Esempi per Amazon Redshift con SDK per Python (Boto3)

import boto3


def hello_redshift(redshift_client):
    """
    Use the AWS SDK for Python (Boto3) to create an Amazon Redshift client and list
    the clusters in your account. This list might be empty if you haven't created
    any clusters.
    This example uses the default settings specified in your shared credentials
    and config files.

    :param redshift_client: A Boto3 Redshift Client object.
    """
    print("Hello, Redshift! Let's list your clusters:")
    paginator = redshift_client.get_paginator("describe_clusters")
    clusters = []
    for page in paginator.paginate():
        clusters.extend(page["Clusters"])

    print(f"{len(clusters)} cluster(s) were found.")

    for cluster in clusters:
        print(f"  {cluster['ClusterIdentifier']}")


if __name__ == "__main__":
    hello_redshift(boto3.client("redshift"))

class RedshiftScenario:
    """Runs an interactive scenario that shows how to get started with Redshift."""

    def __init__(self, redshift_wrapper, redshift_data_wrapper):
        self.redshift_wrapper = redshift_wrapper
        self.redshift_data_wrapper = redshift_data_wrapper

    def redhift_scenario(self, json_file_path):
        database_name = "dev"

        print(DASHES)
        print("Welcome to the Amazon Redshift SDK Getting Started example.")
        print(
            """
      This Python program demonstrates how to interact with Amazon Redshift 
      using the AWS SDK for Python (Boto3).
      
      Amazon Redshift is a fully managed, petabyte-scale data warehouse 
      service hosted in the cloud.
      
      The program's primary functionalities include cluster creation, 
      verification of cluster readiness, listing databases, table creation, 
      populating data within the table, and executing SQL statements.
      
      It also demonstrates querying data from the Movies table.
      
      Upon completion, all AWS resources are cleaned up.
    """
        )
        if not os.path.isfile(json_file_path):
            logging.error(f"The file {json_file_path} does not exist.")
            return

        print("Let's get started...")
        user_name = q.ask("Please enter your user name (default is awsuser):")
        user_name = user_name if user_name else "awsuser"

        print(DASHES)
        user_password = q.ask(
            "Please enter your user password (default is AwsUser1000):"
        )
        user_password = user_password if user_password else "AwsUser1000"

        print(DASHES)
        print(
            """A Redshift cluster refers to the collection of computing resources and storage that work 
            together to process and analyze large volumes of data."""
        )
        cluster_id = q.ask(
            "Enter a cluster identifier value (default is redshift-cluster-movies): "
        )
        cluster_id = cluster_id if cluster_id else "redshift-cluster-movies"

        self.redshift_wrapper.create_cluster(
            cluster_id, "ra3.4xlarge", user_name, user_password, True, 2
        )

        print(DASHES)
        print(f"Wait until {cluster_id} is available. This may take a few minutes...")
        q.ask("Press Enter to continue...")

        self.wait_cluster_available(cluster_id)

        print(DASHES)

        print(
            f"""
       When you created {cluster_id}, the dev database is created by default and used in this scenario.

       To create a custom database, you need to have a CREATEDB privilege.
       For more information, see the documentation here: 
       https://docs.aws.amazon.com/redshift/latest/dg/r_CREATE_DATABASE.html.
      """
        )
        q.ask("Press Enter to continue...")
        print(DASHES)

        print(DASHES)
        print(f"List databases in {cluster_id}")
        q.ask("Press Enter to continue...")
        databases = self.redshift_data_wrapper.list_databases(
            cluster_id, database_name, user_name
        )
        print(f"The cluster contains {len(databases)} database(s).")
        for database in databases:
            print(f"    Database: {database}")
        print(DASHES)

        print(DASHES)
        print("Now you will create a table named Movies.")
        q.ask("Press Enter to continue...")

        self.create_table(cluster_id, database_name, user_name)

        print(DASHES)

        print("Populate the Movies table using the Movies.json file.")
        print(
            "Specify the number of records you would like to add to the Movies Table."
        )
        print("Please enter a value between 50 and 200.")

