Allow users to specify a MongoDB database name

[silaev]

Related issue #2876

When one uses Testcontainer’s reuse feature, a framework and a database per a test as a way to separate(isolate) data, then specifying a database might be helpful.
For instance, in the Spring Data MongoDB a database name is bound to the MongoTemplate/
ReactiveMongoTemplate and thus it’s a tedious process to change a database name for above-mentioned testing scenario.

Given that, this PR adds a withDatabaseName method for the MongoDBContainer. If the withDatabaseName mothod is not called, then a database name will default to "test" as now. an overloaded getReplicaSetUrl(final String databaseName). The prior getReplicaSetUrl() remains as earlier.

[rnorth]

Should we perhaps have a test for this, to guard against regressions?

[silaev]

Should we perhaps have a test for this, to guard against regressions?

Specifying a database name appeals more to frameworks. While working with a Java MongoDB driver directly, we usually call MongoClient#getDatabase() and that's when we specify a database name. Setting a database name in a URL does not lead to a database creation.

However in frameworks, for example in Spring Boot+Spring Data MongoDB, a database name got set to MongoTemplate during auto-configuration from a URL. Then, we don't have to call any getDatabase method at all, a database is created during a first writing call via MongoTemplate/ReactiveMongoTemplate.

Given that I've added a light-weight @DataMongoTest called MongoDBContainerDatabaseNameTest and some additional dependencies in test scope to the build.gradle file of the mongodb module.

[bsideup]

@silaev please don't. There is no point in bringing full Spring Boot-based test just to get that getReplicaSetUrl(String) returns correct result. It will only add way more load on CI for nothing.

[silaev]

@silaev please don't. There is no point in bringing full Spring Boot-based test just to get that getReplicaSetUrl(String) returns correct result. It will only add way more load on CI for nothing.

Reverted the Spring Boot-based test, added a simple unit test shouldTestDatabaseName.
As I mentioned before, there is no way to assert that this database is created in MongoDB physically (setting a database name in a URL does not lead to a database creation.).

[silaev]

@rnorth @bsideup Could we merge this PR?

[rnorth]

👍 This looks fine to me.