Collect Talon logs

Supported in:

Google secops SIEM

This document explains how to ingest Talon logs to Google Security Operations using Google Cloud Storage V2.

Talon (now part of Palo Alto Networks) is an enterprise browser security platform that provides secure browsing, data loss prevention (DLP), and access control for managed and unmanaged devices. After its acquisition, Talon has been integrated into the Prisma Access platform as Prisma Access Browser, with logs forwarded through Strata Logging Service. The Strata Logging Service API provides programmatic access to security event logs.

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 Strata Cloud Manager with administrator permissions
OAuth2 client credentials (client ID, client secret, and TSG ID) from the Palo Alto Networks Hub

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, `talon-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 Talon API credentials

Create OAuth2 client credentials

Sign in to the Palo Alto Networks Hub.
Go to Settings > Service Accounts.
Click Add Service Account.
Provide the following configuration details:
- Name: Enter a descriptive name (for example, Google SecOps Talon Integration).
- Role: Select a role with logging read access.
Click Add.
Copy and save the following details in a secure location:
- Client ID: The OAuth2 client ID
- Client Secret: The OAuth2 client secret
Note the Tenant Service Group (TSG) ID from the Hub URL or Settings page.

Note: The service account must have permissions to access the Strata Logging Service API. Contact your Palo Alto Networks administrator if you need to enable API access.

Determine API base URL

The Strata Logging Service API base URL:

Region	API Base URL
Global	`https://api.strata.paloaltonetworks.com`

Test API access

Test your credentials before proceeding with the integration:

# Replace with your actual credentials
CLIENT_ID="your-client-id"
CLIENT_SECRET="your-client-secret"
TSG_ID="your-tsg-id"

# Get access token
curl -s -X POST "https://auth.apps.paloaltonetworks.com/oauth2/access_token" \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "grant_type=client_credentials&scope=tsg_id:${TSG_ID}" \
  -u "${CLIENT_ID}:${CLIENT_SECRET}"

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 talon-logs-collector-sa
- Service account description: Enter Service account for Cloud Run function to collect Talon 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, talon-logs).
Go to the Permissions tab.
Click Grant access.
Provide the following configuration details:
- Add principals: Enter the service account email (for example, talon-logs-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 talon-logs-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 logs from the Strata Logging Service API and write them 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 talon-logs-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 topic talon-logs-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 talon-logs-collector-sa.

Setting	Value
Service name	`talon-logs-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`	`talon-logs`	GCS bucket name
`GCS_PREFIX`	`talon`	Prefix for log files
`STATE_KEY`	`talon/state.json`	State file path
`CLIENT_ID`	`your-client-id`	OAuth2 client ID
`CLIENT_SECRET`	`your-client-secret`	OAuth2 client secret
`TSG_ID`	`your-tsg-id`	Tenant Service Group ID
`API_BASE_URL`	`https://api.strata.paloaltonetworks.com`	Strata Logging Service API base URL
`MAX_RECORDS`	`5000`	Max records per run
`PAGE_SIZE`	`1000`	Records per page
`LOOKBACK_HOURS`	`24`	Initial lookback period

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', 'talon')
STATE_KEY = os.environ.get('STATE_KEY', 'talon/state.json')
CLIENT_ID = os.environ.get('CLIENT_ID')
CLIENT_SECRET = os.environ.get('CLIENT_SECRET')
TSG_ID = os.environ.get('TSG_ID')
API_BASE_URL = os.environ.get('API_BASE_URL', 'https://api.strata.paloaltonetworks.com')
MAX_RECORDS = int(os.environ.get('MAX_RECORDS', '5000'))
PAGE_SIZE = int(os.environ.get('PAGE_SIZE', '1000'))
LOOKBACK_HOURS = int(os.environ.get('LOOKBACK_HOURS', '24'))

AUTH_URL = "https://auth.apps.paloaltonetworks.com/oauth2/access_token"

def to_unix_millis(dt: datetime) -> int:
  """Convert datetime to Unix epoch milliseconds."""
  if dt.tzinfo is None:
    dt = dt.replace(tzinfo=timezone.utc)
  dt = dt.astimezone(timezone.utc)
  return int(dt.timestamp() * 1000)

def parse_datetime(value: str) -> datetime:
  """Parse ISO datetime string to datetime object."""
  if value.endswith("Z"):
    value = value[:-1] + "+00:00"
  return datetime.fromisoformat(value)

def get_access_token():
  """
  Obtain OAuth2 access token using client credentials grant.
  """
  import base64
  credentials = base64.b64encode(f"{CLIENT_ID}:{CLIENT_SECRET}".encode()).decode()

  headers = {
    'Content-Type': 'application/x-www-form-urlencoded',
    'Authorization': f'Basic {credentials}',
    'Accept': 'application/json'
  }

  body = f"grant_type=client_credentials&scope=tsg_id:{TSG_ID}"

  backoff = 1.0
  for attempt in range(3):
    response = http.request('POST', AUTH_URL, body=body, headers=headers)