        while True:
            try:
                num_records = int(q.ask("Enter a value: ", q.is_int))
                if 50 <= num_records <= 200:
                    break
                else:
                    print("Invalid input. Please enter a value between 50 and 200.")
            except ValueError:
                print("Invalid input. Please enter a value between 50 and 200.")

        self.populate_table(
            cluster_id, database_name, user_name, json_file_path, num_records
        )

        print(DASHES)
        print("Query the Movies table by year. Enter a value between 2012-2014.")

        while True:
            movie_year = int(q.ask("Enter a year: ", q.is_int))
            if 2012 <= movie_year <= 2014:
                break
            else:
                print("Invalid input. Please enter a valid year between 2012 and 2014.")

        # Function to query database
        sql_id = self.query_movies_by_year(
            database_name, user_name, movie_year, cluster_id
        )

        print(f"The identifier of the statement is {sql_id}")

        print("Checking statement status...")
        self.wait_statement_finished(sql_id)
        result = self.redshift_data_wrapper.get_statement_result(sql_id)

        self.display_movies(result)

        print(DASHES)

        print(DASHES)
        print("Now you will modify the Redshift cluster.")
        q.ask("Press Enter to continue...")

        preferred_maintenance_window = "wed:07:30-wed:08:00"
        self.redshift_wrapper.modify_cluster(cluster_id, preferred_maintenance_window)

        print(DASHES)

        print(DASHES)
        delete = q.ask("Do you want to delete the cluster? (y/n) ", q.is_yesno)

        if delete:
            print(f"You selected to delete {cluster_id}")
            q.ask("Press Enter to continue...")
            self.redshift_wrapper.delete_cluster(cluster_id)
        else:
            print(f"Cluster {cluster_id}cluster_id was not deleted")

        print(DASHES)
        print("This concludes the Amazon Redshift SDK Getting Started scenario.")
        print(DASHES)

    def create_table(self, cluster_id, database, username):
        self.redshift_data_wrapper.execute_statement(
            cluster_identifier=cluster_id,
            database_name=database,
            user_name=username,
            sql="CREATE TABLE Movies (statement_id INT PRIMARY KEY, title VARCHAR(100), year INT)",
        )

        print("Table created: Movies")


    def populate_table(self, cluster_id, database, username, file_name, number):
        with open(file_name) as f:
            data = json.load(f)

        i = 0
        for record in data:
            if i == number:
                break

            statement_id = i
            title = record["title"]
            year = record["year"]
            i = i + 1
            parameters = [
                {"name": "statement_id", "value": str(statement_id)},
                {"name": "title", "value": title},
                {"name": "year", "value": str(year)},
            ]

            self.redshift_data_wrapper.execute_statement(
                cluster_identifier=cluster_id,
                database_name=database,
                user_name=username,
                sql="INSERT INTO Movies VALUES(:statement_id, :title, :year)",
                parameter_list=parameters,
            )

        print(f"{i} records inserted into Movies table")

    def wait_cluster_available(self, cluster_id):
        """
        Waits for a cluster to be available.

        :param cluster_id: The cluster identifier.

        Note: The cluster_available waiter can also be used.
        It is not used in this case to allow an elapsed time message.
        """
        cluster_ready = False
        start_time = time.time()

        while not cluster_ready:
            time.sleep(30)
            cluster = self.redshift_wrapper.describe_clusters(cluster_id)
            status = cluster[0]["ClusterStatus"]
            if status == "available":
                cluster_ready = True
            elif status != "creating":
                raise Exception(
                    f"Cluster {cluster_id} creation failed with status {status}."
                )

            elapsed_seconds = int(round(time.time() - start_time))
            minutes = int(elapsed_seconds // 60)
            seconds = int(elapsed_seconds % 60)

            print(f"Elapsed Time: {minutes}:{seconds:02d} - status {status}...")

