Pub/Sub to Redis template

Beta

This feature is subject to the "Pre-GA Offerings Terms" in the General Service Terms section of the Service Specific Terms. Pre-GA features are available "as is" and might have limited support. For more information, see the launch stage descriptions.

The Pub/Sub to Redis template is a streaming pipeline that reads messages from a Pub/Sub subscription and writes the message payload to Redis. The most common use case of this template is to export logs to Redis Enterprise for advanced search-based log analysis in real time.

• Before writing to Redis, you can apply a JavaScript user-defined function to the message payload.
• Any messages that experience processing failures are forwarded to a Pub/Sub unprocessed topic for further troubleshooting and reprocessing.
• For added security, enable an SSL connection when setting up your database endpoint connection. This template doesn't support mutual TLS.

Pipeline requirements

• The source Pub/Sub subscription must exist prior to running the pipeline.
• The Pub/Sub unprocessed topic must exist prior to running the pipeline.
• The Redis database endpoint must be accessible from the Dataflow workers' subnetwork.

Template parameters

Required parameters

• inputSubscription : The Pub/Sub subscription to read the input from, in the format projects/<PROJECT_ID>/subscriptions/<SUBSCRIPTION_ID>. (Example: projects/your-project-id/subscriptions/your-subscription-name).
• redisHost : The Redis database host. (Example: your.cloud.db.redislabs.com). Defaults to: 127.0.0.1.
• redisPort : The Redis database port. (Example: 12345). Defaults to: 6379.
• redisPassword : The Redis database password. Defaults to empty.

Optional parameters

• sslEnabled : The Redis database SSL parameter. Defaults to: false.
• redisSinkType : The Redis sink. Supported values are STRING_SINK, HASH_SINK, STREAMS_SINK, and LOGGING_SINK. (Example: STRING_SINK). Defaults to: STRING_SINK.
• connectionTimeout : The Redis connection timeout in milliseconds. (Example: 2000). Defaults to: 2000.
• ttl : The key expiration time in seconds. The ttl default for HASH_SINK is -1, which means it never expires.
• javascriptTextTransformGcsPath : The Cloud Storage URI of the .js file that defines the JavaScript user-defined function (UDF) to use. (Example: gs://my-bucket/my-udfs/my_file.js).
• javascriptTextTransformFunctionName : The name of the JavaScript user-defined function (UDF) to use. For example, if your JavaScript function code is myTransform(inJson) { /*...do stuff...*/ }, then the function name is myTransform. For sample JavaScript UDFs, see UDF Examples (https://github.com/GoogleCloudPlatform/DataflowTemplates#udf-examples).
• javascriptTextTransformReloadIntervalMinutes : Specifies how frequently to reload the UDF, in minutes. If the value is greater than 0, Dataflow periodically checks the UDF file in Cloud Storage, and reloads the UDF if the file is modified. This parameter allows you to update the UDF while the pipeline is running, without needing to restart the job. If the value is 0, UDF reloading is disabled. The default value is 0.

User-defined function

Optionally, you can extend this template by writing a user-defined function (UDF). The template calls the UDF for each input element. Element payloads are serialized as JSON strings. For more information, see Create user-defined functions for Dataflow templates.

Function specification

The UDF has the following specification:

• Input: JSON string
• Output: a string or a stringified JSON object

Run the template

Console

1. Go to the Dataflow Create job from template page.
Go to Create job from template
2. In the Job name field, enter a unique job name.
3. Optional: For Regional endpoint, select a value from the drop-down menu. The default region is us-central1.

   For a list of regions where you can run a Dataflow job, see Dataflow locations.

4. From the Dataflow template drop-down menu, select the Pub/Sub to Redis template.
5. In the provided parameter fields, enter your parameter values.
6. Click Run job.

gcloud

Note: To use the Google Cloud CLI to run flex templates, you must have Google Cloud CLI version 284.0.0 or later.

