There are more AWS SDK examples available in the [AWS Doc SDK Examples](https://github.com/awsdocs/aws-doc-sdk-examples) GitHub repo.

# Use `DescribeDBInstances` with an AWS SDK
<a name="aurora_example_aurora_DescribeDBInstances_section"></a>

The following code examples show how to use `DescribeDBInstances`.

Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code example: 
+  [Learn the basics](aurora_example_aurora_Scenario_GetStartedClusters_section.md) 

------
#### [ .NET ]

**SDK for .NET (v4)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv4/Aurora#code-examples). 

```
    /// <summary>
    /// Returns a list of DB instances.
    /// </summary>
    /// <param name="dbInstanceIdentifier">Optional name of a specific DB instance.</param>
    /// <returns>List of DB instances.</returns>
    public async Task<List<DBInstance>> DescribeDBInstancesPagedAsync(string? dbInstanceIdentifier = null)
    {
        var results = new List<DBInstance>();
        var instancesPaginator = _amazonRDS.Paginators.DescribeDBInstances(
            new DescribeDBInstancesRequest
            {
                DBInstanceIdentifier = dbInstanceIdentifier
            });
        // Get the entire list using the paginator.
        await foreach (var instances in instancesPaginator.DBInstances)
        {
            results.Add(instances);
        }
        return results;
    }
```
+  For API details, see [DescribeDBInstances](https://docs.aws.amazon.com/goto/DotNetSDKV4/rds-2014-10-31/DescribeDBInstances) in *AWS SDK for .NET API Reference*. 

------
#### [ C\$1\$1 ]

**SDK for C\$1\$1**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/aurora#code-examples). 

```
        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 a DB instance description.
/*!
 \sa describeDBCluster()
 \param dbInstanceIdentifier: A DB instance identifier.
 \param instanceResult: The 'DBInstance' object containing the description.
 \param client: 'RDSClient' instance.
 \return bool: Successful completion.
 */
bool AwsDoc::Aurora::describeDBInstance(const Aws::String &dbInstanceIdentifier,
                                        Aws::RDS::Model::DBInstance &instanceResult,
                                        const Aws::RDS::RDSClient &client) {
    Aws::RDS::Model::DescribeDBInstancesRequest request;
    request.SetDBInstanceIdentifier(dbInstanceIdentifier);

    Aws::RDS::Model::DescribeDBInstancesOutcome outcome =
            client.DescribeDBInstances(request);

    bool result = true;
    if (outcome.IsSuccess()) {
        instanceResult = outcome.GetResult().GetDBInstances()[0];
    }
    else if (outcome.GetError().GetErrorType() !=
             Aws::RDS::RDSErrors::D_B_INSTANCE_NOT_FOUND_FAULT) {
        result = false;
        std::cerr << "Error with Aurora::DescribeDBInstances. "
                  << outcome.GetError().GetMessage()
                  << std::endl;
    }
        // This example does not log an error if the DB instance does not exist.
        // Instead, instanceResult is set to empty.
    else {
        instanceResult = Aws::RDS::Model::DBInstance();
    }

    return result;
}
```
+  For API details, see [DescribeDBInstances](https://docs.aws.amazon.com/goto/SdkForCpp/rds-2014-10-31/DescribeDBInstances) in *AWS SDK for C\$1\$1 API Reference*. 

------
#### [ Go ]

**SDK for Go V2**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/aurora#code-examples). 

```
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
}



// GetInstance gets data about a DB instance.
func (clusters *DbClusters) GetInstance(ctx context.Context, instanceName string) (
	*types.DBInstance, error) {
	output, err := clusters.AuroraClient.DescribeDBInstances(ctx,
		&rds.DescribeDBInstancesInput{
			DBInstanceIdentifier: aws.String(instanceName),
		})
	if err != nil {
		var notFoundError *types.DBInstanceNotFoundFault
		if errors.As(err, &notFoundError) {
			log.Printf("DB instance %v does not exist.\n", instanceName)
			err = nil
		} else {
			log.Printf("Couldn't get instance %v: %v\n", instanceName, err)
		}
		return nil, err
	} else {
		return &output.DBInstances[0], nil
	}
}
```
+  For API details, see [DescribeDBInstances](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/rds#Client.DescribeDBInstances) in *AWS SDK for Go API Reference*. 

