Technologies Used

• AWS S3: Cloud storage for raw data files.
• Snowflake: Cloud-based data warehouse.
• DBT (Data Build Tool): For SQL-based data transformations and schema management.
• Apache Airflow: Workflow orchestration tool for task automation.
• Streamlit: Framework for building interactive web-based dashboards.

Setting Enviroment

Step 1: Clone the repository:

mkdir dbt-snowflake-project
git clone https://github.com/caio-moliveira/dbt-snowflake-project.git
cd dbt-snowflake-project 

Step 2: Set up Snowflake enviroment:

-- Switch to the ACCOUNTADMIN role to perform setup
USE ROLE ACCOUNTADMIN;

-- Step 1: Create the dbt_transform role 
CREATE OR REPLACE ROLE dbt_role;
GRANT ROLE dbt_role TO ROLE ACCOUNTADMIN;

-- Step 2: Create the warehouse
CREATE WAREHOUSE IF NOT EXISTS DBT_WH
  WITH WAREHOUSE_SIZE = 'X-SMALL'
  MAX_CLUSTER_COUNT = 3
  AUTO_SUSPEND = 300 -- Seconds
  COMMENT = 'This is a warehouse for development and testing';

-- Step 3: Create the dbt_user and assign it to the role
CREATE USER IF NOT EXISTS dbt_user
    PASSWORD = 'your-password' 
    LOGIN_NAME = 'dbt_user'
    MUST_CHANGE_PASSWORD = FALSE
    DEFAULT_WAREHOUSE = 'DBT_WH'
    DEFAULT_ROLE = 'dbt_role'
    COMMENT = 'dbt user for operations and data transformation';

GRANT ROLE dbt_role TO USER dbt_user;

-- Step 4: Create the database and schemas
CREATE OR REPLACE DATABASE DBT_PROJECT;
CREATE OR REPLACE SCHEMA DBT_PROJECT.DBT_STAGING;

-- Create a storage integration for S3
CREATE OR REPLACE STORAGE INTEGRATION s3_project_integration
  TYPE = EXTERNAL_STAGE
  STORAGE_PROVIDER = 'S3'
  ENABLED = TRUE 
  STORAGE_AWS_ROLE_ARN = 'arn:aws:iam::your-role'
  STORAGE_ALLOWED_LOCATIONS = ('s3://your-bucket-name/')
  COMMENT = 'Integration for S3 bucket with CSV files';

-- Describe the integration to confirm setup - You will need to take an ID to use when Setting the IAM Policies
DESC INTEGRATION s3_project_integration;

CREATE OR REPLACE FILE FORMAT DBT_PROJECT.FILE_FORMATS.my_csv_format
TYPE = 'CSV'
FIELD_OPTIONALLY_ENCLOSED_BY = '"'      
NULL_IF = ('NULL', 'N/A')           
FIELD_DELIMITER = ','
PARSE_HEADER = TRUE;

-- Recreate in the correct schema
CREATE OR REPLACE STAGE DBT_PROJECT.EXTERNAL_STAGES.s3_books_stage
  URL = 's3://your-bucket-name/'
  STORAGE_INTEGRATION = s3_project_integration
  FILE_FORMAT = DBT_PROJECT.FILE_FORMATS.my_csv_format;

Step 3: Set up SnowPipe:

CREATE OR REPLACE PIPE DBT_PROJECT.DBT_STAGING.snowpipe_books AUTO_INGEST=TRUE
AS
COPY INTO DBT_PROJECT.DBT_STAGING.stg_raw_books
FROM @DBT_PROJECT.EXTERNAL_STAGES.s3_books_stage
FILE_FORMAT = (FORMAT_NAME = 'DBT_PROJECT.FILE_FORMATS.my_csv_format')
match_by_column_name=case_insensitive;

Step 4: Set up IAM for Snowpipe:

(Setting Snowpipe)[https://docs.snowflake.com/en/user-guide/data-load-snowpipe-auto-s3]

Follow this documentation to set your bucket in order to automate the pipeline.

Step 5: Set Up Airflow Connections

Check if files like Dockerfile, requirements.txt, docker-compose-override.yml exists. if yes, you are ready to run:

Astro dev start

In the Airflow UI, configure the necessary connections to integrate AWS S3 and Snowflake.

AWS S3 Connection

1. Navigate to Admin > Connections in the Airflow UI.
2. Create a new connection with the following details:
   • Conn Id: aws_s3
   • Conn Type: Amazon Web Services
   • Access Key: Your AWS Access Key
   • Secret Key: Your AWS Secret Key

Snowflake Connection

1. Navigate to Admin > Connections in the Airflow UI.
2. Create a new connection with the following details:
   • Conn Id: snowflake_default
   • Conn Type: Snowflake
   • Account: Snowflake account identifier
   • Username: Your Snowflake username
   • Password: Your Snowflake password
   • Database: Your database name
   • Schema: Default schema (optional)

Step 6: Define Airflow DAG:

Write a DAG script in Python to monitor the S3 bucket and trigger transformations.

Key Components of the DAG

1. S3KeySensor
   • Detects new files in the specified S3 bucket.

# Task 1: S3KeySensor to wait for any .csv file in the S3 folder
s3_sensor = S3KeySensor(
    task_id="s3-sensor",
    bucket_name=S3_BUCKET,  # Your S3 bucket name
    bucket_key=S3_PREFIX,  # Wildcard to match any .csv file
    aws_conn_id="aws_default",  # AWS connection set up in Airflow
    wildcard_match=True,
    poke_interval=30,  # Check every 30 seconds
    timeout=60 * 60 * 6,  # Timeout after 6 hours
    dag=dag,
)

2. BashOperator
   • Executes the dbt run command to perform data transformations.

# Configure the ProfileConfig for dbt
profile_config = ProfileConfig(
    profile_name="dbt_snowflake",
    target_name="dev",
    profile_mapping=SnowflakeUserPasswordProfileMapping(
        conn_id="Snowflake",
        profile_args={
            "database": "dbt_project",
            "schema": "dbt",
            "warehouse": "dbt_wh",
        },
    ),
)

# Define Cosmos DbtDag
cosmos_dbt_dag = DbtDag(
    dag_id="cosmos_dbt_dag",
    project_config=ProjectConfig(dbt_project_path),
    operator_args={"install_deps": True},
    profile_config=profile_config,
    execution_config=ExecutionConfig(
        dbt_executable_path="/usr/local/bin/dbt",
    ),
)

Workflow Overview

1. Wait for a new file to be uploaded to the S3 bucket.
2. Trigger the DBT transformation process.

By setting up these connections and defining the DAG, Airflow will automate the ingestion and transformation steps of your data pipeline.

Features

• Automated ingestion of files from S3 to Snowflake.
• Transformation of data into organized schemas (Raw, Intermediate, Marts).
• Scheduled workflows using Airflow.
• Real-time data analysis via Streamlit dashboards.

Troubleshooting

• S3 Upload Errors: Ensure the bucket's permissions and triggers are correctly configured.
• Snowpipe Issues: Verify Snowflake stage and pipe setup.
• DBT Transformation Errors: Check SQL models and their dependencies.
• Streamlit Connection Problems: Confirm Snowflake credentials and network access.