQL_PASSWORD=unroot
      # Password for root access
      - MYSQL_ROOT_PASSWORD=unroot
    ports:
      # <Port exposed> : < MySQL Port running inside container>
      - 3307:3306

  app:
    build:
      context: ./
      dockerfile: Dockerfile
    environment:
      SPRING_DATASOURCE_URL: jdbc:mysql://db:3306/inward?allowPublicKeyRetrieval=true&useSSL=false
    depends_on:
      - db
    working_dir: /app
    command: [sh, -c, 'mkdir -p ~/logs/; cd /src ; mvn clean spring-boot:run -Dspring.profiles.active=dev -DLOG_DIR=/root/logs/ -DLOG_FILE=hubstamper.log']
    ports:
      - "8080:8080"
    volumes:
      - "${HOME}/.m2:/root/.m2"

Dockerfiule

FROM maven:3.5-jdk-8-alpine
COPY . /app

and application.properties file is :

jdbcUrl=jdbc:mysql://db:3306/inward?allowPublicKeyRetrieval=true&useSSL=false
dataSource.user=root
dataSource.password=unroot
dataSource.cachePrepStmts=true
dataSource.prepStmtCacheSize=250
dataSource.prepStmtCacheSqlLimit=2048
driverClassName=com.mysql.jdbc.Driver
dataSource.driverClassName=com.mysql.jdbc.Driver

I have tried the solution mentioned in the link : Communications link failure , Spring Boot + MySql +Docker + Hibernate

any help will be higly appriciable.

Answer 1

I could solve this problem with docker-compose file

services:
  db:
    image: mysql:5.7
    restart: always
    environment:
      - MYSQL_DATABASE=inward
      # So you don't have to use root, but you can if you like
      - MYSQL_USER=root
      # You can use whatever password you like
      - MYSQL_PASSWORD=unroot
      # Password for root access
      - MYSQL_ROOT_PASSWORD=unroot
    ports:
      # <Port exposed> : < MySQL Port running inside container>
      - 3307:3306

  app:
    build:
      context: ./
      dockerfile: Dockerfile
    depends_on:
      - db
    working_dir: /app
    command: [sh, -c, 'mkdir -p ~/logs/; cd /src ; mvn clean spring-boot:run -Dspring.profiles.active=local -DLOG_DIR=/root/logs/ -DLOG_FILE=hubstamper.log']
    ports:
      - 8080:8080
    volumes:
      - "${HOME}/.m2:/root/.m2"

and apllication-local.properties file

jdbcUrl=jdbc:mysql://db:3306/inward?allowPublicKeyRetrieval=true&useSSL=false
dataSource.user=root
dataSource.password=unroot
dataSource.cachePrepStmts=true
dataSource.prepStmtCacheSize=250
dataSource.prepStmtCacheSqlLimit=2048
driverClassName=com.mysql.jdbc.Driver
dataSource.driverClassName=com.mysql.jdbc.Driver

and docker file

FROM maven:3.5-jdk-8-alpine
COPY . /app

And please make sure every time you change anything in code, remove the old docker image, and create a new one(This is also I was missing in my approach).