            if minutes > 30:
                raise Exception(
                    f"Cluster {cluster_id} is not available after 30 minutes."
                )

    def query_movies_by_year(self, database, username, year, cluster_id):
        sql = "SELECT * FROM Movies WHERE year = :year"

        params = [{"name": "year", "value": str(year)}]

        response = self.redshift_data_wrapper.execute_statement(
            cluster_identifier=cluster_id,
            database_name=database,
            user_name=username,
            sql=sql,
            parameter_list=params,
        )

        return response["Id"]

    @staticmethod
    def display_movies(response):
        metadata = response["ColumnMetadata"]
        records = response["Records"]

        title_column_index = None
        for i in range(len(metadata)):
            if metadata[i]["name"] == "title":
                title_column_index = i
                break

        if title_column_index is None:
            print("No title column found.")
            return

        print(f"Found {len(records)} movie(s).")
        for record in records:
            print(f"   {record[title_column_index]['stringValue']}")

    def wait_statement_finished(self, sql_id):
        while True:
            time.sleep(1)
            response = self.redshift_data_wrapper.describe_statement(sql_id)
            status = response["Status"]
            print(f"Statement status is {status}.")

            if status == "FAILED":
                print(f"The query failed because {response['Error']}. Ending program")
                raise Exception("The Query Failed. Ending program")
            elif status == "FINISHED":
                break

Funzione principale che descrive l’implementazione dello scenario.

def main():
    redshift_client = boto3.client("redshift")
    redshift_data_client = boto3.client("redshift-data")
    redshift_wrapper = RedshiftWrapper(redshift_client)
    redshift_data_wrapper = RedshiftDataWrapper(redshift_data_client)
    redshift_scenario = RedshiftScenario(redshift_wrapper, redshift_data_wrapper)
    redshift_scenario.redhift_scenario(
        f"{os.path.dirname(__file__)}/../../../resources/sample_files/movies.json"
    )

Le funzioni wrapper utilizzate nello scenario.

    def create_cluster(
        self,
        cluster_identifier,
        node_type,
        master_username,
        master_user_password,
        publicly_accessible,
        number_of_nodes,
    ):
        """
        Creates a cluster.

        :param cluster_identifier: The name of the cluster.
        :param node_type: The type of node in the cluster.
        :param master_username: The master username.
        :param master_user_password: The master user password.
        :param publicly_accessible: Whether the cluster is publicly accessible.
        :param number_of_nodes: The number of nodes in the cluster.
        :return: The cluster.
        """

        try:
            cluster = self.client.create_cluster(
                ClusterIdentifier=cluster_identifier,
                NodeType=node_type,
                MasterUsername=master_username,
                MasterUserPassword=master_user_password,
                PubliclyAccessible=publicly_accessible,
                NumberOfNodes=number_of_nodes,
            )
            return cluster
        except ClientError as err:
            logging.error(
                "Couldn't create a cluster. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise


    def describe_clusters(self, cluster_identifier):
        """
        Describes a cluster.

        :param cluster_identifier: The cluster identifier.
        :return: A list of clusters.
        """
        try:
            kwargs = {}
            if cluster_identifier:
                kwargs["ClusterIdentifier"] = cluster_identifier

            paginator = self.client.get_paginator("describe_clusters")
            clusters = []
            for page in paginator.paginate(**kwargs):
                clusters.extend(page["Clusters"])

            return clusters

        except ClientError as err:
            logging.error(
                "Couldn't describe a cluster. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise


    def execute_statement(
        self, cluster_identifier, database_name, user_name, sql, parameter_list=None
    ):
        """
        Executes a SQL statement.

        :param cluster_identifier: The cluster identifier.
        :param database_name: The database name.
        :param user_name: The user's name.
        :param sql: The SQL statement.
        :param parameter_list: The optional SQL statement parameters.
        :return: The SQL statement result.
        """

        try:
            kwargs = {
                "ClusterIdentifier": cluster_identifier,
                "Database": database_name,
                "DbUser": user_name,
                "Sql": sql,
            }
            if parameter_list:
                kwargs["Parameters"] = parameter_list
            response = self.client.execute_statement(**kwargs)
            return response
        except ClientError as err:
            logging.error(
                "Couldn't execute statement. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise


    def describe_statement(self, statement_id):
        """
        Describes a SQL statement.

