Cloud Functions (1st gen) has been renamed to Cloud Run functions (1st gen). Switch to the Cloud Run functions documentation.

Using Spanner with Cloud Run functions (1st gen)

Objectives

Write, deploy, and trigger an HTTP Cloud Run function that accesses Spanner.

Costs

This document uses Spanner and Cloud Run functions, which are billable components of Google Cloud.

For information on the cost of using Spanner, see Spanner pricing.
For information on the cost of using Cloud Run functions, including free invocations, see Cloud Run functions pricing.

Before you begin

This document assumes you have a Spanner instance named test-instance and a database named example-db that uses the music application schema. For instructions on creating an instance and database with the music application schema, see Quickstart using the console or the tutorials for Getting Started in Go, Java, Node.js, or Python.

Note: After this step, you should have two tables, Singers and Albums, in your database with the sample data specified in the music application schema.
Enable the Cloud Run functions and Cloud Build APIs.

Enable the APIs
Install and initialize the gcloud CLI.

If you already have the gcloud CLI installed, update it by running the following command:
```
gcloud components update
```
Prepare your development environment:

Node.js

Go to the Node.js setup guide

Python

Go to the Python setup guide

Go

Go to the Go setup guide

Java

Go to the Java setup guide

Prepare the application

Clone the sample app repository to your local machine:
Node.js
```
git clone https://github.com/GoogleCloudPlatform/nodejs-docs-samples.git
```
Alternatively, you can download the sample as a zip file and extract it.
Python
```
git clone https://github.com/GoogleCloudPlatform/python-docs-samples.git
```
Alternatively, you can download the sample as a zip file and extract it.
Go
```
git clone https://github.com/GoogleCloudPlatform/golang-samples.git
```
Alternatively, you can download the sample as a zip file and extract it.
Java
```
git clone https://github.com/GoogleCloudPlatform/java-docs-samples.git
```
Alternatively, you can download the sample as a zip file and extract it.

Change to the directory that contains the Cloud Run functions sample code for accessing Spanner:

Node.js

cd nodejs-docs-samples/functions/spanner/

Python

cd python-docs-samples/functions/spanner/

Go

cd golang-samples/functions/spanner/

Java

cd java-docs-samples/functions/spanner/

Take a look at the sample code:

Node.js

// Imports the Google Cloud client library
const {Spanner} = require('@google-cloud/spanner');

// Imports the functions framework to register your HTTP function
const functions = require('@google-cloud/functions-framework');

// Instantiates a client
const spanner = new Spanner();

// Your Cloud Spanner instance ID
const instanceId = 'test-instance';

// Your Cloud Spanner database ID
const databaseId = 'example-db';

/**
 * HTTP Cloud Function.
 *
 * @param {Object} req Cloud Function request context.
 * @param {Object} res Cloud Function response context.
 */
functions.http('spannerQuickstart', async (req, res) => {
  // Gets a reference to a Cloud Spanner instance and database
  const instance = spanner.instance(instanceId);
  const database = instance.database(databaseId);

  // The query to execute
  const query = {
    sql: 'SELECT * FROM Albums',
  };

  // Execute the query
  try {
    const results = await database.run(query);
    const rows = results[0].map(row => row.toJSON());
    rows.forEach(row => {
      res.write(
        `SingerId: ${row.SingerId}, ` +
          `AlbumId: ${row.AlbumId}, ` +
          `AlbumTitle: ${row.AlbumTitle}\n`
      );
    });
    res.status(200).end();
  } catch (err) {
    res.status(500).send(`Error querying Spanner: ${err}`);
  }
});

Python

import functions_framework
from google.cloud import spanner

instance_id = "test-instance"
database_id = "example-db"

client = spanner.Client()
instance = client.instance(instance_id)
database = instance.database(database_id)


@functions_framework.http
def spanner_read_data(request):
    query = "SELECT * FROM Albums"

    outputs = []
    with database.snapshot() as snapshot:
        results = snapshot.execute_sql(query)

        for row in results:
            output = "SingerId: {}, AlbumId: {}, AlbumTitle: {}".format(*row)
            outputs.append(output)

    return "\n".join(outputs)

