Build a House Price Predictor with SAP AI Core

You need a Docker repository to store your AI code on the cloud in the form of Docker images. SAP AI core will fetch your code from this Docker repository. The image ensures that your code is bundled along with all of the dependencies, directory structure and drivers that are required when using GPU.

INFORMATION You may use your organization’s own Docker registry/repository. But please ensure that the repository is internet facing, not protected by a firewall.

Sign Up for a Docker account.

Click on the profile button (your profile name) and then select Account Settings.

Select Security from the navigation bar and click New Access Token.

Follow the guided steps, and then store the token that you receive in your local system.

SECURITY TIP: This access token means that SAP AI Core can access the specified Docker repository without you sharing you Docker credentials. It also means that you can revoke access by deleting the token, rather than having to change your credentials.

Download and Install Docker Desktop. You will need Docker Desktop to help you build Docker images of your AI code.

Run your Docker Desktop. You will observe “whale icon” on your tray when Docker Desktop is running.

Create a directory (folder) named hello-aicore-code.

Create a file main.py. Paste the following snippet in the file.

# Load Datasets
from sklearn import datasets
data_house = datasets.fetch_california_housing()
X = data_house['data']
y = data_house['target']
#
# Partition into Train and test dataset
from sklearn.model_selection import train_test_split
train_x, test_x, train_y, test_y = train_test_split(X, y, test_size=0.3)
#
# Init model
from sklearn.tree import DecisionTreeRegressor
clf = DecisionTreeRegressor()
#
# Train model
clf.fit(train_x, train_y)
#
# Test model
test_r2_score = clf.score(test_x, test_y)
# Output will be available in logs of SAP AI Core.
# Not the ideal way of storing /reporting metrics in SAP AI Core, but that is not the focus this tutorial
print(f"Test Data Score {test_r2_score}")

Create another file requirements.txt in the same directory. Here you will mention which python libraries are required to execute your code.

RECOMMENDED In production you should use the terminal command pip list --format freeze > requirements.txt to auto generate requirements.txt.

Paste the following snippet into requirements.txt.

scikit-learn

The code builds a model using the California Housing Dataset available in Scikit-Learn. Note that the code neither reads a datafile nor stores the model. We will cover both of these in a different tutorial.

In the same directory, create a file named Dockerfile with no extension. This file stores instructions for Docker to build an image. Your Docker image is a Linux distribution, therefore commands in this Dockerfile are similar to Linux commands with verbs for Docker as the suffix. Paste the following content exactly as it is, into the file:

# Specify which base layers (default dependencies) to use
# You may find more base layers at https://hub.docker.com/
FROM python:3.7
#
# Creates directory within your Docker image
RUN mkdir -p /app/src/
#
# Copies file from your Local system TO path in Docker image
COPY main.py /app/src/
COPY requirements.txt /app/src/
#
# Installs dependencies within you Docker image
RUN pip3 install -r /app/src/requirements.txt
#
# Enable permission to execute anything inside the folder app
RUN chgrp -R 65534 /app && \
    chmod -R 777 /app

You may notice that you did not specify the command to run the script main.py in the Dockerfile. This command will be written into the AI workflow and is covered later in this tutorial.

Open your terminal and navigate to your hello-aicore-code directory. You will use the terminal to build your Docker image.

Copy and edit the following command to build your docker image. The command follows the format docker build -t <DOCKER_REGISTRY>/<YOUR_DOCKER_USERNAME>/<IMAGE_NAME>:<TAG_NAME>. So for example, if you are using your organization’s registry which has the URL myteam.myorg, The command should be docker build -t myteam.myorg/yourusername/house-price:01 .

docker build -t docker.io/<YOUR_DOCKER_USERNAME>/house-price:01 .

If you have machine with Apple Silicon M1/M2/M3 Chip, use –platform linux/amd64

docker build --platform linux/amd64 -t docker.io/<YOUR_DOCKER_USERNAME>/house-price:01 .

INFORMATION In the command, -t indicates that there is a tag name, followed by a colon and version. The name is your descriptive string, and the version can be in any format, here house-price and 01, respectively. The . (dot) at the end instructs Docker to look for the filename Dockerfile in the present directory.

INFORMATION The platform information relates to your operating system, for example, linux/amd64. By default, Docker builds the image for your machine’s native architecture. If you are using an ARM-based system (such as an Apple M1/M2 or Raspberry Pi), the build process may default to arm64, which could cause issues when running the container on an amd64 cluster. To avoid such compatibility problems, explicitly specify the platform using the –platform linux/amd64 flag when building the image.

The result of this command should be:

Login to your Docker account from your terminal. This is a one time step that stores your Docker account credentials in your local Docker Desktop.