        :param statement_id: The SQL statement identifier.
        :return: The SQL statement result.
        """
        try:
            response = self.client.describe_statement(Id=statement_id)
            return response
        except ClientError as err:
            logging.error(
                "Couldn't describe statement. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise


    def get_statement_result(self, statement_id):
        """
        Gets the result of a SQL statement.

        :param statement_id: The SQL statement identifier.
        :return: The SQL statement result.
        """
        try:
            result = {
                "Records": [],
            }
            paginator = self.client.get_paginator("get_statement_result")
            for page in paginator.paginate(Id=statement_id):
                if "ColumnMetadata" not in result:
                    result["ColumnMetadata"] = page["ColumnMetadata"]
                result["Records"].extend(page["Records"])
            return result
        except ClientError as err:
            logging.error(
                "Couldn't get statement result. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise


    def modify_cluster(self, cluster_identifier, preferred_maintenance_window):
        """
        Modifies a cluster.

        :param cluster_identifier: The cluster identifier.
        :param preferred_maintenance_window: The preferred maintenance window.
        """
        try:
            self.client.modify_cluster(
                ClusterIdentifier=cluster_identifier,
                PreferredMaintenanceWindow=preferred_maintenance_window,
            )
        except ClientError as err:
            logging.error(
                "Couldn't modify a cluster. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise


    def list_databases(self, cluster_identifier, database_name, database_user):
        """
        Lists databases in a cluster.

        :param cluster_identifier: The cluster identifier.
        :param database_name: The database name.
        :param database_user: The database user.
        :return: The list of databases.
        """
        try:
            paginator = self.client.get_paginator("list_databases")
            databases = []
            for page in paginator.paginate(
                ClusterIdentifier=cluster_identifier,
                Database=database_name,
                DbUser=database_user,
            ):
                databases.extend(page["Databases"])

            return databases
        except ClientError as err:
            logging.error(
                "Couldn't list databases. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise


    def delete_cluster(self, cluster_identifier):
        """
        Deletes a cluster.

        :param cluster_identifier: The cluster identifier.
        """
        try:
            self.client.delete_cluster(
                ClusterIdentifier=cluster_identifier, SkipFinalClusterSnapshot=True
            )
        except ClientError as err:
            logging.error(
                "Couldn't delete a cluster. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise

class RedshiftWrapper:
    """
    Encapsulates Amazon Redshift cluster operations.
    """

    def __init__(self, redshift_client):
        """
        :param redshift_client: A Boto3 Redshift client.
        """
        self.client = redshift_client


    def create_cluster(
        self,
        cluster_identifier,
        node_type,
        master_username,
        master_user_password,
        publicly_accessible,
        number_of_nodes,
    ):
        """
        Creates a cluster.

        :param cluster_identifier: The name of the cluster.
        :param node_type: The type of node in the cluster.
        :param master_username: The master username.
        :param master_user_password: The master user password.
        :param publicly_accessible: Whether the cluster is publicly accessible.
        :param number_of_nodes: The number of nodes in the cluster.
        :return: The cluster.
        """

        try:
            cluster = self.client.create_cluster(
                ClusterIdentifier=cluster_identifier,
                NodeType=node_type,
                MasterUsername=master_username,
                MasterUserPassword=master_user_password,
                PubliclyAccessible=publicly_accessible,
                NumberOfNodes=number_of_nodes,
            )
            return cluster
        except ClientError as err:
            logging.error(
                "Couldn't create a cluster. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise

Il codice seguente crea un’istanza dell’oggetto RedshiftWrapper.

    client = boto3.client("redshift")
    redhift_wrapper = RedshiftWrapper(client)

class RedshiftWrapper:
    """
    Encapsulates Amazon Redshift cluster operations.
    """

    def __init__(self, redshift_client):
        """
        :param redshift_client: A Boto3 Redshift client.
        """
        self.client = redshift_client


    def delete_cluster(self, cluster_identifier):
        """
        Deletes a cluster.