In your shell or terminal, run the template:

gcloud dataflow flex-template run JOB_NAME \
    --template-file-gcs-location=gs://dataflow-templates-REGION_NAME/VERSION/flex/Cloud_PubSub_to_Redis \
    --project=PROJECT_ID \
    --region=REGION_NAME \
    --parameters \
       inputSubscription=INPUT_SUBSCRIPTION,\
       redisHost=REDIS_HOST,\
       redisPort=REDIS_PORT,\
       redisPassword=REDIS_PASSWORD,\

Replace the following:

• JOB_NAME: a unique job name of your choice
• VERSION: the version of the template that you want to use

  You can use the following values:

  • latest to use the latest version of the template, which is available in the non-dated parent folder in the bucket— gs://dataflow-templates-REGION_NAME/latest/
  • the version name, like 2023-09-12-00_RC00, to use a specific version of the template, which can be found nested in the respective dated parent folder in the bucket— gs://dataflow-templates-REGION_NAME/
  Caution: The latest version of templates might update with breaking changes. Your production environments should use templates kept in the most recent dated parent folder to prevent these breaking changes from affecting your production workflows.
• REGION_NAME: the region where you want to deploy your Dataflow job—for example, us-central1
• INPUT_SUBSCRIPTION: the Pub/Sub input subscription
• REDIS_HOST: the Redis DB Host
• REDIS_PORT: the Redis DB Port
• REDIS_PASSWORD: the Redis DB Password

API

To run the template using the REST API, send an HTTP POST request. For more information on the API and its authorization scopes, see projects.templates.launch.

POST https://dataflow.googleapis.com/v1b3/projects/PROJECT_ID/locations/LOCATION/flexTemplates:launch
{
   "launchParameter": {
     "jobName": "JOB_NAME",
     "parameters": {
       "inputSubscription": "INPUT_SUBSCRIPTION",
       "redisHost": "REDIS_HOST",
       "redisPort": "REDIS_PORT",
       "redisPassword": "REDIS_PASSWORD",
     },
     "containerSpecGcsPath": "gs://dataflow-templates-LOCATION/VERSION/flex/Cloud_PubSub_to_Redis",
     "environment": { "maxWorkers": "10" }
  }
}

Replace the following:

• PROJECT_ID: the Google Cloud project ID where you want to run the Dataflow job
• JOB_NAME: a unique job name of your choice
• VERSION: the version of the template that you want to use

  You can use the following values:

  • latest to use the latest version of the template, which is available in the non-dated parent folder in the bucket— gs://dataflow-templates-REGION_NAME/latest/
  • the version name, like 2023-09-12-00_RC00, to use a specific version of the template, which can be found nested in the respective dated parent folder in the bucket— gs://dataflow-templates-REGION_NAME/
  Caution: The latest version of templates might update with breaking changes. Your production environments should use templates kept in the most recent dated parent folder to prevent these breaking changes from affecting your production workflows.
• LOCATION: the region where you want to deploy your Dataflow job—for example, us-central1
• INPUT_SUBSCRIPTION: the Pub/Sub input subscription
• REDIS_HOST: the Redis DB Host
• REDIS_PORT: the Redis DB Port
• REDIS_PASSWORD: the Redis DB Password

Template source code

Java

/*
 * 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.v2.templates;

import static com.google.cloud.teleport.v2.templates.PubSubToRedis.RedisSinkType.HASH_SINK;
import static com.google.cloud.teleport.v2.templates.PubSubToRedis.RedisSinkType.LOGGING_SINK;
import static com.google.cloud.teleport.v2.templates.PubSubToRedis.RedisSinkType.STREAMS_SINK;
import static com.google.cloud.teleport.v2.templates.PubSubToRedis.RedisSinkType.STRING_SINK;

