// 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"
migrationpb "google.golang.org/genproto/googleapis/cloud/bigquery/migration/v2"
)
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", 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: %v", err)
}
// 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: %v", 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()
}
}