        :param cluster_identifier: The cluster identifier.
        """
        try:
            self.client.delete_cluster(
                ClusterIdentifier=cluster_identifier, SkipFinalClusterSnapshot=True
            )
        except ClientError as err:
            logging.error(
                "Couldn't delete a cluster. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise

Il codice seguente crea un’istanza dell’oggetto RedshiftWrapper.

    client = boto3.client("redshift")
    redhift_wrapper = RedshiftWrapper(client)

class RedshiftWrapper:
    """
    Encapsulates Amazon Redshift cluster operations.
    """

    def __init__(self, redshift_client):
        """
        :param redshift_client: A Boto3 Redshift client.
        """
        self.client = redshift_client


    def describe_clusters(self, cluster_identifier):
        """
        Describes a cluster.

        :param cluster_identifier: The cluster identifier.
        :return: A list of clusters.
        """
        try:
            kwargs = {}
            if cluster_identifier:
                kwargs["ClusterIdentifier"] = cluster_identifier

            paginator = self.client.get_paginator("describe_clusters")
            clusters = []
            for page in paginator.paginate(**kwargs):
                clusters.extend(page["Clusters"])

            return clusters

        except ClientError as err:
            logging.error(
                "Couldn't describe a cluster. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise

Il codice seguente crea un’istanza dell’oggetto RedshiftWrapper.

    client = boto3.client("redshift")
    redhift_wrapper = RedshiftWrapper(client)

class RedshiftDataWrapper:
    """Encapsulates Amazon Redshift data."""

    def __init__(self, client):
        """
        :param client: A Boto3 RedshiftDataWrapper client.
        """
        self.client = client


    def describe_statement(self, statement_id):
        """
        Describes a SQL statement.

        :param statement_id: The SQL statement identifier.
        :return: The SQL statement result.
        """
        try:
            response = self.client.describe_statement(Id=statement_id)
            return response
        except ClientError as err:
            logging.error(
                "Couldn't describe statement. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise

Il codice seguente crea un’istanza dell’oggetto RedshiftDataWrapper.

    client = boto3.client("redshift-data")
    redshift_data_wrapper = RedshiftDataWrapper(client)

class RedshiftDataWrapper:
    """Encapsulates Amazon Redshift data."""

    def __init__(self, client):
        """
        :param client: A Boto3 RedshiftDataWrapper client.
        """
        self.client = client


    def get_statement_result(self, statement_id):
        """
        Gets the result of a SQL statement.

        :param statement_id: The SQL statement identifier.
        :return: The SQL statement result.
        """
        try:
            result = {
                "Records": [],
            }
            paginator = self.client.get_paginator("get_statement_result")
            for page in paginator.paginate(Id=statement_id):
                if "ColumnMetadata" not in result:
                    result["ColumnMetadata"] = page["ColumnMetadata"]
                result["Records"].extend(page["Records"])
            return result
        except ClientError as err:
            logging.error(
                "Couldn't get statement result. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise

Il codice seguente crea un’istanza dell’oggetto RedshiftDataWrapper.

    client = boto3.client("redshift-data")
    redshift_data_wrapper = RedshiftDataWrapper(client)

class RedshiftWrapper:
    """
    Encapsulates Amazon Redshift cluster operations.
    """

    def __init__(self, redshift_client):
        """
        :param redshift_client: A Boto3 Redshift client.
        """
        self.client = redshift_client


    def modify_cluster(self, cluster_identifier, preferred_maintenance_window):
        """
        Modifies a cluster.

        :param cluster_identifier: The cluster identifier.
        :param preferred_maintenance_window: The preferred maintenance window.
        """
        try:
            self.client.modify_cluster(
                ClusterIdentifier=cluster_identifier,
                PreferredMaintenanceWindow=preferred_maintenance_window,
            )
        except ClientError as err:
            logging.error(
                "Couldn't modify a cluster. Here's why: %s: %s",
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise

Il codice seguente crea un’istanza dell’oggetto RedshiftWrapper.

    client = boto3.client("redshift")
    redhift_wrapper = RedshiftWrapper(client)