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.cloud.teleport.v2.common.UncaughtExceptionLogger;
import com.google.cloud.teleport.v2.templates.io.RedisHashIO;
import com.google.cloud.teleport.v2.templates.transforms.MessageTransformation;
import com.google.cloud.teleport.v2.transforms.JavascriptTextTransformer;
import java.util.Map;
import org.apache.beam.sdk.Pipeline;
import org.apache.beam.sdk.PipelineResult;
import org.apache.beam.sdk.io.gcp.pubsub.PubsubMessage;
import org.apache.beam.sdk.io.redis.RedisConnectionConfiguration;
import org.apache.beam.sdk.io.redis.RedisIO;
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.Validation;
import org.apache.beam.sdk.options.ValueProvider;
import org.apache.beam.sdk.transforms.MapElements;
import org.apache.beam.sdk.transforms.ParDo;
import org.apache.beam.sdk.values.KV;
import org.apache.beam.sdk.values.PCollection;
import org.apache.beam.sdk.values.TypeDescriptors;
import org.checkerframework.checker.initialization.qual.Initialized;
import org.checkerframework.checker.nullness.qual.NonNull;
import org.checkerframework.checker.nullness.qual.UnknownKeyFor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * The {@link PubSubToRedis} pipeline is a streaming pipeline which ingests data in Bytes from
 * PubSub, and inserts resulting records as KV in Redis.
 *
 * <p><b>Pipeline Requirements</b>
 *
 * <ul>
 *   <li>The PubSub topic and subscriptions exist
 *   <li>The Redis is up and running
 * </ul>
 *
 * <p><b>Example Usage</b>
 *
 * <pre>
 * # Set the pipeline vars
 * PROJECT_NAME=my-project
 * BUCKET_NAME=my-bucket
 * INPUT_SUBSCRIPTION=my-subscription
 * REDIS_HOST=my-host
 * REDIS_PORT=my-port
 * REDIS_PASSWORD=my-pwd
 *
 * mvn compile exec:java \
 *  -Dexec.mainClass=com.google.cloud.teleport.v2.templates.PubSubToRedis \
 *  -Dexec.cleanupDaemonThreads=false \
 *  -Dexec.args=" \
 *  --project=${PROJECT_NAME} \
 *  --stagingLocation=gs://${BUCKET_NAME}/staging \
 *  --tempLocation=gs://${BUCKET_NAME}/temp \
 *  --runner=DataflowRunner \
 *  --inputSubscription=${INPUT_SUBSCRIPTION} \
 *  --redisHost=${REDIS_HOST}
 *  --redisPort=${REDIS_PORT}
 *  --redisPassword=${REDIS_PASSWORD}"
 * </pre>
 */
@Template(
    name = "Cloud_PubSub_to_Redis",
    category = TemplateCategory.STREAMING,
    displayName = "Pub/Sub to Redis",
    description = {
      "The Pub/Sub to Redis template is a streaming pipeline that reads messages from a Pub/Sub subscription and "
          + "writes the message payload to Redis. The most common use case of this template is to export logs to Redis "
          + "Enterprise for advanced search-based log analysis in real time.",
      "Before writing to Redis, you can apply a JavaScript user-defined function to the message payload. Any "
          + "messages that experience processing failures are forwarded to a Pub/Sub unprocessed topic for further "
          + "troubleshooting and reprocessing.",
      "For added security, enable an SSL connection when setting up your database endpoint connection."
    },
    optionsClass = PubSubToRedis.PubSubToRedisOptions.class,
    flexContainerName = "pubsub-to-redis",
    contactInformation = "https://github.com/GoogleCloudPlatform/DataflowTemplates/issues",
    documentation =
        "https://cloud.google.com/dataflow/docs/guides/templates/provided/pubsub-to-redis",
    requirements = {
      "The source Pub/Sub subscription must exist prior to running the pipeline.",
      "The Pub/Sub unprocessed topic must exist prior to running the pipeline.",
      "The Redis database endpoint must be accessible from the Dataflow workers' subnetwork.",
    },
    preview = true,
    streaming = true,
    supportsAtLeastOnce = true)
public class PubSubToRedis {
  /*
   * Options supported by {@link PubSubToRedis}
   *
   * <p>Inherits standard configuration options.
   */

