Using Cloud Spanner with Cloud Functions

Cloud Spanner


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


This topic uses Cloud Spanner and Cloud Functions, which are billable components of the Google Cloud Platform.

Before you begin

  1. This topic assumes you have a Cloud 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.
  1. Enable the Cloud Functions API.
    Enable the Cloud Functions API

  2. Install and initialize the Cloud SDK.

  3. Update and install gcloud components:

    gcloud components update &&
    gcloud components install beta

  4. Prepare your development environment:

Prepare the application

  1. Clone the sample app repository to your local machine:


    git clone

    Alternatively, you can download the sample as a zip file and extract it.

  2. Change to the directory that contains the Cloud Functions sample code for accessing Cloud Spanner:


    cd nodejs-docs-samples/functions/spanner/

  3. Take a look at the sample code:


    // Imports the Google Cloud client library
    const Spanner = require('@google-cloud/spanner');
    // Instantiates a client
    const spanner = 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.
    exports.get = (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
        .then((results) => {
          const rows = results[0].map((row) => row.toJSON());
          rows.forEach((row) => {
            res.write(`SingerId: ${row.SingerId.value}, AlbumId: ${row.AlbumId.value}, AlbumTitle: ${row.AlbumTitle}\n`);
        .catch((err) => {
            .send(`Error querying Spanner: ${err}`)

    By default, Cloud Functions looks for your code in a file named index.js.

    The function sends a SQL query to fetch all Albums data from your database. The function is executed 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:


gcloud functions deploy get --trigger-http

Function deployment may take up to 2 minutes. You should see output similar to the following when the function is deployed:

availableMemoryMb: 256
entryPoint: get
latestOperation: operations/Y29kZS1wdXJwbGUvdXMtY2VudHJhbDEvaGVsbG9HRVQvdGJkYjdWTl9SUWc
name: projects/[PROJECT_ID]/locations/us-central1/functions/[FUNCTION_NAME]
serviceAccount: [PROJECT_ID]
sourceArchiveUrl: gs://[BUCKET]/
status: READY
timeout: 60s
updateTime: '2017-04-28T23:37:15Z'

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 Functions page in the Google Cloud Platform 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:


curl "" 

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.


To avoid incurring additional charges to your GCP account for the Cloud Spanner and Cloud Functions resources used in this topic:

  1. Delete the instance:

    gcloud spanner instances delete test-instance
  2. Delete the function that you deployed:


    gcloud functions delete get 

What's next

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Cloud Spanner Documentation