------
#### [ Java ]

**SDK for Java 2.x**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/rds#code-examples). 

```
    // Waits until the database instance is available.
    public static void waitForInstanceReady(RdsClient rdsClient, String dbClusterIdentifier) {
        boolean instanceReady = false;
        String instanceReadyStr;
        System.out.println("Waiting for instance to become available.");
        try {
            DescribeDbClustersRequest instanceRequest = DescribeDbClustersRequest.builder()
                    .dbClusterIdentifier(dbClusterIdentifier)
                    .build();

            while (!instanceReady) {
                DescribeDbClustersResponse response = rdsClient.describeDBClusters(instanceRequest);
                List<DBCluster> clusterList = response.dbClusters();
                for (DBCluster cluster : clusterList) {
                    instanceReadyStr = cluster.status();
                    if (instanceReadyStr.contains("available")) {
                        instanceReady = true;
                    } else {
                        System.out.print(".");
                        Thread.sleep(sleepTime * 1000);
                    }
                }
            }
            System.out.println("Database cluster is available!");

        } catch (RdsException | InterruptedException e) {
            System.err.println(e.getMessage());
            System.exit(1);
        }
    }
```
+  For API details, see [DescribeDBInstances](https://docs.aws.amazon.com/goto/SdkForJavaV2/rds-2014-10-31/DescribeDBInstances) in *AWS SDK for Java 2.x API Reference*. 

------
#### [ Kotlin ]

**SDK for Kotlin**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/rds#code-examples). 

```
suspend fun waitDBAuroraInstanceReady(dbInstanceIdentifierVal: String?) {
    var instanceReady = false
    var instanceReadyStr: String
    println("Waiting for instance to become available.")
    val instanceRequest =
        DescribeDbInstancesRequest {
            dbInstanceIdentifier = dbInstanceIdentifierVal
        }

    var endpoint = ""
    RdsClient.fromEnvironment { region = "us-west-2" }.use { rdsClient ->
        while (!instanceReady) {
            val response = rdsClient.describeDbInstances(instanceRequest)
            response.dbInstances?.forEach { instance ->
                instanceReadyStr = instance.dbInstanceStatus.toString()
                if (instanceReadyStr.contains("available")) {
                    endpoint = instance.endpoint?.address.toString()
                    instanceReady = true
                } else {
                    print(".")
                    delay(sleepTime * 1000)
                }
            }
        }
    }
    println("Database instance is available! The connection endpoint is $endpoint")
}
```
+  For API details, see [DescribeDBInstances](https://sdk.amazonaws.com/kotlin/api/latest/index.html) in *AWS SDK for Kotlin API reference*. 

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/aurora#code-examples). 

```
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_db_instance(self, instance_id):
        """
        Gets data about a DB instance.

        :param instance_id: The ID of the DB instance to retrieve.
        :return: The retrieved DB instance.
        """
        try:
            response = self.rds_client.describe_db_instances(
                DBInstanceIdentifier=instance_id
            )
            db_inst = response["DBInstances"][0]
        except ClientError as err:
            if err.response["Error"]["Code"] == "DBInstanceNotFound":
                logger.info("Instance %s does not exist.", instance_id)
            else:
                logger.error(
                    "Couldn't get DB instance %s. Here's why: %s: %s",
                    instance_id,
                    err.response["Error"]["Code"],
                    err.response["Error"]["Message"],
                )
                raise
        else:
            return db_inst
```
+  For API details, see [DescribeDBInstances](https://docs.aws.amazon.com/goto/boto3/rds-2014-10-31/DescribeDBInstances) in *AWS SDK for Python (Boto3) API Reference*. 