  /** The log to output status messages to. */
  private static final Logger LOG = LoggerFactory.getLogger(PubSubToRedis.class);

  /**
   * The {@link PubSubToRedisOptions} class provides the custom execution options passed by the
   * executor at the command-line.
   *
   * <p>Inherits standard configuration options, options from {@link
   * JavascriptTextTransformer.JavascriptTextTransformerOptions}.
   */
  public interface PubSubToRedisOptions
      extends JavascriptTextTransformer.JavascriptTextTransformerOptions, PipelineOptions {
    @TemplateParameter.PubsubSubscription(
        order = 1,
        description = "Pub/Sub input subscription",
        helpText =
            "The Pub/Sub subscription to read the input from, in the format"
                + " projects/<PROJECT_ID>/subscriptions/<SUBSCRIPTION_ID>.",
        example = "projects/your-project-id/subscriptions/your-subscription-name")
    String getInputSubscription();

    void setInputSubscription(String value);

    @TemplateParameter.Text(
        order = 2,
        description = "Redis DB Host",
        helpText = "The Redis database host.",
        example = "your.cloud.db.redislabs.com")
    @Default.String("127.0.0.1")
    @Validation.Required
    String getRedisHost();

    void setRedisHost(String redisHost);

    @TemplateParameter.Integer(
        order = 3,
        description = "Redis DB Port",
        helpText = "The Redis database port.",
        example = "12345")
    @Default.Integer(6379)
    @Validation.Required
    int getRedisPort();

    void setRedisPort(int redisPort);

    @TemplateParameter.Password(
        order = 4,
        description = "Redis DB Password",
        helpText = "The Redis database password. Defaults to empty.")
    @Default.String("")
    @Validation.Required
    String getRedisPassword();

    void setRedisPassword(String redisPassword);

    @TemplateParameter.Boolean(
        order = 5,
        optional = true,
        description = "Redis ssl enabled",
        helpText = "The Redis database SSL parameter.")
    @Default.Boolean(false)
    @UnknownKeyFor
    @NonNull
    @Initialized
    ValueProvider<@UnknownKeyFor @NonNull @Initialized Boolean> getSslEnabled();

    void setSslEnabled(ValueProvider<Boolean> sslEnabled);

    @TemplateParameter.Enum(
        order = 6,
        optional = true,
        enumOptions = {
          @TemplateEnumOption("STRING_SINK"),
          @TemplateEnumOption("HASH_SINK"),
          @TemplateEnumOption("STREAMS_SINK"),
          @TemplateEnumOption("LOGGING_SINK")
        },
        description = "Redis sink to write",
        helpText =
            "The Redis sink. Supported values are `STRING_SINK, HASH_SINK, STREAMS_SINK, and LOGGING_SINK`.",
        example = "STRING_SINK")
    @Default.Enum("STRING_SINK")
    RedisSinkType getRedisSinkType();

    void setRedisSinkType(RedisSinkType redisSinkType);

    @TemplateParameter.Integer(
        order = 7,
        optional = true,
        description = "Redis connection timeout in milliseconds",
        helpText = "The Redis connection timeout in milliseconds. ",
        example = "2000")
    @Default.Integer(2000)
    int getConnectionTimeout();

    void setConnectionTimeout(int timeout);

    @TemplateParameter.Long(
        order = 8,
        optional = true,
        parentName = "redisSinkType",
        parentTriggerValues = {"HASH_SINK", "LOGGING_SINK"},
        description =
            "Hash key expiration time in sec (ttl), supported only for HASH_SINK and LOGGING_SINK",
        helpText =
            "The key expiration time in seconds. The `ttl` default for `HASH_SINK` is -1, which means it never expires.")
    @Default.Long(-1L)
    Long getTtl();

    void setTtl(Long ttl);
  }

  /** Allowed list of sink types. */
  public enum RedisSinkType {
    HASH_SINK,
    LOGGING_SINK,
    STREAMS_SINK,
    STRING_SINK
  }