INFORMATION If you are using your organization docker registry (hosting) please use the command in the format docker login <URL_YOUR_ORGANIZATIONS_DOCKER_REGISTRY>

docker login docker.io

Copy and paste your generated Docker Access Token to use as your password. For security reasons, your input will not be printed on the screen.

docker push docker.io/<YOUR_USERNAME>/house-price:01

This step is required once. Storing Docker credentials enables SAP AI Core to pull (download) your Docker images from a private Docker repository. Use of a private Docker image prevents others from seeing your content.

WARNING SAP AI Core does not verify your docker credentials, please ensure that you are storing the correct credentials.

1. Name: Enter credstutorialrepo. This is becomes an identifier for your Docker credentials within SAP AI Core. This value is your docker registry secret.
2. URL: If you have used your organization’s Docker registry then use its URL, otherwise, enter https://index.docker.io.
3. Username: Your Docker username.
4. Access Token: The access token generated previously, in the Docker account settings.

TIP You can store multiple Docker credentials in SAP AI Core.

This step requires the GitHub folder that you synced in this tutorial. In this folder, create another YAML file called code-pipeline.yaml. (This filename is not used as an identifier within SAP AI Core.)

Paste the following snippet into your YAML file. Edit the highlighted lines, using the comments and your own Docker image information. Click Commit Changes. The code is also available by following this link

apiVersion: argoproj.io/v1alpha1
kind: WorkflowTemplate
metadata:
  name: code-pipeline # executable id, must be unique across all your workflows (YAML files), please modify this to any value (e.g. code-pipeline-12345) if you are not the only user of your SAP AI Core instance.
  annotations:
    scenarios.ai.sap.com/description: "Tutorial to add custom code to SAP AI Core"
    scenarios.ai.sap.com/name: "Code (Tutorial)"
    executables.ai.sap.com/description: "Trains model on median house prices"
    executables.ai.sap.com/name: "House Price (Sklearn Example)"
  labels:
    scenarios.ai.sap.com/id: "learning-code"
    ai.sap.com/version: "1.0"
spec:
  imagePullSecrets:
    - name: credstutorialrepo # your docker registry secret
  entrypoint: mypipeline
  templates:
  - name: mypipeline
    steps:
    - - name: mypredictor
        template: mycodeblock1

  - name: mycodeblock1
    container:
      image: docker.io/<YOUR_DOCKER_USERNAME>/house-price:01 # Your docker image name
      command: ["/bin/sh", "-c"]
      args:
        - "python /app/src/main.py"

Observe the difference between the hello.yaml (created in the prerequisite tutorial) and code-pipeline.yaml.

1. imagePullSecrets: A key that specifies which credentials will be used to access the Docker registry. The value credstutorialrepo specifies the Docker registry secret that you created previously to store Docker information in SAP AI Core.
2. image: A key that specifies which code to use in the workflow and which commands to execute within the Docker image.

How is a different Scenario created even when the application is syncing the your GitHub folder?

The application’s only task is to sync and look for syntax errors in YAML files. By modifying annotations (scenarios.ai.sap.com/id, scenarios.ai.sap.com/name and scenarios.ai.sap.com/description) within the YAML you create new scenario.

The execution will go from UNKNOWN to RUNNING then to the DEAD state. Resolving this is covered in next step.

We can see that scikit-learn was unable to create directory for caching. Let’s resolve this in the next step.

Update the highlighted line in main.py. Set the parameter data_home of function dataset.fetch_california_housing to /app/src. You had already set elevated permissions for this directory in your Dockerfile.

Build your code again, this time with a new tag. We use 02, i.e. the second version of your Docker image.

docker build -t docker.io/<YOUR_DOCKER_USERNAME>/house-price:02 .

Upload your code to your Docker registry.

docker push docker.io/<YOUR_DOCKER_USERNAME>/house-price:02

Locate your workflow (YAML file) in GitHub. Click on the Pencil Icon to edit your workflow. The original code is also available by following this link

Update your workflow by adding the new 02 tag to the ai.sap.com/version and the Docker image name.

Click Commit Changes after editing.

Why update the version each time you make changes to your workflow?

The executable version is denoted by ai.sap.com/version. SAP AI Core syncs you workflows every three minutes and the version number is easily observable. You can be confident that your changes have synced. An alternative method of checking is to check that the latest REVISION number from GitHub is reflected in AI Core.

AI core Also provides the functionality to auto schedule Executions based on Time.

To schedule an Execution at particular time of the day visit ML operations > schedules and click on Add

Choose scenario as House price and click on next

Choose Executable and click on next.

Now a screen will appear where you can choose between the available Execution config and click on next

Now we need to choose the Schedule for our execution. Enter name as Demo-Schedule and choose between date and time in case you need to run the Execution for once else Choose recurring Enter the cron Job and choose the start and end date and click on Review

Check all the details before creating the execution and click on Create.

You would be able to see the schedule created under schedules tab in ML operations