Adds code for snowflake container example running the UI (#1257)

* Adds code for snowflake container example running the UI

Note: this is a toy example. For real production needs, you'd need
to modify a few things:

1. not use SQLLITE, and instead postgresql, or implement django-snowflake connection.
2. likely not use the Hamilton code within the flask container, instead package up properly
and define a UDF or UDTF.
3. could use snowpark dataframes or have hamilton code do other things, e.g. LLM calls..

See https://medium.com/@pkantyka/observability-of-python-code-and-application-logic-with-hamilton-ui-on-snowflake-container-services-a26693b46635 for the write up.

docs/hamilton-ui/ui.rst

@@ -123,6 +123,12 @@ More extensive self-hosting documentation is in the works, e.g. Snowflake, Datab
 chart contribution!
 
 
+Running on Snowflake
+---------------------
+You can run the Hamilton UI on Snowflake Container Services. For a detailed guide, see the blog post
+`Observability of Python code and application logic with Hamilton UI on Snowflake Container Services <https://medium.com/@pkantyka/observability-of-python-code-and-application-logic-with-hamilton-ui-on-snowflake-container-services-a26693b46635>`_ by
+`Greg Kantyka <https://medium.com/@pkantyka>`_ and the `Hamilton Snowflake Example <https://github.com/DAGWorks-Inc/hamilton/tree/main/examples/snowflake/hamilton_ui>`_.
+
 -----------
 Get started
 -----------

examples/snowflake/hamilton_ui/Dockerfile

@@ -0,0 +1,14 @@
+FROM python:3.13.1-slim
+
+RUN apt update
+RUN apt upgrade sqlite3 -y
+RUN pip install "sf-hamilton[ui,sdk]"
+RUN pip install flask
+
+ENV HAMILTON_ALLOWED_HOSTS=".snowflakecomputing.app"
+ENV SERVER_PORT=8001
+
+COPY pipeline_endpoint.py /pipeline_endpoint.py
+COPY my_functions.py /my_functions.py
+
+ENTRYPOINT /bin/bash -c "(hamilton ui --base-dir /hamilton-basedir &) && python /pipeline_endpoint.py"

examples/snowflake/hamilton_ui/README.md

@@ -0,0 +1,16 @@
+# Running the Hamilton & the Hamilton UI in Snowflake
+
+This example is code for the ["Observability of Python code and application logic with Hamilton UI on Snowflake Container Services" post](https://medium.com/@pkantyka/observability-of-python-code-and-application-logic-with-hamilton-ui-on-snowflake-container-services-a26693b46635) by
+[Greg Kantyka](https://medium.com/@pkantyka).
+
+Here we show the code required to be packaged up for use on Snowflake:
+
+1. Docker file that runs the Hamilton UI and a flask endpoint to exercise Hamilton code
+2. my_functions.py - the Hamilton code that is exercised by the flask endpoint
+3. pipeline_endpoint.py - the flask endpoint that exercises the Hamilton code
+
+To run see:
+ - snowflake.sql that contains all the SQL to create the necessary objects in Snowflake and exercise things.
+
+For more details see ["Observability of Python code and application logic with Hamilton UI on Snowflake Container Services" post](https://medium.com/@pkantyka/observability-of-python-code-and-application-logic-with-hamilton-ui-on-snowflake-container-services-a26693b46635) by
+[Greg Kantyka](https://medium.com/@pkantyka).