  /**
   * Main entry point for executing the pipeline.
   *
   * @param args The command-line arguments to the pipeline.
   */
  public static void main(String[] args) {
    UncaughtExceptionLogger.register();

    // Parse the user options passed from the command-line.
    PubSubToRedisOptions options =
        PipelineOptionsFactory.fromArgs(args).withValidation().as(PubSubToRedisOptions.class);
    run(options);
  }

  /**
   * Runs the pipeline with the supplied options.
   *
   * @param options The execution parameters to the pipeline.
   * @return The result of the pipeline execution.
   */
  public static PipelineResult run(PubSubToRedisOptions options) {

    // Create the pipeline
    Pipeline pipeline = Pipeline.create(options);

    PCollection<PubsubMessage> input;

    RedisConnectionConfiguration redisConnectionConfiguration =
        RedisConnectionConfiguration.create()
            .withHost(options.getRedisHost())
            .withPort(options.getRedisPort())
            .withAuth(options.getRedisPassword())
            .withTimeout(options.getConnectionTimeout())
            .withSSL(options.getSslEnabled());

    /*
     * Steps: 1) Read PubSubMessage with attributes and messageId from input PubSub subscription.
     *        2) Extract PubSubMessage message to PCollection<String>.
     *        3) Transform PCollection<String> to PCollection<KV<String, String>> so it can be consumed by RedisIO
     *        4) Write to Redis using SET
     *
     */

    LOG.info(
        "Starting PubSub-To-Redis Pipeline. Reading from subscription: {}",
        options.getInputSubscription());

    input =
        pipeline.apply(
            "Read PubSub Events",
            MessageTransformation.readFromPubSub(options.getInputSubscription()));

    if (options.getRedisSinkType().equals(STRING_SINK)) {
      PCollection<String> pCollectionString =
          input.apply(
              "Map to Redis String", ParDo.of(new MessageTransformation.MessageToRedisString()));

      PCollection<KV<String, String>> kvStringCollection =
          pCollectionString.apply(
              "Transform to String KV",
              MapElements.into(
                      TypeDescriptors.kvs(TypeDescriptors.strings(), TypeDescriptors.strings()))
                  .via(record -> KV.of(MessageTransformation.key, record)));

      kvStringCollection.apply(
          "Write to " + STRING_SINK.name(),
          RedisIO.write()
              .withMethod(RedisIO.Write.Method.SET)
              .withConnectionConfiguration(redisConnectionConfiguration));
    }
    if (options.getRedisSinkType().equals(HASH_SINK)) {
      PCollection<KV<String, KV<String, String>>> pCollectionHash =
          input.apply(
              "Map to Redis Hash", ParDo.of(new MessageTransformation.MessageToRedisHash()));

      pCollectionHash.apply(
          "Write to " + HASH_SINK.name(),
          RedisHashIO.write()
              .withConnectionConfiguration(redisConnectionConfiguration)
              .withTtl(options.getTtl()));
    }
    if (options.getRedisSinkType().equals(LOGGING_SINK)) {
      PCollection<KV<String, KV<String, String>>> pCollectionHash =
          input.apply(
              "Map to Redis Logs", ParDo.of(new MessageTransformation.MessageToRedisLogs()));

      pCollectionHash.apply(
          "Write to " + LOGGING_SINK.name(),
          RedisHashIO.write()
              .withConnectionConfiguration(redisConnectionConfiguration)
              .withTtl(options.getTtl()));
    }
    if (options.getRedisSinkType().equals(STREAMS_SINK)) {
      PCollection<KV<String, Map<String, String>>> pCollectionStreams =
          input.apply(
              "Map to Redis Streams", ParDo.of(new MessageTransformation.MessageToRedisStreams()));

      pCollectionStreams.apply(
          "Write to " + STREAMS_SINK.name(),
          RedisIO.writeStreams().withConnectionConfiguration(redisConnectionConfiguration));
    }
    // Execute the pipeline and return the result.
    return pipeline.run();
  }
}

What's next

• Learn about Dataflow templates.
• See the list of Google-provided templates.