Collect Nucleus Asset Metadata logs

Supported in:

Google secops SIEM

This document explains how to ingest Nucleus Security asset metadata logs to Google Security Operations using Google Cloud Storage V2.

Nucleus Security is a vulnerability management platform that aggregates and prioritizes asset metadata from multiple scanners, providing a unified view of your organization's security posture. The parser extracts fields from Nucleus asset data and maps them to the Unified Data Model (UDM), capturing asset identity, IP addresses, hostnames, and vulnerability scores.

Before you begin

Make sure that you have the following prerequisites:

A Google SecOps instance
A GCP project with Cloud Storage API enabled
Permissions to create and manage GCS buckets
Permissions to manage IAM policies on GCS buckets
Permissions to create Cloud Run services, Pub/Sub topics, and Cloud Scheduler jobs
Privileged access to Nucleus Security with administrator permissions and API key access

Create Google Cloud Storage bucket

Go to the Google Cloud Console.
Select your project or create a new one.
In the navigation menu, go to Cloud Storage > Buckets.
Click Create bucket.

Provide the following configuration details:

Setting	Value
Name your bucket	Enter a globally unique name (for example, `nucleus-asset-logs`)
Location type	Choose based on your needs (Region, Dual-region, Multi-region)
Location	Select the location (for example, `us-central1`)
Storage class	Standard (recommended for frequently accessed logs)
Access control	Uniform (recommended)
Protection tools	Optional: Enable object versioning or retention policy

Click Create.

Collect Nucleus Security API credentials

Generate an API key

Sign in to the Nucleus Security platform with administrator credentials.
Go to Settings > API Keys.
Click Generate API Key.
Enter a label for the key (for example, Google Security Operations Integration).
Copy and securely store the API key.

Note: The API key provides read access to all projects and assets in your Nucleus Security account. Store it securely and do not share it.

Identify your project ID

Sign in to the Nucleus Security platform.
Navigate to Projects.
Click on the project you want to collect asset data from.
Note the Project ID from the URL or project settings page.

Verify permissions

To verify the API key has the required permissions:

Sign in to the Nucleus Security platform.
Go to Settings > API Keys.
Confirm the API key you generated is listed and has an Active status.
Verify the key has read access to the target project.

Test API access

Test your credentials before proceeding with the integration:

# Replace with your actual credentials
API_KEY="<your-api-key>"
PROJECT_ID="<your-project-id>"

# Test API access - list assets
curl -v -H "x-apikey: ${API_KEY}" \
  "https://app.nucleussec.com/nucleus/api/v1/projects/${PROJECT_ID}/assets?start=0&limit=10"

Create service account for Cloud Run function

The Cloud Run function needs a service account with permissions to write to GCS bucket and be invoked by Pub/Sub.

Create service account

In the GCP Console, go to IAM & Admin > Service Accounts.
Click Create Service Account.
Provide the following configuration details:
- Service account name: Enter nucleus-asset-collector-sa
- Service account description: Enter Service account for Cloud Run function to collect Nucleus Security asset metadata logs
Click Create and Continue.
In the Grant this service account access to project section, add the following roles:
1. Click Select a role.
2. Search for and select Storage Object Admin.
3. Click + Add another role.
4. Search for and select Cloud Run Invoker.
5. Click + Add another role.
6. Search for and select Cloud Functions Invoker.
Click Continue.
Click Done.

These roles are required for:

Storage Object Admin: Write logs to GCS bucket and manage state files
Cloud Run Invoker: Allow Pub/Sub to invoke the function
Cloud Functions Invoker: Allow function invocation

Grant IAM permissions on GCS bucket

Grant the service account write permissions on the GCS bucket:

Go to Cloud Storage > Buckets.
Click on your bucket name (for example, nucleus-asset-logs).
Go to the Permissions tab.
Click Grant access.
Provide the following configuration details:
- Add principals: Enter the service account email (for example, nucleus-asset-collector-sa@PROJECT_ID.iam.gserviceaccount.com)
- Assign roles: Select Storage Object Admin
Click Save.

Create Pub/Sub topic

Create a Pub/Sub topic that Cloud Scheduler will publish to and the Cloud Run function will subscribe to.

In the GCP Console, go to Pub/Sub > Topics.
Click Create topic.
Provide the following configuration details:
- Topic ID: Enter nucleus-asset-trigger
- Leave other settings as default
Click Create.

Create Cloud Run function to collect logs

The Cloud Run function will be triggered by Pub/Sub messages from Cloud Scheduler to fetch asset metadata from the Nucleus Security API and write it to GCS.