examples/snowflake/hamilton_ui/my_functions.py

@@ -0,0 +1,21 @@
+import pandas as pd
+
+
+def spend_mean(spend: pd.Series) -> float:
+    """Shows function creating a scalar. In this case it computes the mean of the entire column."""
+    return spend.mean()
+
+
+def spend_zero_mean(spend: pd.Series, spend_mean: float) -> pd.Series:
+    """Shows function that takes a scalar. In this case to zero mean spend."""
+    return spend - spend_mean
+
+
+def spend_std_dev(spend: pd.Series) -> float:
+    """Function that computes the standard deviation of the spend column."""
+    return spend.std()
+
+
+def spend_zero_mean_unit_variance(spend_zero_mean: pd.Series, spend_std_dev: float) -> pd.Series:
+    """Function showing one way to make spend have zero mean and unit variance."""
+    return spend_zero_mean / spend_std_dev

examples/snowflake/hamilton_ui/pipeline_endpoint.py

@@ -0,0 +1,118 @@
+"""
+This module:
+- Defines a flask app that listens for POST requests on /echo
+- the /echo command is invoked from a Snowflake SQL query
+- the /echo command calls a function get_response that is defined in this module
+- get_response uses Hamilton to execute a pipeline defined in my_functions.py
+- my_functions.py contains the functions that are used in the pipeline
+- the pipeline is executed with the input data from the Snowflake query
+- the output of the pipeline is returned to Snowflake
+- the Hamilton UI tracker is used to track the execution of the pipeline
+"""
+
+import logging
+import os
+import sys
+
+import pandas as pd
+from flask import Flask, make_response, request
+
+from hamilton import registry
+
+registry.disable_autoload()
+import my_functions  # we import the module here!
+
+from hamilton import driver
+from hamilton_sdk import adapters
+
+# WRAPPER CODE FOR SNOWFLAKE FUNCTION ######
+
+SERVICE_HOST = os.getenv("SERVER_HOST", "0.0.0.0")
+SERVICE_PORT = os.getenv("SERVER_PORT", 8080)
+CHARACTER_NAME = os.getenv("CHARACTER_NAME", "I")
+
+
+def get_logger(logger_name):
+    logger = logging.getLogger(logger_name)
+    logger.setLevel(logging.DEBUG)
+    handler = logging.StreamHandler(sys.stdout)
+    handler.setLevel(logging.DEBUG)
+    handler.setFormatter(logging.Formatter("%(name)s [%(asctime)s] [%(levelname)s] %(message)s"))
+    logger.addHandler(handler)
+    return logger
+
+
+logger = get_logger("echo-service")
+
+app = Flask(__name__)
+
+
+@app.get("/healthcheck")
+def readiness_probe():
+    return "OK"
+
+
+@app.post("/echo")
+def echo():
+    """This is the endpoint that Snowflake will call to run Hamilton code."""
+    message = request.json
+    logger.debug(f"Received request: {message}")
+
+    if message is None or not message["data"]:
+        logger.info("Received empty message")
+        return {}
+
+    input_rows = message["data"]
+    logger.info(f"Received {len(input_rows)} rows")
+
+    output_rows = [[row[0], get_response(row[1], row[2], row[3], row[4])] for row in input_rows]
+    logger.info(f"Produced {len(output_rows)} rows")
+
+    response = make_response({"data": output_rows})
+    response.headers["Content-type"] = "application/json"
+    logger.debug(f"Sending response: {response.json}")
+    return response
+
+
+# END OF WRAPPER CODE FOR SNOWFLAKE FUNCTION ######
+
+
+def get_response(prj_id, spend, signups, output_columns):
+    """The function that is called from SQL on Snowflake."""
+    tracker = adapters.HamiltonTracker(
+        project_id=prj_id,
+        username="admin",
+        dag_name="MYDAG",
+        tags={"environment": "R&D", "team": "MY_TEAM", "version": "Beta"},
+    )
+    input_columns = {
+        "signups": pd.Series(spend),
+        "spend": pd.Series(signups),
+    }
+    dr = (
+        driver.Builder()
+        .with_config({})  # we don't have any configuration or invariant data for this example.
+        .with_modules(
+            my_functions
+        )  # we need to tell hamilton where to load function definitions from
+        .with_adapters(tracker)  # we add the Hamilton UI tracker
+        .build()
+    )
+
+    df = dr.execute(output_columns, inputs=input_columns)
+
+    serializable_df = {}
+
+    for key, value in df.items():
+        if isinstance(value, pd.Series):
+            # Convert Series to dict (or .tolist() for just values)
+            serializable_df[key] = {str(k): v for k, v in value.to_dict().items()}
+        else:
+            # Pass other values as is
+            serializable_df[key] = value
+
+    return serializable_df
+
+
+if __name__ == "__main__":
+    app.run(host=SERVICE_HOST, port=SERVICE_PORT)

