Introduce CassandraDriverOptionsConfigurer and allow specifying a configuration file [DATACASS-798]

[spring-projects-issues]

Abhijit Sarkar opened DATACASS-798 and commented

It seems almost every Cassandra @Configuration class declares its own private static class CassandraDriverOptions; AbstractSessionConfiguration does, CassandraAutoConfiguration does too. Apart from duplication of code, hiding the driver options from the users means configurations that are not exposed through CassandraProperties can't be easily done.

It would make a lot of sense to make the CassandraDriverOptions public, create a CassandraDriverOptionsConfigurer type, and call user provided implementations of the latter while building the options.

Currently I do something like this, which is a lot of unnecessary code:

override fun cassandraSession(): CqlSessionFactoryBean {
    return super.cassandraSession().apply {
        setSessionBuilderConfigurer {
            if (cassandraProperties.username?.isNotEmpty() == true) {
                it.withAuthProvider(
                    ProgrammaticPlainTextAuthProvider(
                        cassandraProperties.username, cassandraProperties.password
                    )
                )
            }
            it.withConfigLoader(cassandraDriverConfigLoader())
        }
    }
}

@Bean
fun cassandraDriverConfigLoader(): DriverConfigLoader {
    val builder = DefaultProgrammaticDriverConfigLoaderBuilder({
        ConfigFactory.invalidateCaches()
        ConfigFactory.defaultOverrides()
            .withFallback(driverConfig())
            .withFallback(ConfigFactory.defaultReference())
            .resolve()
    }, DefaultDriverConfigLoader.DEFAULT_ROOT_PATH)

    return builder.build()
}
@ConditionalOnMissingBean
@Bean
fun driverConfig(): Config {
    val options = CassandraDriverOptions()
    sessionName
        ?.takeIf { StringUtils.hasText(it) }
        ?.also { options.add(DefaultDriverOption.SESSION_NAME, it) }
    compressionType
        ?.also { options.add(DefaultDriverOption.PROTOCOL_COMPRESSION, it) }
    myCassandraProperties.ssl?.keyStore
        ?.also { options.add(DefaultDriverOption.SSL_KEYSTORE_PATH, it) }
    myCassandraProperties.ssl?.keyStorePassword
        ?.also { options.add(DefaultDriverOption.SSL_KEYSTORE_PASSWORD, it) }
    myCassandraProperties.ssl?.trustStore
        ?.also { options.add(DefaultDriverOption.SSL_TRUSTSTORE_PATH, it) }
    myCassandraProperties.ssl?.trustStorePassword
        ?.also { options.add(DefaultDriverOption.SSL_TRUSTSTORE_PASSWORD, it) }
    myCassandraProperties.protocolVersion
        .takeIf { it > 0 }
        ?.also { pv ->
            options.add(
                DefaultDriverOption.PROTOCOL_VERSION,
                DefaultProtocolVersion.values().first { it.code == pv })
        }
    // Related to spring.data.cassandra.local-datacenter
    myCassandraProperties.policies?.loadBalancing
        ?.also { options.add(DefaultDriverOption.LOAD_BALANCING_POLICY_CLASS, it) }
    myCassandraProperties.policies?.retry
        ?.also { options.add(DefaultDriverOption.RETRY_POLICY_CLASS, it) }

    return options.build()
}

---

Affects: 3.0.3 (Neumann SR3)

Backported to: 3.1.2 (2020.0.2)

[spring-projects-issues]

Mark Paluch commented

CassandraDriverOptions is an internal utility that is used as holder for driver options. Instead of exposing the internal utility, it would make sense to introduce a customizer for ProgrammaticDriverConfigLoaderBuilder. (See DriverConfigLoaderBuilderCustomizer for reference).

By customizing the actual builder you can use the public driver API to apply your customizations.

[spring-projects-issues]

Abhijit Sarkar commented

Mark Paluch I looked at DriverConfigLoaderBuilderCustomizer, and wasn't sure how to use it. Is what I'm asking for already available here CassandraAutoConfiguration.java#L113? But CassandraAutoConfiguration is not invoked if AbstractCassandraConfiguration is subclassed by user

[spring-projects-issues]

Mark Paluch commented

DriverConfigLoaderBuilderCustomizer is part of Spring Boot. We would copy the concept into Spring Data Cassandra so you can apply customization in the same way by just using Spring Data Cassandra, without Spring Boot

[spring-projects-issues]

Abhijit Sarkar commented

I see, makes sense. Although the number of people that actually use Spring data without Boot is probably only a handful