/*
* Copyright (C) 2023 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
*
* http://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.
*/
package com.google.cloud.teleport.bigtable;
import com.google.bigtable.v2.Cell;
import com.google.bigtable.v2.Column;
import com.google.bigtable.v2.Family;
import com.google.bigtable.v2.Row;
import com.google.cloud.teleport.bigtable.BigtableToJson.Options;
import com.google.cloud.teleport.metadata.Template;
import com.google.cloud.teleport.metadata.TemplateCategory;
import com.google.cloud.teleport.metadata.TemplateParameter;
import com.google.cloud.teleport.metadata.TemplateParameter.TemplateEnumOption;
import com.google.gson.stream.JsonWriter;
import java.io.IOException;
import java.io.StringWriter;
import java.util.HashMap;
import java.util.Map;
import org.apache.beam.runners.dataflow.options.DataflowPipelineOptions;
import org.apache.beam.sdk.Pipeline;
import org.apache.beam.sdk.PipelineResult;
import org.apache.beam.sdk.io.TextIO;
import org.apache.beam.sdk.io.gcp.bigtable.BigtableIO;
import org.apache.beam.sdk.options.Default;
import org.apache.beam.sdk.options.PipelineOptions;
import org.apache.beam.sdk.options.PipelineOptionsFactory;
import org.apache.beam.sdk.options.ValueProvider;
import org.apache.beam.sdk.transforms.MapElements;
import org.apache.beam.sdk.transforms.SerializableFunction;
import org.apache.beam.sdk.transforms.SimpleFunction;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Dataflow pipeline that exports data from a Cloud Bigtable table to JSON files in GCS. Currently,
* filtering on Cloud Bigtable table is not supported.
*
* <p>Check out <a href=
* "https://github.com/GoogleCloudPlatform/DataflowTemplates/blob/main/v1/README_Cloud_Bigtable_to_GCS_JSON.md">README</a>
* for instructions on how to use or modify this template.
*/
@Template(
name = "Cloud_Bigtable_to_GCS_Json",
category = TemplateCategory.BATCH,
displayName = "Cloud Bigtable to JSON",
description =
"The Bigtable to JSON template is a pipeline that reads data from a Bigtable table and writes it to a Cloud Storage bucket in JSON format",
optionsClass = Options.class,
documentation =
"https://cloud.google.com/dataflow/docs/guides/templates/provided/bigtable-to-json",
contactInformation = "https://cloud.google.com/support",
requirements = {
"The Bigtable table must exist.",
"The output Cloud Storage bucket must exist before running the pipeline."
})
public class BigtableToJson {
private static final Logger LOG = LoggerFactory.getLogger(BigtableToJson.class);
/** Options for the export pipeline. */
public interface Options extends PipelineOptions {
@TemplateParameter.ProjectId(
order = 1,
description = "Project ID",
helpText =
"The ID for the Google Cloud project that contains the Bigtable instance that you want to read data from.")
ValueProvider<String> getBigtableProjectId();
@SuppressWarnings("unused")
void setBigtableProjectId(ValueProvider<String> projectId);
@TemplateParameter.Text(
order = 2,
regexes = {"[a-z][a-z0-9\\-]+[a-z0-9]"},
description = "Instance ID",
helpText = "The ID of the Bigtable instance that contains the table.")
ValueProvider<String> getBigtableInstanceId();
@SuppressWarnings("unused")
void setBigtableInstanceId(ValueProvider<String> instanceId);
@TemplateParameter.Text(
order = 3,
regexes = {"[_a-zA-Z0-9][-_.a-zA-Z0-9]*"},
description = "Table ID",
helpText = "The ID of the Bigtable table to read from.")
ValueProvider<String> getBigtableTableId();
@SuppressWarnings("unused")
void setBigtableTableId(ValueProvider<String> tableId);
@TemplateParameter.GcsWriteFolder(
order = 4,
optional = true,
description = "Cloud Storage directory for storing JSON files",
helpText = "The Cloud Storage path where the output JSON files are stored.",
example = "gs://your-bucket/your-path/")
ValueProvider<String> getOutputDirectory();
@SuppressWarnings("unused")
void setOutputDirectory(ValueProvider<String> outputDirectory);
@TemplateParameter.Text(
order = 5,
description = "JSON file prefix",
helpText =
"The prefix of the JSON file name. For example, \"table1-\". If no value is provided, defaults to `part`.")
@Default.String("part")
ValueProvider<String> getFilenamePrefix();
@SuppressWarnings("unused")
void setFilenamePrefix(ValueProvider<String> filenamePrefix);
@TemplateParameter.Enum(
order = 6,
optional = true,
enumOptions = {@TemplateEnumOption("FLATTEN"), @TemplateEnumOption("NONE")},
description = "User option",
helpText =
"Possible values are `FLATTEN` or `NONE`. `FLATTEN` flattens the row to the single level. `NONE` stores the whole row as a JSON string. Defaults to `NONE`.")
@Default.String("NONE")
String getUserOption();
@SuppressWarnings("unused")
void setUserOption(String userOption);
@TemplateParameter.Text(
order = 7,
optional = true,
parentName = "userOption",
parentTriggerValues = {"FLATTEN"},
description = "Columns aliases",
helpText =
"A comma-separated list of columns that are required for the Vertex AI Vector Search index. The"
+ " columns `id` and `embedding` are required for Vertex AI Vector Search. You can use the notation"
+ " `fromfamily:fromcolumn;to`. For example, if the columns are `rowkey` and `cf:my_embedding`, where"
+ " `rowkey` has a different name than the embedding column, specify `cf:my_embedding;embedding` and,"
+ " `rowkey;id`. Only use this option when the value for `userOption` is `FLATTEN`.")