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

    if response.status != 200:
      raise RuntimeError(f"Failed to get access token: {response.status} - {response.data.decode('utf-8')}")

    data = json.loads(response.data.decode('utf-8'))
    return data['access_token']

  raise RuntimeError("Failed to get access token after 3 retries")

@functions_framework.cloud_event
def main(cloud_event):
  """
  Cloud Run function triggered by Pub/Sub to fetch Talon
  (Prisma Access Browser) logs and write to GCS.

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

  if not all([GCS_BUCKET, CLIENT_ID, CLIENT_SECRET, TSG_ID]):
    print('Error: Missing required environment variables')
    return

  try:
    bucket = storage_client.bucket(GCS_BUCKET)

    # Load state
    state = load_state(bucket, STATE_KEY)

    # Determine time window
    now = datetime.now(timezone.utc)
    last_time = None

    if isinstance(state, dict) and state.get("last_event_time"):
      try:
        last_time = parse_datetime(state["last_event_time"])
        # Overlap by 2 minutes to catch any delayed events
        last_time = last_time - timedelta(minutes=2)
      except Exception as e:
        print(f"Warning: Could not parse last_event_time: {e}")

    if last_time is None:
      last_time = now - timedelta(hours=LOOKBACK_HOURS)

    print(f"Fetching logs from {last_time.isoformat()} to {now.isoformat()}")

    # Get access token
    token = get_access_token()

    # Fetch logs
    records, newest_event_time = fetch_logs(
      token=token,
      start_time=last_time,
      end_time=now,
      page_size=PAGE_SIZE,
      max_records=MAX_RECORDS,
    )

    if not records:
      print("No new log 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}/logs_{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 with newest event time
    if newest_event_time:
      save_state(bucket, STATE_KEY, newest_event_time)
    else:
      save_state(bucket, STATE_KEY, now.isoformat())

    print(f"Successfully processed {len(records)} 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_logs(token: str, start_time: datetime, end_time: datetime, page_size: int, max_records: int):
  """
  Fetch event logs from Strata Logging Service API
  with pagination and rate limiting.

  Args:
    token: OAuth2 access token
    start_time: Start time for log query
    end_time: End time for log query
    page_size: Number of records per page
    max_records: Maximum total records to fetch

  Returns:
    Tuple of (records list, newest_event_time ISO string)
  """
  api_base = API_BASE_URL.rstrip('/')
  endpoint = f"{api_base}/logging-service/v1/queries"

  headers = {
    'Authorization': f'Bearer {token}',
    'Accept': 'application/json',
    'Content-Type': 'application/json',
    'User-Agent': 'GoogleSecOps-TalonCollector/1.0'
  }

  records = []
  newest_time = None
  page_num = 0
  backoff = 1.0

  # Create log query
  query_body = json.dumps({
    'query': 'SELECT * FROM `firewall.traffic`',
    'startTime': int(start_time.timestamp()),
    'endTime': int(end_time.timestamp()),
    'maxWaitTime': 30000,
    'pageSize': min(page_size, max_records)
  })

  try:
    response = http.request('POST', endpoint, body=query_body, headers=headers)

    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)
      response = http.request('POST', endpoint, body=query_body, headers=headers)

    if response.status not in (200, 201):
      print(f"HTTP Error: {response.status}")
      response_text = response.data.decode('utf-8')
      print(f"Response body: {response_text}")
      return [], None

    data = json.loads(response.data.decode('utf-8'))
    query_id = data.get('queryId')
    query_status = data.get('queryStatus', '')

  except Exception as e:
    print(f"Error creating query: {e}")
    return [], None

  # Poll for results
  results_endpoint = f"{api_base}/logging-service/v1/queries/{query_id}/results"
  scroll_token = None

  while True:
    page_num += 1

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

    try:
      params = {'pageSize': min(page_size, max_records - len(records))}
      if scroll_token:
        params['scrollToken'] = scroll_token

      url = results_endpoint + '?' + '&'.join(f'{k}={v}' for k, v in params.items())
      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

      if response.status == 202:
        print("Query still processing, waiting...")
        time.sleep(5)
        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 records, newest_time

