Bibliotecas de cliente da API BigQuery Migration

Nesta página, você vai aprender a usar as bibliotecas de cliente do Cloud para a API BigQuery Migration. As bibliotecas de cliente facilitam o acesso a APIs do Google Cloud por meio de uma linguagem com suporte. É possível usar as APIs do Google Cloud diretamente fazendo solicitações brutas ao servidor, mas as bibliotecas de cliente oferecem simplificações que reduzem significativamente a quantidade de código que você precisa escrever.

Saiba mais sobre as bibliotecas de cliente do Cloud e as bibliotecas de cliente de APIs do Google mais antigas em Explicação sobre as bibliotecas de cliente.

Instalar a biblioteca de cliente

Go

go get cloud.google.com/go/bigquery

Para mais informações, consulte Como configurar um ambiente de desenvolvimento do Go.

Java

Para mais informações, consulte Como configurar um ambiente de desenvolvimento em Java.

Python

pip install --upgrade google-cloud-bigquery-migration

Para mais informações, consulte Como configurar um ambiente de desenvolvimento em Python.

Configurar a autenticação

Para autenticar as chamadas feitas às APIs do Google Cloud, as bibliotecas de cliente dão suporte ao Application Default Credentials (ADC). As bibliotecas procuram as credenciais em um conjunto de locais definidos e as usam para autenticar as solicitações feitas à API. Com o ADC, é possível disponibilizar credenciais para seu aplicativo em uma variedade de ambientes, como desenvolvimento ou produção local, sem precisar modificar o código do aplicativo.

Em ambientes de produção, a maneira como você configura o ADC depende do serviço e do contexto. Para mais informações, consulte Configurar o Application Default Credentials.

Para um ambiente de desenvolvimento local, é possível configurar o ADC com as credenciais associadas à sua Conta do Google:

  1. Instale e inicialize a gcloud CLI.

    Ao inicializar a gcloud CLI, especifique um projeto do Google Cloud em que você tem permissão para acessar os recursos necessários para o aplicativo.

  2. Configure o ADC:

    gcloud auth application-default login

    Uma tela de login será exibida. Após o login, suas credenciais são armazenadas no arquivo de credenciais local usado pelo ADC.

Usar a biblioteca de cliente

O exemplo a seguir demonstra algumas interações básicas com a API BigQuery Migration.

Go

// Copyright 2021 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.


// The bigquery_migration_quickstart application demonstrates basic usage of the
// BigQuery migration API by executing a workflow that performs a batch SQL
// translation task.
package main

import (
	"context"
	"flag"
	"fmt"
	"log"
	"time"

	migration "cloud.google.com/go/bigquery/migration/apiv2"
	"cloud.google.com/go/bigquery/migration/apiv2/migrationpb"
)

func main() {
	// Define command line flags for controlling the behavior of this quickstart.
	projectID := flag.String("project_id", "", "Cloud Project ID.")
	location := flag.String("location", "us", "BigQuery Migration location used for interactions.")
	outputPath := flag.String("output", "", "Cloud Storage path for translated resources.")
	// Parse flags and do some minimal validation.
	flag.Parse()
	if *projectID == "" {
		log.Fatal("empty --project_id specified, please provide a valid project ID")
	}
	if *location == "" {
		log.Fatal("empty --location specified, please provide a valid location")
	}
	if *outputPath == "" {
		log.Fatalf("empty --output specified, please provide a valid cloud storage path")
	}

	ctx := context.Background()
	migClient, err := migration.NewClient(ctx)
	if err != nil {
		log.Fatalf("migration.NewClient: %v", err)
	}
	defer migClient.Close()

	workflow, err := executeTranslationWorkflow(ctx, migClient, *projectID, *location, *outputPath)
	if err != nil {
		log.Fatalf("workflow execution failed: %v\n", err)
	}

	reportWorkflowStatus(workflow)
}

// executeTranslationWorkflow constructs a migration workflow that performs batch SQL translation.
func executeTranslationWorkflow(ctx context.Context, client *migration.Client, projectID, location, outPath string) (*migrationpb.MigrationWorkflow, error) {

	// Construct the workflow creation request.  In this workflow, we have only a single translation task present.
	req := &migrationpb.CreateMigrationWorkflowRequest{
		Parent: fmt.Sprintf("projects/%s/locations/%s", projectID, location),
		MigrationWorkflow: &migrationpb.MigrationWorkflow{
			DisplayName: "example SQL conversion",
			Tasks: map[string]*migrationpb.MigrationTask{
				"example_conversion": {
					Type: "Translation_Teradata2BQ",
					TaskDetails: &migrationpb.MigrationTask_TranslationConfigDetails{
						TranslationConfigDetails: &migrationpb.TranslationConfigDetails{
							SourceLocation: &migrationpb.TranslationConfigDetails_GcsSourcePath{
								GcsSourcePath: "gs://cloud-samples-data/bigquery/migration/translation/input/",
							},
							TargetLocation: &migrationpb.TranslationConfigDetails_GcsTargetPath{
								GcsTargetPath: outPath,
							},
							SourceDialect: &migrationpb.Dialect{
								DialectValue: &migrationpb.Dialect_TeradataDialect{
									TeradataDialect: &migrationpb.TeradataDialect{
										Mode: migrationpb.TeradataDialect_SQL,
									},
								},
							},
							TargetDialect: &migrationpb.Dialect{
								DialectValue: &migrationpb.Dialect_BigqueryDialect{},
							},
						},
					},
				},
			},
		},
	}