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/aurora#code-examples). 

```
    pub async fn clean_up(self) -> Result<(), Vec<ScenarioError>> {
        let mut clean_up_errors: Vec<ScenarioError> = vec![];

        // Delete the instance. rds.DeleteDbInstance.
        let delete_db_instance = self
            .rds
            .delete_db_instance(
                self.db_instance_identifier
                    .as_deref()
                    .expect("instance identifier"),
            )
            .await;
        if let Err(err) = delete_db_instance {
            let identifier = self
                .db_instance_identifier
                .as_deref()
                .unwrap_or("Missing Instance Identifier");
            let message = format!("failed to delete db instance {identifier}");
            clean_up_errors.push(ScenarioError::new(message, &err));
        } else {
            // Wait for the instance to delete
            let waiter = Waiter::default();
            while waiter.sleep().await.is_ok() {
                let describe_db_instances = self.rds.describe_db_instances().await;
                if let Err(err) = describe_db_instances {
                    clean_up_errors.push(ScenarioError::new(
                        "Failed to check instance state during deletion",
                        &err,
                    ));
                    break;
                }
                let db_instances = describe_db_instances
                    .unwrap()
                    .db_instances()
                    .iter()
                    .filter(|instance| instance.db_cluster_identifier == self.db_cluster_identifier)
                    .cloned()
                    .collect::<Vec<DbInstance>>();

                if db_instances.is_empty() {
                    trace!("Delete Instance waited and no instances were found");
                    break;
                }
                match db_instances.first().unwrap().db_instance_status() {
                    Some("Deleting") => continue,
                    Some(status) => {
                        info!("Attempting to delete but instances is in {status}");
                        continue;
                    }
                    None => {
                        warn!("No status for DB instance");
                        break;
                    }
                }
            }
        }

        // Delete the DB cluster. rds.DeleteDbCluster.
        let delete_db_cluster = self
            .rds
            .delete_db_cluster(
                self.db_cluster_identifier
                    .as_deref()
                    .expect("cluster identifier"),
            )
            .await;

        if let Err(err) = delete_db_cluster {
            let identifier = self
                .db_cluster_identifier
                .as_deref()
                .unwrap_or("Missing DB Cluster Identifier");
            let message = format!("failed to delete db cluster {identifier}");
            clean_up_errors.push(ScenarioError::new(message, &err));
        } else {
            // Wait for the instance and cluster to fully delete. rds.DescribeDbInstances and rds.DescribeDbClusters until both are not found.
            let waiter = Waiter::default();
            while waiter.sleep().await.is_ok() {
                let describe_db_clusters = self
                    .rds
                    .describe_db_clusters(
                        self.db_cluster_identifier
                            .as_deref()
                            .expect("cluster identifier"),
                    )
                    .await;
                if let Err(err) = describe_db_clusters {
                    clean_up_errors.push(ScenarioError::new(
                        "Failed to check cluster state during deletion",
                        &err,
                    ));
                    break;
                }
                let describe_db_clusters = describe_db_clusters.unwrap();
                let db_clusters = describe_db_clusters.db_clusters();
                if db_clusters.is_empty() {
                    trace!("Delete cluster waited and no clusters were found");
                    break;
                }
                match db_clusters.first().unwrap().status() {
                    Some("Deleting") => continue,
                    Some(status) => {
                        info!("Attempting to delete but clusters is in {status}");
                        continue;
                    }
                    None => {
                        warn!("No status for DB cluster");
                        break;
                    }
                }
            }
        }

        // Delete the DB cluster parameter group. rds.DeleteDbClusterParameterGroup.
        let delete_db_cluster_parameter_group = self
            .rds
            .delete_db_cluster_parameter_group(
                self.db_cluster_parameter_group
                    .map(|g| {
                        g.db_cluster_parameter_group_name
                            .unwrap_or_else(|| DB_CLUSTER_PARAMETER_GROUP_NAME.to_string())
                    })
                    .as_deref()
                    .expect("cluster parameter group name"),
            )
            .await;
        if let Err(error) = delete_db_cluster_parameter_group {
            clean_up_errors.push(ScenarioError::new(
                "Failed to delete the db cluster parameter group",
                &error,
            ))
        }

        if clean_up_errors.is_empty() {
            Ok(())
        } else {
            Err(clean_up_errors)
        }
    }

    pub async fn describe_db_instances(
        &self,
    ) -> Result<DescribeDbInstancesOutput, SdkError<DescribeDBInstancesError>> {
        self.inner.describe_db_instances().send().await
    }

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

    mock_rds
        .expect_delete_db_instance()
        .with(eq("MockInstance"))
        .return_once(|_| Ok(DeleteDbInstanceOutput::builder().build()));

    mock_rds
        .expect_describe_db_instances()
        .with()
        .times(1)
