Part 1: Creating a Databricks Job to Run a Notebook

1: Create the Notebook in Databricks

  1. Open your Databricks workspace.
  2. Navigate to the Workspace section and click CreateNotebook.
  3. Give the notebook a name (e.g., sample_Notebook) and select the language (Python, Scala, SQL, etc.).
  4. Write your code in the notebook

2: Create a Databricks Job to Trigger the Notebook

  1. Go to Jobs in the Databricks workspace.

  2. Click Create Job.

  3. Provide the Job name (e.g., Sample_Job).

  4. Under Tasks, click Add task:

    • Task name: Notebook Task
    • Type: Notebook
    • Notebook path: Select the notebook you created (e.g., /Workspace/Users/your-notebook).
    • Optional: Add parameters if required by the notebook.
    • Choose the appropriate cluster configuration to run your notebook.
  5. Click Create to save the job.

  6. Note the Job ID. You will need this to trigger the job from the Infoworks Bash node.



Part 2: Triggering the Databricks Job from Infoworks Bash Node

Step 1: Authentication Using Azure Service Principal

Databricks requires authentication to trigger jobs via API. We will use Azure Service Principal credentials for this purpose.

Ensure you have the following:

  • client_id: Application ID of your Azure Service Principal.
  • tenant_id: Azure tenant ID.
  • client_secret: Azure client secret. Note: Please store the client secret in Azure Key Vault and create the secret name on Infoworks to use the 'client_secret' securely in bash node. 
  • Databricks workspace URL: E.g., https://<region>.azuredatabricks.net.
  • Job ID: From the Databricks job created in Part 1.

Step 2: Create Infoworks Bash Node to Trigger the Job and Handle Authentication


Copy the below bash script to Infoworks Bash Node. The script will, 

  1. Authenticate with Azure.
  2. Trigger the Databricks Job.
  3. Poll for the job status until it completes.
  4. Handle token expiry if needed.



#!/bin/bash

# Set Azure and Databricks variables from parameters
client_id="{{ params.runtime.client_id }}"
tenant_id="{{ params.runtime.tenant_id }}"
client_secret="$secret_val" # Replace with env variable mapped to the secret name
databricks_url="{{ params.runtime.databricks_url }}"
job_id="{{ params.runtime.job_id }}"
poll_interval=30  # Poll job status every 30 seconds
    

# Function to authenticate and obtain a new access token
function get_access_token() {
    echo "Authenticating with Azure..."
    token_response=$(curl -s -X POST \
      -d "grant_type=client_credentials" \
      -d "client_id=${client_id}" \
      -d "client_secret=${client_secret}" \
      "https://login.microsoftonline.com/${tenant_id}/oauth2/token")

    # Extract the access token
    access_token=$(echo "$token_response" | jq -r '.access_token')

    if [[ -z "$access_token" || "$access_token" == "null" ]]; then
        echo "Error: Failed to obtain access token."
        echo "Response: $token_response"
        exit 1
    fi

    echo "Successfully authenticated with Azure."
}

# Function to check job status
function check_job_status() {
    local run_id="$1"
    status_response=$(curl -s -X GET "${databricks_url}/api/2.1/jobs/runs/get?run_id=${run_id}" \
        -H "Authorization: Bearer ${access_token}")

    # Check if the API request was successful
    if [[ $? -ne 0 ]]; then
        echo "Error: Failed to get job status. Refreshing token..."
        get_access_token
        return 1
    fi

    echo "$status_response"
}

# Authenticate initially to get the access token
get_access_token

# Trigger the Databricks job
echo "Triggering Databricks job (ID: $job_id)..."
trigger_response=$(curl -s -X POST "${databricks_url}/api/2.1/jobs/run-now" \
    -H "Authorization: Bearer ${access_token}" \
    -H "Content-Type: application/json" \
    -d "{\"job_id\": ${job_id}}")

# Extract run ID and check for errors
run_id=$(echo "$trigger_response" | jq -r '.run_id')

if [[ -z "$run_id" || "$run_id" == "null" ]]; then
    echo "Error: Failed to trigger job."
    echo "Response: $trigger_response"
    exit 1
fi

echo "Job triggered successfully. Run ID: $run_id"

# Poll for the job status until it completes
while true; do
    echo "Checking job status..."
    job_status_response=$(check_job_status "$run_id")

    # Check if the job status API call was successful
    if [[ $? -ne 0 ]]; then
        # Retry fetching job status if the access token was refreshed
        job_status_response=$(check_job_status "$run_id")
    fi

    # Extract the job state and result state
    life_cycle_state=$(echo "$job_status_response" | jq -r '.state.life_cycle_state')
    result_state=$(echo "$job_status_response" | jq -r '.state.result_state')

    echo "Job is in state: $life_cycle_state"

    # Check if the job is completed
    if [[ "$life_cycle_state" == "TERMINATED" ]]; then
        if [[ "$result_state" == "SUCCESS" ]]; then
            echo "Job completed successfully!"
            echo "Job URL: $databricks_url/jobs/$job_id/runs/$run_id"
            exit 0
        else
            echo "Job failed or was cancelled. Result state: $result_state"
             echo "Job URL: $databricks_url/jobs/$job_id/runs/$run_id"
            exit 1
        fi
    elif [[ "$result_state" == "FAILED" || "$result_state" == "CANCELED" ]]; then
        echo "Job failed with result state: $result_state"
        echo "Job URL: $databricks_url/jobs/$job_id/runs/$run_id"
        exit 1
    fi

    # Sleep for the polling interval before checking again
    echo "Job is still running. Checking again in ${poll_interval} seconds..."
    sleep $poll_interval
done


Create Workflow Parameters for below,


1. client_id

2. tenant_id

3.databricks_url

4.job_id


Replace secret_val within the bash script on  with the  env variable name mapped to 'secret name' 

client_secret="$secret_val"



Hit Save and Run the workflow.