In the GCP Console, go to Cloud Run.
Click Create service.
Select Function (use an inline editor to create a function).
In the Configure section, provide the following configuration details:

Setting Value

Service name nucleus-asset-collector

Region Select region matching your GCS bucket (for example, us-central1)

Runtime Select Python 3.12 or later
In the Trigger (optional) section:
1. Click + Add trigger.
2. Select Cloud Pub/Sub.
3. In Select a Cloud Pub/Sub topic, choose the Pub/Sub topic (nucleus-asset-trigger).
4. Click Save.
In the Authentication section:
1. Select Require authentication.
2. Check Identity and Access Management (IAM).
Note: Pub/Sub will automatically handle authentication when invoking the function.
Scroll down and expand Containers, Networking, Security.
Go to the Security tab:
- Service account: Select the service account (nucleus-asset-collector-sa)

Setting	Value
Service name	`nucleus-asset-collector`
Region	Select region matching your GCS bucket (for example, `us-central1`)
Runtime	Select Python 3.12 or later

Go to the Containers tab:

Click Variables & Secrets.
Click + Add variable for each environment variable:

Variable Name	Example Value	Description
`GCS_BUCKET`	`nucleus-asset-logs`	GCS bucket name
`GCS_PREFIX`	`nucleus-assets`	Prefix for log files
`STATE_KEY`	`nucleus-assets/state.json`	State file path
`API_KEY`	`your-api-key`	Nucleus Security API key
`PROJECT_ID`	`your-project-id`	Nucleus Security project ID
`MAX_RECORDS`	`5000`	Max records per run
`PAGE_SIZE`	`1000`	Records per page (max 1000)

In the Variables & Secrets section, scroll down to Requests:
- Request timeout: Enter 600 seconds (10 minutes)
Go to the Settings tab:
- In the Resources section:
  - Memory: Select 512 MiB or higher
  - CPU: Select 1
In the Revision scaling section:
- Minimum number of instances: Enter 0
- Maximum number of instances: Enter 100 (or adjust based on expected load)
Click Create.
Wait for the service to be created (1-2 minutes).
After the service is created, the inline code editor will open automatically.

Add function code

Enter main in the Entry point field.

In the inline code editor, create two files:

main.py:

import functions_framework
from google.cloud import storage
import json
import os
import urllib3
from datetime import datetime, timezone, timedelta
import time

# Initialize HTTP client with timeouts
http = urllib3.PoolManager(
  timeout=urllib3.Timeout(connect=5.0, read=30.0),
  retries=False,
)

# Initialize Storage client
storage_client = storage.Client()

# Environment variables
GCS_BUCKET = os.environ.get('GCS_BUCKET')
GCS_PREFIX = os.environ.get('GCS_PREFIX', 'nucleus-assets')
STATE_KEY = os.environ.get('STATE_KEY', 'nucleus-assets/state.json')
API_KEY = os.environ.get('API_KEY')
PROJECT_ID = os.environ.get('PROJECT_ID')
MAX_RECORDS = int(os.environ.get('MAX_RECORDS', '5000'))
PAGE_SIZE = int(os.environ.get('PAGE_SIZE', '1000'))

@functions_framework.cloud_event
def main(cloud_event):
  """
  Cloud Run function triggered by Pub/Sub to fetch Nucleus Security
  asset metadata and write to GCS.

  Args:
    cloud_event: CloudEvent object containing Pub/Sub message
  """

  if not all([GCS_BUCKET, API_KEY, PROJECT_ID]):
    print('Error: Missing required environment variables')
    return

  try:
    # Get GCS bucket
    bucket = storage_client.bucket(GCS_BUCKET)

    # Load state
    state = load_state(bucket, STATE_KEY)

    now = datetime.now(timezone.utc)
    print(f"Starting asset metadata collection at {now.isoformat()}")

    # Fetch assets
    records, total = fetch_assets(
      api_key=API_KEY,
      project_id=PROJECT_ID,
      page_size=PAGE_SIZE,
      max_records=MAX_RECORDS,
    )

    if not records:
      print("No asset records found.")
      save_state(bucket, STATE_KEY, now.isoformat())
      return

    # Write to GCS as NDJSON
    timestamp = now.strftime('%Y%m%d_%H%M%S')
    object_key = f"{GCS_PREFIX}/assets_{timestamp}.ndjson"
    blob = bucket.blob(object_key)

    ndjson = '\n'.join([json.dumps(record, ensure_ascii=False) for record in records]) + '\n'
    blob.upload_from_string(ndjson, content_type='application/x-ndjson')

    print(f"Wrote {len(records)} records to gs://{GCS_BUCKET}/{object_key}")

