Quickstart

Get started with LocalStack for Snowflake in a few simple steps

  3 minute read  

Introduction

This guide explains how to set up the Snowflake emulator and develop a Python program using the Snowflake Connector for Python (snowflake-connector-python) to interact with emulated Snowflake running on your local machine.

Prerequisites

Instructions

Before you begin, pull the Snowflake emulator image (localstack/snowflake) and start the container:

$ export LOCALSTACK_AUTH_TOKEN=<your_auth_token>
$ IMAGE_NAME=localstack/snowflake:latest localstack start

Check the emulator’s availability by running:

$ curl -d '{}' snowflake.localhost.localstack.cloud:4566/session


{"success": true}

Connect to the Snowflake emulator

Create a new Python file named main.py and use the following code to connect to the Snowflake emulator:

import snowflake.connector as sf

sf_conn_obj = sf.connect(
    user="test",
    password="test",
    account="test",
    database="test",
    host="snowflake.localhost.localstack.cloud",
)

Specify the host parameter as snowflake.localhost.localstack.cloud and the other parameters as test to avoid connecting to the real Snowflake instance.

Create and execute a query

Extend the Python program to insert rows from a list object into the emulated Snowflake table. Create a cursor object and execute the query:

print("1. Insert lot of rows from a list object to Snowflake table")
print("2. Creating a cursor object")
sf_cur_obj = sf_conn_obj.cursor()

print("3. Executing a query on cursor object")
try:
    sf_cur_obj.execute(
        "create or replace table "
        "ability(name string, skill string )")

    rows_to_insert = [('John', 'SQL'), ('Alex', 'Java'), ('Pete', 'Snowflake')]
    
    sf_cur_obj.executemany(
        " insert into ability (name, skill) values (%s,%s) " ,rows_to_insert)

    sf_cur_obj.execute("select name, skill from ability")

    print("4. Fetching the results")
    result = sf_cur_obj.fetchall()
    print("Total # of rows :" , len(result))
    print("Row-1 =>",result[0])
    print("Row-2 =>",result[1])
finally:
    sf_cur_obj.close()

This program creates a table named ability, inserts rows, and fetches the results.

Run the Python program

Execute the Python program with:

$ python main.py

The output should be:

Insert lot of rows from a list object to Snowflake table
1. Insert lot of rows from a list object to Snowflake table
2. Creating a cursor object
3. Executing a query on cursor object
4. Fetching the results
Total # of rows : 3
Row-1 => ('John', 'SQL')
Row-2 => ('Alex', 'Java')

Verify the results by navigating to the LocalStack logs:

2024-02-22T06:03:13.627  INFO --- [   asgi_gw_0] localstack.request.http    : POST /session/v1/login-request => 200
2024-02-22T06:03:16.122  WARN --- [   asgi_gw_0] l.packages.core            : postgresql will be installed as an OS package, even though install target is _not_ set to be static.
2024-02-22T06:03:45.917  INFO --- [   asgi_gw_0] localstack.request.http    : POST /queries/v1/query-request => 200
2024-02-22T06:03:46.016  INFO --- [   asgi_gw_1] localstack.request.http    : POST /queries/v1/query-request => 200
2024-02-22T06:03:49.361  INFO --- [   asgi_gw_0] localstack.request.http    : POST /queries/v1/query-request => 200
2024-02-22T06:03:49.412  INFO --- [   asgi_gw_1] localstack.request.http    : POST /session => 200

Destroy the local infrastructure

To stop LocalStack and remove locally created resources, use:

$ localstack stop

LocalStack is ephemeral and doesn’t persist data across restarts. It runs inside a Docker container, and once it’s stopped, all locally created resources are automatically removed. In a future release of the Snowflake emulator, we will provide proper persistence and integration with our Cloud Pods feature as well.

Next steps

You can now explore the following resources to learn more about the Snowflake emulator:

  • User Guide: Learn about the Snowflake emulator’s features and how to use them.
  • Tutorials: Explore tutorials to use the Snowflake emulator for local development and testing.
  • References: Find information about the Snowflake emulator’s configuration, changelog, and function coverage.