GuidesRecipesAPI ReferenceChangelogDiscussions
Log In


Chassisml Version Update Warning

Note: this guide only works when using Chassisml version 1.4.13 or lower. Please visit the latest framework examples here.

This guide demonstrates the process of automatically containerizing your PMML model.


What you will need

  • Dockerhub account
  • Connection to running service (either from a local deployment or via publicly-hosted service)
  • Trained PMML model that can be loaded into memory or code to train a PMML model from scratch
  • Python environment

NOTE: To follow along, you can reference the Jupyter notebook example and data files here.

Set Up Environment


We recommend you follow this guide using a Jupyter Notebook. Follow the appropriate install instructions based on your environment.

Create a Python virtual environment and install the python packages required to load and run your model. At a minimum, pip install the following packages:

pip install chassisml modzy-sdk

If you would like to follow this guide directly, pip install the following additional packages:


Load Model into Memory

If you plan to use the Chassis service, you must first load your model into memory. If you have your trained model file saved locally (.pth, .pkl, .h5, .joblib, or other file format), you can load your model from the weights file directly, or alternatively train and use the model object.

import chassisml
import numpy as np
import json
from io import StringIO
from sklearn.datasets import load_iris
from sklearn.model_selection import train_test_split
import pandas as pd
import numpy as np
from sklearn_pmml_model.ensemble import PMMLForestClassifier

# Prepare data
iris = load_iris()
X = pd.DataFrame(
X.columns = np.array(iris.feature_names)
y = pd.Series(np.array(iris.target_names)[]) = "Class"
Xtr, Xte, ytr, yte = train_test_split(X, y, test_size=0.33, random_state=123)

# Create sample data for testing later
with open("data/sample_iris.csv", "w") as f:
    Xte[:10].to_csv(f, index=False)

# Load model
clf = PMMLForestClassifier(pmml="models/randomForest.pmml")
labels = clf.classes_.tolist()

# Test model
clf.score(Xte, yte)

def preprocess_inputs(raw_input_bytes):
    # load data
    inputs = pd.read_csv(StringIO(str(raw_input_bytes, "utf-8")))
    return inputs

def postprocess_outputs(raw_predictions):
    # process output
    inference_result = {
                "row": i+1,
                "classPredictions": [
                    {"class": labels[idx], "score": results[idx]}
                    for idx in np.argsort(results)[::-1]
            } for i, results in enumerate(raw_predictions)


    # format output
    structured_output = {
        "data": {
            "result": inference_result["result"],
            "explanation": None,
            "drift": None,

    return structured_output

Define process Function

You can think of this function as your "inference" function that will take input data as raw bytes, process the inputs, make predictions, and return the results. This method is the sole parameter required to create a ChassisModel object.

def process(input_bytes):
    # load data
    inputs = preprocess_inputs(input_bytes)
    # make predictions
    output = clf.predict_proba(inputs)
    # process output
    structured_output = postprocess_outputs(output)
    return structured_output

Create ChassisModel Object and Publish Model

First, connect to a running instance of the Chassis service - either by deploying on your machine or by connecting to the publicly hosted version of the service). Then, you can use the process function you defined to create a ChassisModel object, run a few tests to ensure your model object returns the expected results, and finally publish your model.

chassis_client = chassisml.ChassisClient("http://localhost:5000")
chassis_model = chassis_client.create_model(process_fn=process)

Define sample file from local filepath and run a series of tests.

NOTE: test_env method is not available on publicly-hosted service.

sample_filepath = './data/sample_iris.csv'
results = chassis_model.test(sample_filepath)

test_env_result = chassis_model.test_env(sample_filepath)

Define your Dockerhub credentials and publish your model.

dockerhub_user = <my.username>
dockerhub_pass = <my.password>
modzy_url = <modzy.base.url> # E.g.,
modzy_api_key = <my.modzy.api.key> # E.g., 8eba4z0AHqguxyf1gU6S.4AmeDQYIQZ724AQAGLJ8

response = chassis_model.publish(
   model_name="PMML Random Forest Iris Classification",

job_id = response.get('job_id')
final_status = chassis_client.block_until_complete(job_id)

You have successfully completed the packaging of your ONNX model. In your Dockerhub account, you should see your new container listed in the "Repositories" tab.


Figure 1. Example Chassis-built Container

Congratulations! In just minutes you automatically created a Docker container with just a few lines of code. To deploy your new model container to Modzy, follow one of the following guides:

What’s Next