    # Update state
    save_state(bucket, STATE_KEY, now.isoformat())

    print(f"Successfully processed {len(records)} asset records")

  except Exception as e:
    print(f'Error processing logs: {str(e)}')
    raise

def load_state(bucket, key):
  """Load state from GCS."""
  try:
    blob = bucket.blob(key)
    if blob.exists():
      state_data = blob.download_as_text()
      return json.loads(state_data)
  except Exception as e:
    print(f"Warning: Could not load state: {e}")

  return {}

def save_state(bucket, key, last_event_time_iso: str):
  """Save the last event timestamp to GCS state file."""
  try:
    state = {'last_event_time': last_event_time_iso}
    blob = bucket.blob(key)
    blob.upload_from_string(
      json.dumps(state, indent=2),
      content_type='application/json'
    )
    print(f"Saved state: last_event_time={last_event_time_iso}")
  except Exception as e:
    print(f"Warning: Could not save state: {e}")

def fetch_assets(api_key: str, project_id: str, page_size: int, max_records: int):
  """
  Fetch asset metadata from Nucleus Security API with pagination.

  Args:
    api_key: Nucleus Security API key
    project_id: Nucleus project ID
    page_size: Number of records per page (max 1000)
    max_records: Maximum total records to fetch

  Returns:
    Tuple of (records list, total count)
  """
  endpoint = f"https://app.nucleussec.com/nucleus/api/v1/projects/{project_id}/assets"

  headers = {
    'x-apikey': api_key,
    'Accept': 'application/json',
    'Content-Type': 'application/json',
    'User-Agent': 'GoogleSecOps-NucleusAssetCollector/1.0',
  }

  records = []
  page_num = 0
  backoff = 1.0
  start_index = 0

  while True:
    page_num += 1

    if len(records) >= max_records:
      print(f"Reached max_records limit ({max_records})")
      break

    current_limit = min(page_size, max_records - len(records))
    url = f"{endpoint}?start={start_index}&limit={current_limit}"

    try:
      response = http.request('GET', url, headers=headers)

      # Handle rate limiting with exponential backoff
      if response.status == 429:
        retry_after = int(response.headers.get('Retry-After', str(int(backoff))))
        print(f"Rate limited (429). Retrying after {retry_after}s...")
        time.sleep(retry_after)
        backoff = min(backoff * 2, 30.0)
        continue

      backoff = 1.0

      if response.status != 200:
        print(f"HTTP Error: {response.status}")
        response_text = response.data.decode('utf-8')
        print(f"Response body: {response_text}")
        return [], 0

      data = json.loads(response.data.decode('utf-8'))

      # Nucleus API returns a list of assets directly
      if isinstance(data, list):
        page_results = data
      else:
        page_results = data.get('assets', data.get('results', []))

      if not page_results:
        print(f"No more results (empty page)")
        break

      print(f"Page {page_num}: Retrieved {len(page_results)} assets")
      records.extend(page_results)

      # Check for more results
      if len(page_results) < current_limit:
        print(f"Reached last page (size={len(page_results)} < limit={current_limit})")
        break

      start_index += len(page_results)

    except Exception as e:
      print(f"Error fetching assets: {e}")
      return [], 0

  print(f"Retrieved {len(records)} total assets from {page_num} pages")
  return records, len(records)

requirements.txt:

functions-framework==3.*
google-cloud-storage==2.*
urllib3>=2.0.0

Click Deploy to save and deploy the function.
Wait for deployment to complete (2-3 minutes).

Note: The Pub/Sub trigger configuration automatically creates the necessary subscriptions and permissions.

Create Cloud Scheduler job

Cloud Scheduler will publish messages to the Pub/Sub topic at regular intervals, triggering the Cloud Run function.

In the GCP Console, go to Cloud Scheduler.
Click Create Job.

Provide the following configuration details:

Setting	Value
Name	`nucleus-asset-collector-daily`
Region	Select same region as Cloud Run function
Frequency	`0 0 * * *` (daily at midnight)
Timezone	Select timezone (UTC recommended)
Target type	Pub/Sub
Topic	Select the Pub/Sub topic (`nucleus-asset-trigger`)
Message body	`{}` (empty JSON object)

Click Create.

