Use DescribeDBEngineVersions with an AWS SDK

    /// <summary>
    /// Get a list of DB engine versions for a particular DB engine.
    /// </summary>
    /// <param name="engine">The name of the engine.</param>
    /// <param name="parameterGroupFamily">Optional parameter group family name.</param>
    /// <returns>A list of DBEngineVersions.</returns>
    public async Task<List<DBEngineVersion>> DescribeDBEngineVersionsForEngineAsync(string engine,
        string? parameterGroupFamily = null)
    {
        var response = await _amazonRDS.DescribeDBEngineVersionsAsync(
            new DescribeDBEngineVersionsRequest()
            {
                Engine = engine,
                DBParameterGroupFamily = parameterGroupFamily
            });
        return response.DBEngineVersions;
    }

        Aws::Client::ClientConfiguration clientConfig;
        // Optional: Set to the AWS Region (overrides config file).
        // clientConfig.region = "us-east-1";

    Aws::RDS::RDSClient client(clientConfig);


//! Routine which gets available DB engine versions for an engine name and
//! an optional parameter group family.
/*!
 \sa getDBEngineVersions()
 \param engineName: A DB engine name.
 \param parameterGroupFamily: A parameter group family name, ignored if empty.
 \param engineVersionsResult: Vector of 'DBEngineVersion' objects returned by the routine.
 \param client: 'RDSClient' instance.
 \return bool: Successful completion.
 */
bool AwsDoc::Aurora::getDBEngineVersions(const Aws::String &engineName,
                                         const Aws::String &parameterGroupFamily,
                                         Aws::Vector<Aws::RDS::Model::DBEngineVersion> &engineVersionsResult,
                                         const Aws::RDS::RDSClient &client) {
    Aws::RDS::Model::DescribeDBEngineVersionsRequest request;
    request.SetEngine(engineName);
    if (!parameterGroupFamily.empty()) {
        request.SetDBParameterGroupFamily(parameterGroupFamily);
    }

    engineVersionsResult.clear();
    Aws::String marker; // The marker is used for pagination.
    do {
        if (!marker.empty()) {
            request.SetMarker(marker);
        }

        Aws::RDS::Model::DescribeDBEngineVersionsOutcome outcome =
                client.DescribeDBEngineVersions(request);

        if (outcome.IsSuccess()) {
            const Aws::Vector<Aws::RDS::Model::DBEngineVersion> &engineVersions =
                    outcome.GetResult().GetDBEngineVersions();

            engineVersionsResult.insert(engineVersionsResult.end(),
                                        engineVersions.begin(), engineVersions.end());
            marker  = outcome.GetResult().GetMarker();
        }
        else {
            std::cerr << "Error with Aurora::DescribeDBEngineVersionsRequest. "
                      << outcome.GetError().GetMessage()
                      << std::endl;
        }
    } while (!marker.empty());

    return true;
}

import (
	"context"
	"errors"
	"log"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/service/rds"
	"github.com/aws/aws-sdk-go-v2/service/rds/types"
)

type DbClusters struct {
	AuroraClient *rds.Client
}



// GetEngineVersions gets database engine versions that are available for the specified engine
// and parameter group family.
func (clusters *DbClusters) GetEngineVersions(ctx context.Context, engine string, parameterGroupFamily string) (
	[]types.DBEngineVersion, error) {
	output, err := clusters.AuroraClient.DescribeDBEngineVersions(ctx,
		&rds.DescribeDBEngineVersionsInput{
			Engine:                 aws.String(engine),
			DBParameterGroupFamily: aws.String(parameterGroupFamily),
		})
	if err != nil {
		log.Printf("Couldn't get engine versions for %v: %v\n", engine, err)
		return nil, err
	} else {
		return output.DBEngineVersions, nil
	}
}

    public static void describeDBEngines(RdsClient rdsClient) {
        try {
            DescribeDbEngineVersionsRequest engineVersionsRequest = DescribeDbEngineVersionsRequest.builder()
                    .engine("aurora-mysql")
                    .defaultOnly(true)
                    .maxRecords(20)
                    .build();

            DescribeDbEngineVersionsResponse response = rdsClient.describeDBEngineVersions(engineVersionsRequest);
            List<DBEngineVersion> engines = response.dbEngineVersions();

            // Get all DBEngineVersion objects.
            for (DBEngineVersion engineOb : engines) {
                System.out.println("The name of the DB parameter group family for the database engine is "
                        + engineOb.dbParameterGroupFamily());
                System.out.println("The name of the database engine " + engineOb.engine());
                System.out.println("The version number of the database engine " + engineOb.engineVersion());
            }

        } catch (RdsException e) {
            System.out.println(e.getLocalizedMessage());
            System.exit(1);
        }
    }

// Get a list of allowed engine versions.
suspend fun getAllowedClusterEngines(dbParameterGroupFamilyVal: String?) {
    val versionsRequest =
        DescribeDbEngineVersionsRequest {
            dbParameterGroupFamily = dbParameterGroupFamilyVal
            engine = "aurora-mysql"
        }