Go


// Package spanner contains an example of using Spanner from a Cloud Function.
package spanner

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"sync"

	"cloud.google.com/go/spanner"
	"github.com/GoogleCloudPlatform/functions-framework-go/functions"
	"google.golang.org/api/iterator"
)

// client is a global Spanner client, to avoid initializing a new client for
// every request.
var client *spanner.Client
var clientOnce sync.Once

// db is the name of the database to query.
var db = "projects/my-project/instances/my-instance/databases/example-db"

func init() {
	functions.HTTP("HelloSpanner", HelloSpanner)
}

// HelloSpanner is an example of querying Spanner from a Cloud Function.
func HelloSpanner(w http.ResponseWriter, r *http.Request) {
	clientOnce.Do(func() {
		// Declare a separate err variable to avoid shadowing client.
		var err error
		client, err = spanner.NewClient(context.Background(), db)
		if err != nil {
			http.Error(w, "Error initializing database", http.StatusInternalServerError)
			log.Printf("spanner.NewClient: %v", err)
			return
		}
	})

	fmt.Fprintln(w, "Albums:")
	stmt := spanner.Statement{SQL: `SELECT SingerId, AlbumId, AlbumTitle FROM Albums`}
	iter := client.Single().Query(r.Context(), stmt)
	defer iter.Stop()
	for {
		row, err := iter.Next()
		if err == iterator.Done {
			return
		}
		if err != nil {
			http.Error(w, "Error querying database", http.StatusInternalServerError)
			log.Printf("iter.Next: %v", err)
			return
		}
		var singerID, albumID int64
		var albumTitle string
		if err := row.Columns(&singerID, &albumID, &albumTitle); err != nil {
			http.Error(w, "Error parsing database response", http.StatusInternalServerError)
			log.Printf("row.Columns: %v", err)
			return
		}
		fmt.Fprintf(w, "%d %d %s\n", singerID, albumID, albumTitle)
	}
}

Java

import com.google.api.client.http.HttpStatusCodes;
import com.google.cloud.functions.HttpFunction;
import com.google.cloud.functions.HttpRequest;
import com.google.cloud.functions.HttpResponse;
import com.google.cloud.spanner.DatabaseClient;
import com.google.cloud.spanner.DatabaseId;
import com.google.cloud.spanner.LazySpannerInitializer;
import com.google.cloud.spanner.ResultSet;
import com.google.cloud.spanner.SpannerException;
import com.google.cloud.spanner.SpannerOptions;
import com.google.cloud.spanner.Statement;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.MoreObjects;
import java.io.PrintWriter;
import java.util.logging.Level;
import java.util.logging.Logger;

// HelloSpanner is an example of querying Spanner from a Cloud Function.
public class HelloSpanner implements HttpFunction {
  private static final Logger logger = Logger.getLogger(HelloSpanner.class.getName());

  // TODO<developer>: Set these environment variables.
  private static final String SPANNER_INSTANCE_ID =
      MoreObjects.firstNonNull(System.getenv("SPANNER_INSTANCE"), "my-instance");
  private static final String SPANNER_DATABASE_ID =
      MoreObjects.firstNonNull(System.getenv("SPANNER_DATABASE"), "example-db");

  private static final DatabaseId databaseId =
      DatabaseId.of(
          SpannerOptions.getDefaultProjectId(),
          SPANNER_INSTANCE_ID,
          SPANNER_DATABASE_ID);

  // The LazySpannerInitializer instance is shared across all instances of the HelloSpanner class.
  // It will create a Spanner instance the first time one is requested, and continue to return that
  // instance for all subsequent requests.
  private static final LazySpannerInitializer SPANNER_INITIALIZER = new LazySpannerInitializer();

  @VisibleForTesting
  DatabaseClient getClient() throws Throwable {
    return SPANNER_INITIALIZER.get().getDatabaseClient(databaseId);
  }