ValueProvider<String> getColumnsAliases();
@SuppressWarnings("unused")
void setColumnsAliases(ValueProvider<String> value);
}
/**
* Runs a pipeline to export data from a Cloud Bigtable table to JSON files in GCS in JSON format.
*
* @param args arguments to the pipeline
*/
public static void main(String[] args) {
Options options = PipelineOptionsFactory.fromArgs(args).withValidation().as(Options.class);
PipelineResult result = run(options);
// Wait for pipeline to finish only if it is not constructing a template.
if (options.as(DataflowPipelineOptions.class).getTemplateLocation() == null) {
result.waitUntilFinish();
}
LOG.info("Completed pipeline setup");
}
public static PipelineResult run(Options options) {
Pipeline pipeline = Pipeline.create(PipelineUtils.tweakPipelineOptions(options));
BigtableIO.Read read =
BigtableIO.read()
.withProjectId(options.getBigtableProjectId())
.withInstanceId(options.getBigtableInstanceId())
.withTableId(options.getBigtableTableId());
// Do not validate input fields if it is running as a template.
if (options.as(DataflowPipelineOptions.class).getTemplateLocation() != null) {
read = read.withoutValidation();
}
// Concatenating cloud storage folder with file prefix to get complete path
ValueProvider<String> outputFilePrefix = options.getFilenamePrefix();
ValueProvider<String> outputFilePathWithPrefix =
ValueProvider.NestedValueProvider.of(
options.getOutputDirectory(),
(SerializableFunction<String, String>)
folder -> {
if (!folder.endsWith("/")) {
// Appending the slash if not provided by user
folder = folder + "/";
}
return folder + outputFilePrefix.get();
});
String userOption = options.getUserOption();
pipeline
.apply("Read from Bigtable", read)
.apply(
"Transform to JSON",
MapElements.via(
new BigtableToJsonFn(userOption.equals("FLATTEN"), options.getColumnsAliases())))
.apply("Write to storage", TextIO.write().to(outputFilePathWithPrefix).withSuffix(".json"));
return pipeline.run();
}
/** Translates Bigtable {@link Row} to JSON. */
static class BigtableToJsonFn extends SimpleFunction<Row, String> {
private boolean flatten;
private ValueProvider<String> columnsAliases;
public BigtableToJsonFn(boolean flatten, ValueProvider<String> columnsAliases) {
this.flatten = flatten;
this.columnsAliases = columnsAliases;
}
@Override
public String apply(Row row) {
StringWriter stringWriter = new StringWriter();
JsonWriter jsonWriter = new JsonWriter(stringWriter);
try {
if (flatten) {
serializeFlattented(row, jsonWriter);
} else {
serializeUnFlattented(row, jsonWriter);
}
} catch (IOException e) {
throw new RuntimeException(e);
}
return stringWriter.toString();
}
private void serializeUnFlattented(Row row, JsonWriter jsonWriter) throws IOException {
jsonWriter.beginObject();
jsonWriter.name(row.getKey().toStringUtf8());
jsonWriter.beginObject();
for (Family family : row.getFamiliesList()) {
String familyName = family.getName();
jsonWriter.name(familyName);
jsonWriter.beginObject();
for (Column column : family.getColumnsList()) {
for (Cell cell : column.getCellsList()) {
jsonWriter
.name(column.getQualifier().toStringUtf8())
.value(cell.getValue().toStringUtf8());
}
}
jsonWriter.endObject();
}
jsonWriter.endObject();
jsonWriter.endObject();
}
private void serializeFlattented(Row row, JsonWriter jsonWriter) throws IOException {
jsonWriter.beginObject();
Map<String, String> columnsWithAliases = extractColumnsAliases();
maybeAddToJson(jsonWriter, columnsWithAliases, "rowkey", row.getKey().toStringUtf8());
for (Family family : row.getFamiliesList()) {
String familyName = family.getName();
for (Column column : family.getColumnsList()) {
for (Cell cell : column.getCellsList()) {
maybeAddToJson(
jsonWriter,
columnsWithAliases,
familyName + ":" + column.getQualifier().toStringUtf8(),
cell.getValue().toStringUtf8());
}
}
}
jsonWriter.endObject();
}
private void maybeAddToJson(
JsonWriter jsonWriter, Map<String, String> columnsWithAliases, String key, String value)
throws IOException {
if (!columnsWithAliases.isEmpty() && !columnsWithAliases.containsKey(key)) {
return;
}
jsonWriter.name(columnsWithAliases.getOrDefault(key, key)).value(value);
}
private Map<String, String> extractColumnsAliases() {
Map<String, String> columnsWithAliases = new HashMap<>();
if (StringUtils.isBlank(columnsAliases.get())) {
return columnsWithAliases;
}
String[] columnsList = columnsAliases.get().split(",");
for (String columnsWithAlias : columnsList) {
String[] columnWithAlias = columnsWithAlias.split(";");
if (columnWithAlias.length == 2) {
columnsWithAliases.put(columnWithAlias[0], columnWithAlias[1]);
}
}
return columnsWithAliases;
}
}
}