Schedule frequency options

Choose frequency based on log volume and latency requirements:

Frequency	Cron Expression	Use Case
Every 5 minutes	`/5 * * *`	High-volume, low-latency
Every 15 minutes	`/15 * * *`	Medium volume
Every hour	`0 * * * *`	Standard
Every 6 hours	`0 /6 * *`	Low volume, batch processing
Daily	`0 0 * * *`	Asset inventory snapshots (recommended)

Test the integration

In the Cloud Scheduler console, find your job.
Click Force run to trigger the job manually.
Wait a few seconds.
Go to Cloud Run > Services.
Click on your function name (nucleus-asset-collector).
Click the Logs tab.

Verify the function executed successfully. Look for:

Starting asset metadata collection at YYYY-MM-DDTHH:MM:SS+00:00
Page 1: Retrieved X assets
Wrote X records to gs://nucleus-asset-logs/nucleus-assets/assets_YYYYMMDD_HHMMSS.ndjson
Successfully processed X asset records

Go to Cloud Storage > Buckets.
Click on your bucket name (nucleus-asset-logs).
Navigate to the prefix folder (nucleus-assets/).
Verify that a new .ndjson file was created with the current timestamp.

If you see errors in the logs:

HTTP 401: Check the API key in environment variables
HTTP 403: Verify the API key has read access to the project
HTTP 429: Rate limiting - function will automatically retry with backoff
Missing environment variables: Check all required variables are set

Retrieve the Google SecOps service account

Google SecOps uses a unique service account to read data from your GCS bucket. You must grant this service account access to your bucket.

Get the service account email

Go to SIEM Settings > Feeds.
Click Add New Feed.
Click Configure a single feed.
In the Feed name field, enter a name for the feed (for example, Nucleus Asset Metadata Logs).
Select Google Cloud Storage V2 as the Source type.
Select Nucleus Asset Metadata as the Log type.
Click Get Service Account.

A unique service account email will be displayed, for example:

chronicle-12345678@chronicle-gcp-prod.iam.gserviceaccount.com

Copy this email address for use in the next step.

Note: Each Google SecOps instance has a unique service account. Don't use service accounts from other documentation or examples.
Click Next.
Specify values for the following input parameters:
- Storage bucket URL: Enter the GCS bucket URI with the prefix path:
```
gs://nucleus-asset-logs/nucleus-assets/
```
  - Replace:
    - nucleus-asset-logs: Your GCS bucket name.
    - nucleus-assets: Optional prefix/folder path where logs are stored (leave empty for root).
Note: Always include the trailing slash (/) at the end of the URI.
- Source deletion option: Select the deletion option according to your preference:
  - Never: Never deletes any files after transfers (recommended for testing).
  - Delete transferred files: Deletes files after successful transfer.
  - Delete transferred files and empty directories: Deletes files and empty directories after successful transfer.
    
    Note: If you select a deletion option, the service account must have Storage Object Admin role instead of Storage Object Viewer. Update IAM permissions accordingly.
- Maximum File Age: Include files modified in the last number of days (default is 180 days)
- Asset namespace: The asset namespace
- Ingestion labels: The label to be applied to the events from this feed
Click Next.
Review your new feed configuration in the Finalize screen, and then click Submit.

Grant IAM permissions to the Google SecOps service account

The Google SecOps service account needs Storage Object Viewer role on your GCS bucket.

Go to Cloud Storage > Buckets.
Click on your bucket name (for example, nucleus-asset-logs).
Go to the Permissions tab.
Click Grant access.
Provide the following configuration details:
- Add principals: Paste the Google SecOps service account email
- Assign roles: Select Storage Object Viewer
Click Save.

Note: If you plan to use the deletion option "Delete transferred files" or "Delete transferred files and empty directories," grant Storage Object Admin role instead of Storage Object Viewer.

UDM mapping table

Log Field	UDM Mapping	Logic
host_score_total, host_complianced_score, host_data_sensitivity_score, host_public, asset_tags	entity.asset.attribute.labels	Labels merged from host_score_total as "Host Score Total", host_complianced_score as "Host Complianced Score", host_data_sensitivity_score as "Host Data Sensitivity Score", host_public as "Host Public", and asset_tags parsed as key-value pairs
asset_name	entity.asset.hostname	Extracted from asset_name using grok pattern if contains "http"
ip_address	entity.asset.ip	Merged from ip_address
asset_id	entity.asset.product_object_id	Value copied directly if not empty
asset_name	entity.url	Extracted from asset_name using grok pattern if contains "http" and url_path not empty
	metadata.entity_type	Set to "ASSET"
	metadata.product_name	Set to "Nucleus Unified Vulnerability Management"
	metadata.vendor_name	Set to "NUCLEUS"

Need more help? Get answers from Community members and Google SecOps professionals.