  @Override
  public void service(HttpRequest request, HttpResponse response) throws Exception {
    var writer = new PrintWriter(response.getWriter());
    try {
      DatabaseClient client = getClient();
      try (ResultSet rs =
          client
              .singleUse()
              .executeQuery(Statement.of("SELECT SingerId, AlbumId, AlbumTitle FROM Albums"))) {
        writer.printf("Albums:%n");
        while (rs.next()) {
          writer.printf(
              "%d %d %s%n",
              rs.getLong("SingerId"), rs.getLong("AlbumId"), rs.getString("AlbumTitle"));
        }
      } catch (SpannerException e) {
        writer.printf("Error querying database: %s%n", e.getMessage());
        response.setStatusCode(HttpStatusCodes.STATUS_CODE_SERVER_ERROR, e.getMessage());
      }
    } catch (Throwable t) {
      logger.log(Level.SEVERE, "Spanner example failed", t);
      writer.printf("Error setting up Spanner: %s%n", t.getMessage());
      response.setStatusCode(HttpStatusCodes.STATUS_CODE_SERVER_ERROR, t.getMessage());
    }
  }
}

The function sends a SQL query to fetch all Albums data from your database. The function executes when you make an HTTP request to the function's endpoint.

Deploy the function

To deploy the function with an HTTP trigger, run the following command in the spanner directory:

Node.js

gcloud functions deploy get \
--runtime nodejs20 --trigger-http

Use the --runtime flag to specify the runtime ID of a supported Node.js version to run your function.

Python

gcloud functions deploy spanner_read_data \
--runtime python312 --trigger-http

Use the --runtime flag to specify the runtime ID of a supported Python version to run your function.

Go

gcloud functions deploy HelloSpanner \
--runtime go121 --trigger-http

Use the --runtime flag to specify the runtime ID of a supported Go version to run your function.

Java

gcloud functions deploy java-spanner-function \
--entry-point functions.HelloSpanner \
--runtime java17 \
--memory 512MB --trigger-http

Use the --runtime flag to specify the runtime ID of a supported Java version to run your function.

Function deployment might take up to two minutes.

Note the url value returned when your function finishes deploying. You will use it when you trigger the function.

You can view your deployed functions on the Cloud Run functions page in the Google Cloud console. You can also create and edit functions on that page, and get details and diagnostics for your functions.

Trigger the function

Make an HTTP request to your function:

Node.js

curl "https://REGION-PROJECT_ID.cloudfunctions.net/get"

Python

curl "https://REGION-PROJECT_ID.cloudfunctions.net/spanner_read_data"

Go

curl "https://REGION-PROJECT_ID.cloudfunctions.net/HelloSpanner"

Java

curl "https://REGION-PROJECT_ID.cloudfunctions.net/java-spanner-function"

where REGION and PROJECT_ID match the values that are visible in your terminal when your function finishes deploying. You should see output that shows the results of the SQL query, assuming you worked through a Getting Started tutorial and populated the database:

SingerId: 2, AlbumId: 2, AlbumTitle: Forever Hold Your Peace
SingerId: 1, AlbumId: 2, AlbumTitle: Go, Go, Go
SingerId: 2, AlbumId: 1, AlbumTitle: Green
SingerId: 2, AlbumId: 3, AlbumTitle: Terrified
SingerId: 1, AlbumId: 1, AlbumTitle: Total Junk

You can also visit the function's URL in your browser to see the result of your SQL query.

Cleanup

To avoid incurring additional charges to your Google Cloud account for the Spanner and Cloud Run functions resources used in this document, do the following:

Delete the instance:

gcloud spanner instances delete test-instance

Delete the function that you deployed:

Node.js

gcloud functions delete get

Python

gcloud functions delete spanner_read_data

Go

gcloud functions delete HelloSpanner

Java

gcloud functions delete java-spanner-function

Using Spanner with Cloud Run functions (1st gen)

Objectives

Costs

Before you begin

Node.js

Python

Go

Java

Prepare the application

Node.js

Python

Go

Java

Node.js

Python

Go

Java

Node.js

Python

Go

Java

Deploy the function

Node.js

Python

Go

Java

Trigger the function

Node.js

Python

Go

Java

Cleanup

Node.js

Python

Go

Java

What's next