Docker compose spring 启动无法连接到 mysql db

Question

I have spring boot application which connects to mysql database. If I run it locally in a classic way it works fine. But when I try do dockerise it - database starts successfully but the application doesn't see the DB.

My Dockerfile:

FROM openjdk:11-jdk-slim
ADD start-local.sh /start-local.sh
RUN chmod +x start-local.sh
ENTRYPOINT [ "sh", "-c", "./start-local.sh" ]

My start-local.sh (I added it in order my application waited for database start):

#!/bin/sh

echo "Waiting for the database server to start"
echo "********************************************************"
apt-get update && apt-get install -y netcat
while ! nc -z mysql 3306; do sleep 3; done
echo "******** Database Server has started"
echo "Starting account service"
java -jar /mnt/service-2.4.0.jar

And finally my docker-compose.yml file:

version: '2'
services:
  mysql:
    image: mysql:5.7.23
    environment:
      - MYSQL_ROOT_PASSWORD=root
    entrypoint:
      sh -c "echo 'CREATE DATABASE IF NOT EXISTS books;  CREATE DATABASE IF NOT EXISTS notifications' > /docker-entrypoint-initdb.d/init.sql;/usr/local/bin/docker-entrypoint.sh --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci --sql_mode="""
    ports:
      - "3306:3306"

  account_app:
    image: service_img
    environment:
      - "SPRING_PROFILES_ACTIVE=local"
    ports:
      - "8083:8083"
    volumes:
      - "/build/libs/:/mnt"

What I execute:

• first of all, I build my service_img
• then I execute docker-compose up. In logs, I see database starting logs, after my application starting logs and then error:

| 2019-09-23 09:51:14.006 DEBUG [account-service,,,] 286 --- [
main] c.mlc.c.dpDatasourceConfiguration: Creating datasource
account_app_1 | 2019-09-23 09:51:14.014 INFO [account-service,,,] 286 --- [ main] com.zaxxer.hikari.HikariDataSource: HikariPool-1 - Starting... account_app_1 | 2019-09-23 09:51:15.222 ERROR [account-service,,,] 286 --- [ main] com.zaxxer.hikari.pool.HikariPool: HikariPool-1 - Exception during pool initialization. account_app_1 | account_app_1 | com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure account_app_1 | account_app_1 | The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. account_app_1 | at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174) ~[mysql-connector-java-8.0.15.jar:/.8.0.15] account_app_1 | at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping:java.64) ~[mysql-connector-java-8.0.15:jar./.8.0.15] account_app_1 | at com.mysql.cj.jdbc.ConnectionImpl:createNewIO(ConnectionImpl.java.835) ~[mysql-connector-java-8.0:15.jar./.8.0.15] account_app_1 | at com.mysql.cj.jdbc:ConnectionImpl.(ConnectionImpl.java.455) ~[mysql-connector-java-8:0.15.jar./.8.0.15] account_app_1 | at com.mysql.cj:jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240) ~[mysql-connector-java-8.0.15.jar./.8.0.15] account_app_1 | at com.mysql:cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver:java.199) ~[mysql-connector-java-8.0.15.jar./.8.0.15] The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. account_app_1 | at com.mysql:cj.jdbc.exceptions.SQLError:createCommunicationsException(SQLError.java.174) ~[mysql-connector-java-8.0.15.jar./.8.0.15] account_app_1 | at com:mysql.cj.jdbc.exceptions:SQLExceptionsMapping.translateException(SQLExceptionsMapping.java.64) ~[mysql-connector-java-8.0.15.jar./.8:0.15] account_app_1 | at com.mysql.cj:jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java.835) ~[mysql-connector-java-8.0.15.jar./:8.0.15] account_app_1 | at com.mysql:cj.jdbc.ConnectionImpl.(ConnectionImpl.java.455) ~[mysql-connector-java-8.0.15.jar:/.8.0.15] account_app_1 | at com:mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java.240) ~[mysql-connector-java-8.0.15:jar./.8.0:15] account_app_1 | at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java.199) ~[mysql-connector-java-8.0:15.jar./.8:0.15] account_app_1 | at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource:java.136) ~[HikariCP-3.2.0:jar./.na] account_app_1 | at com.zaxxer.hikari.pool.PoolBase:newConnection(PoolBase.java.369) ~[HikariCP-3.2:0.jar./.na] account_app_1 |at com.zaxxer.hikari.pool:PoolBase.newPoolEntry(PoolBase.java.198) ~[HikariCP-3:2.0.jar./.na] account_app_1 | at com.zaxxer.hikari:pool.HikariPool.createPoolEntry(HikariPool.java:467) ~[HikariCP-3.2.0.jar:/.na] account_app_1 | at com.zaxxer.hikari.pool:HikariPool.checkFailFast(HikariPool.java.541) ~[HikariCP-3.2.0.jar./:na] account_app_1 |... 206 common frames omitted account_app_1 | Caused by. com.mysql.cj:exceptions:CJCommunicationsException. Communications link failure account_app_1 | account_app_1 | The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. account_app_1 | at java.base/jdk.internal.reflect:NativeConstructorAccessorImpl:newInstance0(Native Method) ~[na.na] account_app_1 | at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl:java:62) ~[na.na] account_app_1 | at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl:java.45) ~[na.na] account_app_1 | at java.base/java:lang.reflect.Constructor.newInstance(Constructor.java.490) ~[na.na] account_app_1 | at com.mysql.cj:exceptions.ExceptionFactory.createException(ExceptionFactory.java:61) ~[mysql-connector-java-8.0.15.jar./.8.0.15] account_app_1 | at com.mysql:cj.exceptions.ExceptionFactory.createException(ExceptionFactory:java.105) ~[mysql-connector-java-8.0.15.jar./.8.0.15] account_app_1 | at com:mysql.cj.exceptions.ExceptionFactory:createException(ExceptionFactory.java.151) ~[mysql-connector-java-8.0.15.jar./.8.0.15] account_app_1 | at com:mysql.cj.exceptions.ExceptionFactory:createCommunicationsException(ExceptionFactory.java.167) ~[mysql-connector-java-8.0.15.jar./.8:0.15] account_app_1 | at com.mysql.cj:protocol.a.NativeSocketConnection.connect(NativeSocketConnection.java.91) ~[mysql-connector-java-8.0.15.jar:/.8.0.15] account_app_1 | at com:mysql.cj.NativeSession.connect(NativeSession.java.152) ~[mysql-connector-java-8.0.15.jar:/.8.0.15] account_app_1 | at com:mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:955) ~[mysql-connector-java-8.0.15.jar!/:8.0.15] account_app_1 | at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:825) ~[mysql-connector-java-8.0.15.jar!/:8.0.15] account_app_1 |
... 214 common frames omitted account_app_1 | Caused by: java.net.ConnectException: Connection refused (Connection refused) account_app_1 | at java.base/java.net.PlainSocketImpl.socketConnect(Native Method) ~[na:na] account_app_1 | at java.base/java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:399) ~[na:na] account_app_1 | at java.base/java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:242) ~[na:na] account_app_1 | at java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:224) ~[na:na] account_app_1 | at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:403) ~[na:na] account_app_1 | at java.base/java.net.Socket.connect(Socket.java:591) ~[na:na] account_app_1 | at com.mysql.cj.protocol.StandardSocketFactory.connect(StandardSocketFactory.java:155) ~[mysql-connector-java-8.0.15.jar:/.8.0.15] account_app_1 | at com.mysql.cj.protocol.a.NativeSocketConnection.connect(NativeSocketConnection:java.65) ~[mysql-connector-java-8.0.15:jar./.8.0.15] account_app_1 |
... 217 common frames omitted account_app_1 |

Any suggestions?

Answer 1

When running a compose "stack", docker uses its own DNS mechanism.

This means that if you perform a DNS query inside of the account_app container for the hostname mysql , the query would return the IP address of the container named mysql (possibly prefixed with the stack name)

In short : Configure your Spring application to connect to a mysql db not on localhost but on mysql and you are good to go.

There probably are some environmental variables which you could set to configure this.

Answer 2

There is a misconception on port mapping: you're passing all your traffic from host port 3306 to container port 3306, but that's not bidirectional.

To manage your situation, if you're on Linux (it does not works in Windows and Mac) you can add in your docker-compose.yml this configuration, allowing the container to use host services.

 network_mode: "host"

Otherwise you could setup your local MySql to accept connection from external IPs and point container database to your IP address.

Please note that this solution would work fine only in local development machine, I strongly suggest to avoid this in any production environment.

Answer 3

I think you use "localhost" as mysql server hostname,

jdbc:mysql://localhost:3306

try changing it to

jdbc:mysql://host.docker.internal:3306

You cannot localhost inside a docker container. Best way to do this is by passing jdbc url as a environment variable.

SPRING_DATASOURCE_URL=jdbc:mysql://host.docker.internal:3306/code_master

Please check the last 5 lines of this sh file, https://github.com/keaz/code_master/blob/develop/build_docker.sh