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

      page_results = data.get('result', {}).get('logs', [])

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

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

      # Track newest event time
      for event in page_results:
        try:
          event_ts = event.get('time_generated') or event.get('receive_time')
          if event_ts:
            if isinstance(event_ts, (int, float)):
              event_dt = datetime.fromtimestamp(event_ts, tz=timezone.utc)
              event_time = event_dt.isoformat()
            else:
              event_time = str(event_ts)
            if newest_time is None or parse_datetime(event_time) > parse_datetime(newest_time):
              newest_time = event_time
        except Exception as e:
          print(f"Warning: Could not parse event time: {e}")

      # Check for more results
      scroll_token = data.get('result', {}).get('scrollToken')
      if not scroll_token:
        print("No more pages (no scroll token)")
        break

    except Exception as e:
      print(f"Error fetching logs: {e}")
      return records, newest_time

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

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	`talon-logs-collector-hourly`
Region	Select same region as Cloud Run function
Frequency	`0 * * * *` (every hour, on the hour)
Timezone	Select timezone (UTC recommended)
Target type	Pub/Sub
Topic	Select the topic `talon-logs-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 (recommended)
Every 6 hours	`0 /6 * *`	Low volume, batch processing
Daily	`0 0 * * *`	Historical data collection

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 talon-logs-collector.
Click the Logs tab.

Verify the function executed successfully. Look for:

Fetching logs from YYYY-MM-DDTHH:MM:SS+00:00 to YYYY-MM-DDTHH:MM:SS+00:00
Page 1: Retrieved X events
Wrote X records to gs://talon-logs/talon/logs_YYYYMMDD_HHMMSS.ndjson
Successfully processed X records

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

If you see errors in the logs:

HTTP 401: Check OAuth2 credentials in environment variables
HTTP 403: Verify service account has required permissions in Strata Cloud Manager
HTTP 429: Rate limiting - function will automatically retry with backoff
Missing environment variables: Check all required variables are set

Configure a feed in Google SecOps to ingest Talon logs

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, Talon Logs).
Select Google Cloud Storage V2 as the Source type.
Select Talon 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.

Note: Each Google SecOps instance has a unique service account. Do not 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://talon-logs/talon/
```
  - Replace:
    - talon-logs: Your GCS bucket name.
    - talon: 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.
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.

UDM mapping table

Log Field	UDM Mapping	Logic
user.externalId, user.tenantExternalId, policy.action	additional.fields	Merged with labels for each source field if not empty
timestamp	metadata.event_timestamp	Parsed using date filter with ISO8601 and yyyy-MM-ddTHH:mm:ss.SSSSSSSSSZ formats
has_principal, has_target	metadata.event_type	Set to STATUS_UPDATE if has_principal is true and has_target is false, else GENERIC_EVENT
user.tenantId	metadata.product_deployment_id	Value copied directly if not empty
type	metadata.product_event_type	Value copied directly if not empty
device.deviceUuid	metadata.product_log_id	Value copied directly if not empty
network.protocol	network.application_protocol	Set to "HTTPS" if matches (?i)https
network.http.method	network.http.method	Value copied directly if not empty
device.userAgent	network.http.parsed_user_agent	Value copied directly if not empty
device.userAgent	network.http.user_agent	Value copied directly if not empty
user.tenantName	observer.hostname	Value copied directly if not empty
device.hostname	principal.hostname	Value copied directly if not empty
device.ipAddress	principal.ip	Extracted IP using grok pattern %{IP:prin_ip}, merged if not empty
user.email	principal.user.email_addresses	Merged if matches email regex ^.+@.+$
user.name	principal.user.user_display_name	Value copied directly if not empty
user.id	principal.user.userid	Value copied directly if not empty
device.browserType, device.browserVersion, device.browserBrand, batchId	security_result.about.resource.attribute.labels	Merged with labels for each source field if not empty
policy.ruleId	security_result.rule_id	Value copied directly if not empty
policy.ruleDescription	security_result.summary	Value copied directly if not empty
device.os.type, event_platform	target.platform	Set to WINDOWS if device.os.type == "windows", else MAC if event_platform in ["Mac","iOS"], else LINUX if event_platform == "Lin"
	metadata.product_name	Set to "Talon"
	metadata.vendor_name	Set to "TALON"

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