examples/snowflake/hamilton_ui/requirements.txt

@@ -0,0 +1,2 @@
+flask
+sf-hamilton[ui,sdk]

examples/snowflake/hamilton_ui/snowflake.sql

@@ -0,0 +1,94 @@
+-- For more details visit:
+-- https://medium.com/@pkantyka/observability-of-python-code-and-application-logic-with-hamilton-ui-on-snowflake-container-services-a26693b46635
+
+CREATE SERVICE public.hamilton_ui
+IN COMPUTE POOL TEST_POOL
+FROM SPECIFICATION $$
+spec:
+  containers:
+  - name: hamiltonui
+    image: <account-url-registry-host>/<db-name>/<schema-name>/<repo-name>/snowflake-hamilton-ui
+    volumeMounts:
+    - name: hamilton-basedir
+      mountPath: /hamilton-basedir
+  endpoints:
+   - name: entrypoint
+     port: 8001
+   - name: hamilton
+     port: 8241
+     public: true
+  volumes:
+   - name: hamilton-basedir
+     source: "@<db-name>.<schema-name>.hamilton_base"
+  $$
+QUERY_WAREHOUSE = <warehause-name>
+;
+
+CALL SYSTEM$GET_SERVICE_STATUS('<db-name>.<schema>.hamilton_ui');
+
+CALL SYSTEM$GET_SERVICE_LOGS('<db-name>.<schema>.hamilton_ui', '0', 'hammiltonui', 1000);
+
+SHOW ENDPOINTS IN SERVICE public.hamilton_ui;
+
+CREATE OR REPLACE FUNCTION public.hamilton_pipeline (prj_id number, signups variant, spend variant, output_columns variant)
+  RETURNS VARIANT
+  SERVICE=public.hamilton_ui
+  ENDPOINT=entrypoint
+  AS '/echo';
+
+
+SELECT
+  public.hamilton_pipeline (
+    1,
+    [1, 10, 50, 100, 200, 400],
+    [10, 10, 20, 40, 40, 50],
+    [ 'spend', 'signups', 'spend_std_dev', 'spend_zero_mean_unit_variance' ]
+  ) as data;
+
+WITH input_data AS (
+  SELECT
+      public.hamilton_pipeline (
+        1,
+        [1, 10, 50, 100, 200, 400],
+        [10, 10, 20, 40, 40, 50],
+        [ 'spend', 'signups', 'spend_std_dev', 'spend_zero_mean_unit_variance' ]
+      ) as data
+),
+flattened AS (
+  SELECT
+    key AS metric_key,
+    value AS metric_value
+  FROM
+    input_data
+    left join LATERAL FLATTEN(input_data.data)
+)
+SELECT
+  *
+FROM
+  flattened f;
+
+WITH input_data AS (
+  SELECT
+      public.hamilton_pipeline (
+        1,
+        [1, 10, 50, 100, 200, 400],
+        [10, 10, 20, 40, 40, 50],
+        [ 'spend', 'signups', 'spend_std_dev', 'spend_zero_mean_unit_variance' ]
+      ) as data
+),
+flattened AS (
+  SELECT
+    key AS metric_key,
+    value AS metric_value
+  FROM
+    input_data
+    left join LATERAL FLATTEN(input_data.data)
+)
+SELECT
+  f2.key,
+  f2.value
+FROM
+  flattened f
+  left join lateral flatten(metric_value) f2
+where
+  metric_key = 'spend_zero_mean_unit_variance';