        .returning(|| {
            Ok(DescribeDbInstancesOutput::builder()
                .db_instances(
                    DbInstance::builder()
                        .db_cluster_identifier("MockCluster")
                        .db_instance_status("Deleting")
                        .build(),
                )
                .build())
        })
        .with()
        .times(1)
        .returning(|| Ok(DescribeDbInstancesOutput::builder().build()));

    mock_rds
        .expect_delete_db_cluster()
        .with(eq("MockCluster"))
        .return_once(|_| Ok(DeleteDbClusterOutput::builder().build()));

    mock_rds
        .expect_describe_db_clusters()
        .with(eq("MockCluster"))
        .times(1)
        .returning(|id| {
            Ok(DescribeDbClustersOutput::builder()
                .db_clusters(
                    DbCluster::builder()
                        .db_cluster_identifier(id)
                        .status("Deleting")
                        .build(),
                )
                .build())
        })
        .with(eq("MockCluster"))
        .times(1)
        .returning(|_| Ok(DescribeDbClustersOutput::builder().build()));

    mock_rds
        .expect_delete_db_cluster_parameter_group()
        .with(eq("MockParamGroup"))
        .return_once(|_| Ok(DeleteDbClusterParameterGroupOutput::builder().build()));

    let mut scenario = AuroraScenario::new(mock_rds);
    scenario.db_cluster_identifier = Some(String::from("MockCluster"));
    scenario.db_instance_identifier = Some(String::from("MockInstance"));
    scenario.db_cluster_parameter_group = Some(
        DbClusterParameterGroup::builder()
            .db_cluster_parameter_group_name("MockParamGroup")
            .build(),
    );

    tokio::time::pause();
    let assertions = tokio::spawn(async move {
        let clean_up = scenario.clean_up().await;
        assert!(clean_up.is_ok());
    });

    tokio::time::advance(Duration::from_secs(1)).await; // Wait for first Describe Instances
    tokio::time::advance(Duration::from_secs(1)).await; // Wait for second Describe Instances
    tokio::time::advance(Duration::from_secs(1)).await; // Wait for first Describe Cluster
    tokio::time::advance(Duration::from_secs(1)).await; // Wait for second Describe Cluster
    tokio::time::resume();
    let _ = assertions.await;
}

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

    mock_rds
        .expect_delete_db_instance()
        .with(eq("MockInstance"))
        .return_once(|_| Ok(DeleteDbInstanceOutput::builder().build()));

    mock_rds
        .expect_describe_db_instances()
        .with()
        .times(1)
        .returning(|| {
            Ok(DescribeDbInstancesOutput::builder()
                .db_instances(
                    DbInstance::builder()
                        .db_cluster_identifier("MockCluster")
                        .db_instance_status("Deleting")
                        .build(),
                )
                .build())
        })
        .with()
        .times(1)
        .returning(|| {
            Err(SdkError::service_error(
                DescribeDBInstancesError::unhandled(Box::new(Error::new(
                    ErrorKind::Other,
                    "describe db instances error",
                ))),
                Response::new(StatusCode::try_from(400).unwrap(), SdkBody::empty()),
            ))
        });

    mock_rds
        .expect_delete_db_cluster()
        .with(eq("MockCluster"))
        .return_once(|_| Ok(DeleteDbClusterOutput::builder().build()));

    mock_rds
        .expect_describe_db_clusters()
        .with(eq("MockCluster"))
        .times(1)
        .returning(|id| {
            Ok(DescribeDbClustersOutput::builder()
                .db_clusters(
                    DbCluster::builder()
                        .db_cluster_identifier(id)
                        .status("Deleting")
                        .build(),
                )
                .build())
        })
        .with(eq("MockCluster"))
        .times(1)
        .returning(|_| {
            Err(SdkError::service_error(
                DescribeDBClustersError::unhandled(Box::new(Error::new(
                    ErrorKind::Other,
                    "describe db clusters error",
                ))),
                Response::new(StatusCode::try_from(400).unwrap(), SdkBody::empty()),
            ))
        });

    mock_rds
        .expect_delete_db_cluster_parameter_group()
        .with(eq("MockParamGroup"))
        .return_once(|_| Ok(DeleteDbClusterParameterGroupOutput::builder().build()));

    let mut scenario = AuroraScenario::new(mock_rds);
    scenario.db_cluster_identifier = Some(String::from("MockCluster"));
    scenario.db_instance_identifier = Some(String::from("MockInstance"));
    scenario.db_cluster_parameter_group = Some(
        DbClusterParameterGroup::builder()
            .db_cluster_parameter_group_name("MockParamGroup")
            .build(),
    );

    tokio::time::pause();
    let assertions = tokio::spawn(async move {
        let clean_up = scenario.clean_up().await;
        assert!(clean_up.is_err());
        let errs = clean_up.unwrap_err();
        assert_eq!(errs.len(), 2);
        assert_matches!(errs.first(), Some(ScenarioError {message, context: _}) if message == "Failed to check instance state during deletion");
        assert_matches!(errs.get(1), Some(ScenarioError {message, context: _}) if message == "Failed to check cluster state during deletion");
    });

    tokio::time::advance(Duration::from_secs(1)).await; // Wait for first Describe Instances
    tokio::time::advance(Duration::from_secs(1)).await; // Wait for second Describe Instances
    tokio::time::advance(Duration::from_secs(1)).await; // Wait for first Describe Cluster
    tokio::time::advance(Duration::from_secs(1)).await; // Wait for second Describe Cluster
    tokio::time::resume();
    let _ = assertions.await;
}
```
+  For API details, see [DescribeDBInstances](https://docs.rs/aws-sdk-rds/latest/aws_sdk_rds/client/struct.Client.html#method.describe_db_instances) in *AWS SDK for Rust API reference*. 

------