    RdsClient { region = "us-west-2" }.use { rdsClient ->
        val response = rdsClient.describeDbEngineVersions(versionsRequest)
        response.dbEngineVersions?.forEach { dbEngine ->
            println("The engine version is ${dbEngine.engineVersion}")
            println("The engine description is ${dbEngine.dbEngineDescription}")
        }
    }
}

class AuroraWrapper:
    """Encapsulates Aurora DB cluster actions."""

    def __init__(self, rds_client):
        """
        :param rds_client: A Boto3 Amazon Relational Database Service (Amazon RDS) client.
        """
        self.rds_client = rds_client

    @classmethod
    def from_client(cls):
        """
        Instantiates this class from a Boto3 client.
        """
        rds_client = boto3.client("rds")
        return cls(rds_client)


    def get_engine_versions(self, engine, parameter_group_family=None):
        """
        Gets database engine versions that are available for the specified engine
        and parameter group family.

        :param engine: The database engine to look up.
        :param parameter_group_family: When specified, restricts the returned list of
                                       engine versions to those that are compatible with
                                       this parameter group family.
        :return: The list of database engine versions.
        """
        try:
            kwargs = {"Engine": engine}
            if parameter_group_family is not None:
                kwargs["DBParameterGroupFamily"] = parameter_group_family
            response = self.rds_client.describe_db_engine_versions(**kwargs)
            versions = response["DBEngineVersions"]
        except ClientError as err:
            logger.error(
                "Couldn't get engine versions for %s. Here's why: %s: %s",
                engine,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise
        else:
            return versions

    // Get available engine families for Aurora MySql. rds.DescribeDbEngineVersions(Engine='aurora-mysql') and build a set of the 'DBParameterGroupFamily' field values. I get {aurora-mysql8.0, aurora-mysql5.7}.
    pub async fn get_engines(&self) -> Result<HashMap<String, Vec<String>>, ScenarioError> {
        let describe_db_engine_versions = self.rds.describe_db_engine_versions(DB_ENGINE).await;
        trace!(versions=?describe_db_engine_versions, "full list of versions");

        if let Err(err) = describe_db_engine_versions {
            return Err(ScenarioError::new(
                "Failed to retrieve DB Engine Versions",
                &err,
            ));
        };

        let version_count = describe_db_engine_versions
            .as_ref()
            .map(|o| o.db_engine_versions().len())
            .unwrap_or_default();
        info!(version_count, "got list of versions");

        // Create a map of engine families to their available versions.
        let mut versions = HashMap::<String, Vec<String>>::new();
        describe_db_engine_versions
            .unwrap()
            .db_engine_versions()
            .iter()
            .filter_map(
                |v| match (&v.db_parameter_group_family, &v.engine_version) {
                    (Some(family), Some(version)) => Some((family.clone(), version.clone())),
                    _ => None,
                },
            )
            .for_each(|(family, version)| versions.entry(family).or_default().push(version));

        Ok(versions)
    }

    pub async fn describe_db_engine_versions(
        &self,
        engine: &str,
    ) -> Result<DescribeDbEngineVersionsOutput, SdkError<DescribeDBEngineVersionsError>> {
        self.inner
            .describe_db_engine_versions()
            .engine(engine)
            .send()
            .await
    }

#[tokio::test]
async fn test_scenario_get_engines() {
    let mut mock_rds = MockRdsImpl::default();

    mock_rds
        .expect_describe_db_engine_versions()
        .with(eq("aurora-mysql"))
        .return_once(|_| {
            Ok(DescribeDbEngineVersionsOutput::builder()
                .db_engine_versions(
                    DbEngineVersion::builder()
                        .db_parameter_group_family("f1")
                        .engine_version("f1a")
                        .build(),
                )
                .db_engine_versions(
                    DbEngineVersion::builder()
                        .db_parameter_group_family("f1")
                        .engine_version("f1b")
                        .build(),
                )
                .db_engine_versions(
                    DbEngineVersion::builder()
                        .db_parameter_group_family("f2")
                        .engine_version("f2a")
                        .build(),
                )
                .db_engine_versions(DbEngineVersion::builder().build())
                .build())
        });

    let scenario = AuroraScenario::new(mock_rds);

    let versions_map = scenario.get_engines().await;

    assert_eq!(
        versions_map,
        Ok(HashMap::from([
            ("f1".into(), vec!["f1a".into(), "f1b".into()]),
            ("f2".into(), vec!["f2a".into()])
        ]))
    );
}

#[tokio::test]
async fn test_scenario_get_engines_failed() {
    let mut mock_rds = MockRdsImpl::default();

    mock_rds
        .expect_describe_db_engine_versions()
        .with(eq("aurora-mysql"))
        .return_once(|_| {
            Err(SdkError::service_error(
                DescribeDBEngineVersionsError::unhandled(Box::new(Error::new(
                    ErrorKind::Other,
                    "describe_db_engine_versions error",
                ))),
                Response::new(StatusCode::try_from(400).unwrap(), SdkBody::empty()),
            ))
        });

    let scenario = AuroraScenario::new(mock_rds);

    let versions_map = scenario.get_engines().await;
    assert_matches!(
        versions_map,
        Err(ScenarioError { message, context: _ }) if message == "Failed to retrieve DB Engine Versions"
    );
}