Docker container connection to database (image with a Java Spring boot app)

Question

I have a simple SpringBoot Rest application that has a way of writing down a simple model into a database and collecting it again. I made a Docker image out of the application but when I run it I get these errors:

2018-07-25 18:17:13.531  WARN 1 --- [           main] unknown.jul.logger                       : ConnectException occurred while connecting to localhost:5432

java.net.ConnectException: Connection refused (Connection refused)
        at java.net.PlainSocketImpl.socketConnect(Native Method) ~[na:1.8.0_171]
        at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350) ~[na:1.8.0_171]
        at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206) ~[na:1.8.0_171]
        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188) ~[na:1.8.0_171]
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:1.8.0_171]
        at java.net.Socket.connect(Socket.java:589) ~[na:1.8.0_171]
        at org.postgresql.core.PGStream.<init>(PGStream.java:69) ~[postgresql-42.2.2.jar!/:42.2.2]
        at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:156) ~[postgresql-42.2.2.jar!/:42.2.2]
        at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49) [postgresql-42.2.2.jar!/:42.2.2]
        at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:195) [postgresql-42.2.2.jar!/:42.2.2]
        at org.postgresql.Driver.makeConnection(Driver.java:452) [postgresql-42.2.2.jar!/:42.2.2]
        at org.postgresql.Driver.connect(Driver.java:254) [postgresql-42.2.2.jar!/:42.2.2]
        at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:117) [HikariCP-2.7.9.jar!/:na]
        at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:123) [HikariCP-2.7.9.jar!/:na]
        at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:365) [HikariCP-2.7.9.jar!/:na]
        at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:194) [HikariCP-2.7.9.jar!/:na]
        at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:460) [HikariCP-2.7.9.jar!/:na]
        at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:534) [HikariCP-2.7.9.jar!/:na]
        at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115) [HikariCP-2.7.9.jar!/:na]
        at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) [HikariCP-2.7.9.jar!/:na]
        at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:151) [spring-jdbc-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:115) [spring-jdbc-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:78) [spring-jdbc-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:319) [spring-jdbc-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:356) [spring-jdbc-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.boot.autoconfigure.orm.jpa.DatabaseLookup.getDatabase(DatabaseLookup.java:72) [spring-boot-autoconfigure-2.0.3.RELEASE.jar!/:2.0.3.RELEASE]
        at org.springframework.boot.autoconfigure.orm.jpa.JpaProperties.determineDatabase(JpaProperties.java:166) [spring-boot-autoconfigure-2.0.3.RELEASE.jar!/:2.0.3.RELEASE]
        at org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.jpaVendorAdapter(JpaBaseConfiguration.java:111) [spring-boot-autoconfigure-2.0.3.RELEASE.jar!/:2.0.3.RELEASE]
        at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration$$EnhancerBySpringCGLIB$$208c14a2.CGLIB$jpaVendorAdapter$4(<generated>) [spring-boot-autoconfigure-2.0.3.RELEASE.jar!/:2.0.3.RELEASE]
        at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration$$EnhancerBySpringCGLIB$$208c14a2$$FastClassBySpringCGLIB$$189e846c.invoke(<generated>) [spring-boot-autoconfigure-2.0.3.RELEASE.jar!/:2.0.3.RELEASE]
        at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) [spring-core-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:361) [spring-context-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration$$EnhancerBySpringCGLIB$$208c14a2.jpaVendorAdapter(<generated>) [spring-boot-autoconfigure-2.0.3.RELEASE.jar!/:2.0.3.RELEASE]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_171]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_171]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_171]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_171]
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:582) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1256) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1105) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:503) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:251) ~[spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138) ~[spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1065) ~[spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:818) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:724) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:474) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1256) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1105) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:503) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:251) ~[spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138) ~[spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1065) ~[spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:818) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:724) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:474) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1256) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1105) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:503) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:317) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:315) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) [spring-beans-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1089) ~[spring-context-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:859) ~[spring-context-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:550) ~[spring-context-5.0.7.RELEASE.jar!/:5.0.7.RELEASE]
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.3.RELEASE.jar!/:2.0.3.RELEASE]
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) ~[spring-boot-2.0.3.RELEASE.jar!/:2.0.3.RELEASE]
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395) ~[spring-boot-2.0.3.RELEASE.jar!/:2.0.3.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) ~[spring-boot-2.0.3.RELEASE.jar!/:2.0.3.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255) ~[spring-boot-2.0.3.RELEASE.jar!/:2.0.3.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243) ~[spring-boot-2.0.3.RELEASE.jar!/:2.0.3.RELEASE]
        at nl.timonschultz.heroes.heroesapp.HeroesApplication.main(HeroesApplication.java:10) ~[classes!/:1.0-SNAPSHOT]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_171]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_171]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_171]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_171]
        at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48) ~[heroes-app.jar:1.0-SNAPSHOT]
        at org.springframework.boot.loader.Launcher.launch(Launcher.java:87) ~[heroes-app.jar:1.0-SNAPSHOT]
        at org.springframework.boot.loader.Launcher.launch(Launcher.java:50) ~[heroes-app.jar:1.0-SNAPSHOT]
        at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:51) ~[heroes-app.jar:1.0-SNAPSHOT]

2018-07-25 18:17:13.538 ERROR 1 --- [           main] org.postgresql.Driver                    : Connection error:

org.postgresql.util.PSQLException: Connection to localhost:5432 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.

I think this relates to the database (error refers to the port the DB runs on). It can't connect to a dockerized Postgres DB. I ran a test from another image to ping my local machine and that works.

docker container run --rm -it alpine sh
apk update && apk add iputils
ping 192.168.1.3

These are some relevant file's: Dockerfile:

FROM openjdk:8-jdk-alpine
VOLUME /tmp
COPY ./heroes-app-boot/target/heroes-app-boot-1.0-SNAPSHOT.jar ./heroes-app.jar
ENTRYPOINT ["java","-Djava.security.egd=file:/dev/./urandom","-jar","/heroes-app.jar"]

Application.properties:

spring.datasource.url=jdbc:postgresql://localhost:5432/postgres
spring.datasource.username=postgres
spring.datasource.password=mysecretpassword
spring.jpa.properties.hibernate.jdbc.lob.non_contextual_creation=true

### JPA configuration ###
spring.jpa.generate-ddl=true
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=create-drop

Do I need to configere the connection further or, better yet, can I add an 'embeded DB' into my Image?

Answer 1

If you have dockerized Postgres DB you should use the name of the containers in your connection url. Given the container name is postgre-docker, your connection url should be

spring.datasource.url=jdbc:postgresql://postgre-docker/postgres

Also, make sure you link your spring boot app to your postgres containers via docker run --link postgre-docker <rest of the run command> or in your docker-compose file via -link option. Alternatively, you could create a network and add both application to the network via --network=yournetwork option. To create a network,

docker network create yournetwork