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Yandex Managed Service for YDB

Connecting to a YDB database from a Yandex Cloud Functions function in Node.js

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In this scenario, you'll create a function with an application in Node.js, which runs a simple query against a YDB database. You deploy the application using Bash scripts and use the tcs command to compile.

A function with an associated service account is authorized in YDB via the metadata service.

The application creates a YDB database connection driver, a session, and a transaction, and runs a query using the ydb library. This library is installed as a dependency when creating a function version. The DB connection parameters are passed to the application via environment variables.

Before you start

Before working, you need to register in Yandex Cloud and create a billing account:

  1. Go to the management console. Then log in to Yandex Cloud or sign up if don't already have an account.
  2. On the billing page, make sure you linked a billing account, and it has the ACTIVE or TRIAL_ACTIVE status. If you don't have a billing account, create one.

If you have an active billing account, you can create or select a folder to run your VM in from the Yandex Cloud page.

Learn more about clouds and folders.

The infrastructure support cost for this scenario includes:

Prepare the environment

  1. Clone the examples repository using Git.
  2. Install and initialize the following software programs:
  3. Install dependencies by running the command below: 
    npm install

Create a service account

  1. In the management console, select the folder where you want to create a service account.

  2. Go to the Service accounts tab.

  3. Click Create service account.

  4. Enter a name for the service account, such as sa-function. Naming requirements:

    • The length can be from 3 to 63 characters.
    • It may contain lowercase Latin letters, numbers, and hyphens.
    • The first character must be a letter. The last character can't be a hyphen.

  5. Click Add role and choose the editor role.

  6. Click Create.

Create a YDB database

  1. In the management console, select the folder where you want to create a database.

  2. In the list of services, select Managed Service for YDB.

  3. Click Create database.

  4. Enter a name for the database. Naming requirements:

    • The length can be from 3 to 63 characters.
    • It may contain lowercase Latin letters, numbers, and hyphens.
    • The first character must be a letter. The last character can't be a hyphen.

  5. Under Database type, select the Serverless option.

  6. Click Create database.

    Wait until the database starts. When a database is being created, it has the Provisioning status. When it's ready for use, the status changes to Running.

  7. Click on the name of the created database.

  8. Save the values of the following fields:

    • Endpoint and Database from the YDB endpoint section.
    • Endpoint from the Document API endpoint section.

    You'll need them in the next step.

Create a table in the database

  1. In the management console, select the folder containing the database.
  2. In the list of services, select Managed Service for YDB.
  3. Select the database.
  4. Go to the Navigation tab.
  5. In the top right-hand corner, click Create. Then, in the resulting menu, click Table.
  6. In the Name field, enter series. Fill in the remaining fields however you'd like.
  7. Click Create table.

Create a function

  1. Edit the main.env file:
    • FUNCTION_NAME: Function name.
    • folder_id: ID of the folder.
    • SERVICE_ACCOUNT_ID: Service account ID.
    • DOCUMENT_API_ENDPOINT: Value of the Endpoint field under Document API endpoint.
    • DATABASENAME: Value of the Database field under YDB endpoint.
    • ENTRYPOINT: String in the following format ://Endpoint field value under YDB endpoint>. For example, if the protocol is grpcs and the endpoint is ydb.serverless.yandexcloud.net:2135, enter grpcs://ydb.serverless.yandexcloud.net:2135.
    • YDB_SDK_LOGLEVEL: Logging level. Legal values: fatal, error, warn, info, debug, and trace.
  2. Create a function: 
    ./first-setup-func.sh
  3. Create the function version: 
    ./deploy.sh

Test the function

  1. In the management console, select the folder containing the function.

  2. In the list of services, select Cloud Functions.

  3. Select a function.

  4. Go to the Browse tab.

  5. Under General information, click on the call link.

  6. Once a successful connection to the database is established, the page will display a description of the series table fields in JSON format. For example:

    {
  "driver": true,
  "tableDef": {
    "info": "Describe table  series",
    "columns": [
      {
        "name": "series_id",
        "type": 4
      },
      {
        "name": "title",
        "type": 4608
      },
      {
        "name": "series_info",
        "type": 4608
      },
      {
        "name": "release_date",
        "type": 48
      }
    ]
  }
}
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