Spring-boot: HikariCP logs 'testdb starting' when no testdb has been configured

[NicoTexas]

With just a simple jdbc configuration of a datasource

spring.datasource.url = jdbc:postgresql://localhost:5433/mydb
spring.datasource.username=postgres
spring.datasource.password=postgres

When starting a Spring Boot 2.0.0 M7 application, we get a confusing log statement

2018-01-21 21:11:49.996  INFO 15380 --- [           main] com.zaxxer.hikari.HikariDataSource       : testdb - Starting...
2018-01-21 21:11:50.040  INFO 15380 --- [           main] com.zaxxer.hikari.pool.PoolBase          : testdb - Driver does not support get/set network timeout for connections. (Method org.postgresql.jdbc.PgConnection.getNetworkTimeout() is not yet implemented.)
2018-01-21 21:11:50.052  INFO 15380 --- [           main] com.zaxxer.hikari.HikariDataSource       : testdb - Start completed.
2018-01-21 21:11:50.056  INFO 15380 --- [           main] o.f.c.internal.database.DatabaseFactory  : Database: jdbc:postgresql://localhost:5433/mydb(PostgreSQL 9.5)

It appears it comes from auto-configuration https://github.com/spring-projects/spring-boot/blob/v2.0.0.M7/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jdbc/DataSourceProperties.java
where the default value for spring.datasource.name is 'testdb'

See https://github.com/openbouquet/HikariCP/blob/master/src/main/java/com/zaxxer/hikari/HikariDataSource.java

Looks like Spring Boot is setting the spring.datasource.name as the pool name in HikariConfig somehow.

org.springframework.boot.autoconfigure.jdbc.DataSourceConfiguration

        @ConditionalOnClass(HikariDataSource.class)
    @ConditionalOnProperty(name = "spring.datasource.type", havingValue = "com.zaxxer.hikari.HikariDataSource", matchIfMissing = true)
    static class Hikari extends DataSourceConfiguration {

        @Bean
        @ConfigurationProperties(prefix = "spring.datasource.hikari")
        public HikariDataSource dataSource(DataSourceProperties properties) {
            HikariDataSource dataSource = createDataSource(properties,
                    HikariDataSource.class);
            if (properties.getName() != null) {
                dataSource.setPoolName(properties.getName());
            }
            return dataSource;
        }
    }

[snicoll]

See #9547

Sorry, I overlooked completely the fact that name is set by default with such specific name. I think one way to fix this problem would be to make it null by default (with a testdb init for the embedded case).

[snicoll]

I've pushed 9107f06 but I am not sure I like it yet. EmbeddedDataSourceConfiguration should reuse what EmbeddedDatabaseConnection does. In particular, DataSourceProperties#determineUrl could be simply reused rather than passing the same value to the builder. I had a quick look to that (overriding the DataSourceFactory to use) and it looks doable.

I could use a second look on the initial proposal.

[philwebb]

@snicoll I've pushed the naming logic into DataSourceProperties and exposed it by making deduceDatabaseName() public. The EmbeddedDatabaseConnection now requires a databaseName parameter.

That feels fairly sensible. I think the default name is a concern of auto-configuration, so it's best to keep it in that module. As a bonus we also can remove the generate unique name stuff in EmbeddedDataSourceConfiguration because deduceDatabaseName already does that.

Feel free to re-open the issue if the change doesn't feel right.