Snowflake (via Collector method)

About Collectors

Pre-requisites

• Python 3.6 - 3.9

• Access to the KADA Collector repository that contains the Snowflake whl

  • The repository is currently hosted in KADA’s Azure Blob Storage. You will be given a SAS token to access the repository. Reach out to KADA Support (support@kada.ai) if you do not have access.

  • Download the Snowflake whl (e.g. kada_collectors_extractors_snowflake-#.#.#-py3-none-any.whl)

• Access to Snowflake (see section below)

• Access to K landing directory

Snowflake Access

Create a Snowflake user with read access to following tables in the Snowflake database.

• account_usage.history

• account_usage.views

• account_usage.tables

• account_usage.columns

• account_usage.copy_history

• account_usage.grants_to_roles

• account_usage.grants_to_users

You can use the following code:

Log in with a user that has the permissions to create a role/user

--Create a new role for the Catalog user
Create role CATALOG_READ_ONLY;

--Grant the role access to the Accoutn usage schema
grant select on all tables in schema SNOWFLAKE.ACCOUNT_USAGE to CATALOG_READ_ONLY;

--Create a new user for K and grant it the role (remove the [])
create user [kada_user] password=['abc123!@#'] default_role = CATALOG_READ_ONLY default_warehouse = [warehouse];

From the above record down the following to be used for the setup

1. User name / Password

2. Role

3. Warehouse

4. Snowflake account (found in the URL of your Snowflake instance - between https:// and .snowflakecomputing.com/…)

Snowflake integration uses username/password. Using keys will be supported in an upcoming release

Step 1: Create the Source in K

Create a Snowflake source in K

• Go to Settings, Select Sources and click Add Source

• Select “Load from File” option
  

  

• Give the source a Name - e.g. Snowflake Production

• Add the Host name for the Snowflake Server

• Click Finish Setup

Step 2: Getting Access to the Source Landing Directory

Step 3: Install the Collector

It is recommended to use a python environment such as pyenv or pipenv if you are not intending to install this package at the system level.

Some python packages also have dependencies on the OS level packages, so you may be required to install additional OS packages if the below fails to install.

Run the following command to install the collector

pip install kada_collectors_extractors_snowflake-#.#.#-py3-none-any.whl

These are some known possible packages you may require depending on your OS, this is not exhaustive and only serves as a guide.

Step 4: Configure the Collector

The collector requires a set of parameters to connect to and extract metadata from Snowflake

These parameters can be added directly into the run or you can use pass the parameters in via a JSON file. The following is an example you can use that is included in the example run code below.

kada_snowflake_extractor_config.json

{
    "account": "",
    "username": "",
    "password": "",
    "information_database": "",
    "role": "",
    "warehouse": "",
    "databases": [],
    "login_timeout": 5,
    "output_path": "/tmp/output",
    "mask": true
}

Step 5: Run the Collector

The following code is an example of how to run the extractor. You may need to uplift this code to meet any code standards at your organisation.

This can be executed in any python environment where the whl has been installed.

This code sample uses the kada_snowflake_extractor_config.json for handling the configuration details

import os
import argparse
from kada_collectors.extractors.utils import load_config, get_hwm, publish_hwm, get_generic_logger
from kada_collectors.extractors.snowflake import Extractor

get_generic_logger('root') # Set to use the root logger, you can change the context accordingly or define your own logger

_type = 'snowflake'
dirname = os.path.dirname(__file__)
filename = os.path.join(dirname, 'kada_{}_extractor_config.json'.format(_type))

parser = argparse.ArgumentParser(description='KADA Snowflake Extractor.')
parser.add_argument('--config', '-c', dest='config', default=filename, help='Location of the configuration json, default is the config json in the same directory as the script.')
args = parser.parse_args()

start_hwm, end_hwm = get_hwm(_type)

ext = Extractor(**load_config(args.config))
ext.test_connection()
ext.run(**{"start_hwm": start_hwm, "end_hwm": end_hwm})

publish_hwm(_type, end_hwm)

Advance options:

If you wish to maintain your own high water mark files elsewhere you can use the above section’s script as a guide on how to call the extractor. The configuration file is simply the keyword arguments in JSON format. Refer to this document for more information https://kadaai.atlassian.net/wiki/spaces/KSL/pages/1902411777/Additional+Notes#Storing-HWM-in-another-location

If you are handling external arguments of the runner yourself, you’ll need to consider additional items for the run method. Refer to this document for more information https://kadaai.atlassian.net/wiki/spaces/KSL/pages/1902411777/Additional+Notes#The-run-method

Step 6: Check the Collector Outputs

K Extracts

A set of files (eg metadata, databaselog, linkages, events etc) will be generated. These files will appear in the output_path directory you set in the configuration details

High Water Mark File

A high water mark file is created in the same directory as the execution called snowflake_hwm.txt and produce files according to the configuration JSON. This file is only produced if you call the publish_hwm method.

Step 7: Push the Extracts to K

Once the files have been validated, you can push the files to the K landing directory.

You can use Azure Storage Explorer if you want to initially do this manually. You can push the files using python as well (see Airflow example below)

Example: Using Airflow to orchestrate the Extract and Push to K