	// Create the workflow using the request.
	workflow, err := client.CreateMigrationWorkflow(ctx, req)
	if err != nil {
		return nil, fmt.Errorf("CreateMigrationWorkflow: %w", err)
	}
	fmt.Printf("workflow created: %s", workflow.GetName())

	// This is an asyncronous process, so we now poll the workflow
	// until completion or a suitable timeout has elapsed.
	timeoutCtx, cancel := context.WithTimeout(ctx, 5*time.Minute)
	defer cancel()
	for {
		select {
		case <-timeoutCtx.Done():
			return nil, fmt.Errorf("task %s didn't complete due to context expiring", workflow.GetName())
		default:
			polledWorkflow, err := client.GetMigrationWorkflow(timeoutCtx, &migrationpb.GetMigrationWorkflowRequest{
				Name: workflow.GetName(),
			})
			if err != nil {
				return nil, fmt.Errorf("polling ended in error: %w", err)
			}
			if polledWorkflow.GetState() == migrationpb.MigrationWorkflow_COMPLETED {
				// polledWorkflow contains the most recent metadata about the workflow, so we return that.
				return polledWorkflow, nil
			}
			// workflow still isn't complete, so sleep briefly before polling again.
			time.Sleep(5 * time.Second)
		}
	}
}

// reportWorkflowStatus prints information about the workflow execution in a more human readable format.
func reportWorkflowStatus(workflow *migrationpb.MigrationWorkflow) {
	fmt.Printf("Migration workflow %s ended in state %s.\n", workflow.GetName(), workflow.GetState().String())
	for k, task := range workflow.GetTasks() {
		fmt.Printf(" - Task %s had id %s", k, task.GetId())
		if task.GetProcessingError() != nil {
			fmt.Printf(" with processing error: %s", task.GetProcessingError().GetReason())
		}
		fmt.Println()
	}
}

Python

# Copyright 2022 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


def create_migration_workflow(
    gcs_input_path: str, gcs_output_path: str, project_id: str
) -> None:
    """Creates a migration workflow of a Batch SQL Translation and prints the response."""

    from google.cloud import bigquery_migration_v2

    parent = f"projects/{project_id}/locations/us"

    # Construct a BigQuery Migration client object.
    client = bigquery_migration_v2.MigrationServiceClient()

    # Set the source dialect to Teradata SQL.
    source_dialect = bigquery_migration_v2.Dialect()
    source_dialect.teradata_dialect = bigquery_migration_v2.TeradataDialect(
        mode=bigquery_migration_v2.TeradataDialect.Mode.SQL
    )

    # Set the target dialect to BigQuery dialect.
    target_dialect = bigquery_migration_v2.Dialect()
    target_dialect.bigquery_dialect = bigquery_migration_v2.BigQueryDialect()

    # Prepare the config proto.
    translation_config = bigquery_migration_v2.TranslationConfigDetails(
        gcs_source_path=gcs_input_path,
        gcs_target_path=gcs_output_path,
        source_dialect=source_dialect,
        target_dialect=target_dialect,
    )

    # Prepare the task.
    migration_task = bigquery_migration_v2.MigrationTask(
        type_="Translation_Teradata2BQ", translation_config_details=translation_config
    )

    # Prepare the workflow.
    workflow = bigquery_migration_v2.MigrationWorkflow(
        display_name="demo-workflow-python-example-Teradata2BQ"
    )

    workflow.tasks["translation-task"] = migration_task  # type: ignore

    # Prepare the API request to create a migration workflow.
    request = bigquery_migration_v2.CreateMigrationWorkflowRequest(
        parent=parent,
        migration_workflow=workflow,
    )

    response = client.create_migration_workflow(request=request)

    print("Created workflow:")
    print(response.display_name)
    print("Current state:")
    print(response.State(response.state))


Outros recursos

Go

Confira na lista a seguir os links para mais recursos relacionados à biblioteca de cliente para Go:

Java

Confira na lista a seguir os links para mais recursos relacionados à biblioteca de cliente para Java:

Python

Confira na lista a seguir os links para mais recursos relacionados à biblioteca de cliente para Python:

A seguir

Para mais informações, consulte a introdução ao serviço BigQuery Migration.