Collect Citrix Monitor Service logs

Supported in:

Google secops SIEM

This document explains how to ingest Citrix Monitor Service logs to Google Security Operations using Google Cloud Storage. Citrix Monitor Service is part of Citrix DaaS (formerly Citrix Virtual Apps and Desktops Service) and provides an OData v4 API for monitoring data about machines, sessions, connections, applications, and users across your Citrix environment. A Cloud Run function polls the Citrix Monitor Service OData API on a schedule and writes the collected logs to a GCS bucket, from which Google SecOps ingests them.

Before you begin

Make sure 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 functions, Pub/Sub topics, and Cloud Scheduler jobs
Permissions to create service accounts and manage IAM roles
Privileged access to Citrix Cloud tenant with administrator role
Citrix Cloud API credentials (Client ID, Client Secret, Customer ID)

Collect Citrix Monitor Service API credentials

Sign in to the Citrix Cloud Console.
Go to Identity and Access Management > API Access.
Click Create Client.
Copy and save in a secure location the following details:
- Client ID
- Client Secret
- Customer ID (visible at the top of the Citrix Cloud console)
- API Base URL (based on your region):
  - US/EU/AP-S: https://api.cloud.com
  - Japan: https://api.citrixcloud.jp
  - US Gov: https://api.cloud.us
Note: Use the endpoint based on the geographical region you selected while accessing the Citrix Monitor Service data for DaaS. For example, US/EU/AP-S region uses https://api.cloud.com/monitorodata, Japan region uses https://api.citrixcloud.jp/monitorodata, and US Gov region uses https://api.cloud.us/monitorodata.

Test API access

Test your credentials before proceeding with the integration:

# Replace with your actual credentials
CITRIX_CUSTOMER_ID="your-customer-id"
CITRIX_CLIENT_ID="your-client-id"
CITRIX_CLIENT_SECRET="your-client-secret"
API_BASE="https://api.cloud.com"

# Get bearer token
TOKEN=$(curl -s -X POST "${API_BASE}/cctrustoauth2/${CITRIX_CUSTOMER_ID}/tokens/clients" \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "grant_type=client_credentials&client_id=${CITRIX_CLIENT_ID}&client_secret=${CITRIX_CLIENT_SECRET}" \
  | python3 -c "import sys,json; print(json.load(sys.stdin)['access_token'])")

# Test Monitor OData API access
curl -v "${API_BASE}/monitorodata/Machines?\$top=1" \
  -H "Authorization: CWSAuth bearer=${TOKEN}" \
  -H "Citrix-CustomerId: ${CITRIX_CUSTOMER_ID}" \
  -H "Accept: application/json"

If you receive an HTTP 200 response with JSON data, your credentials are working correctly.

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, `citrix-monitor-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.

Create service account for Cloud Run function

The Cloud Run function needs a service account with permissions to write to GCS bucket.

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 citrix-monitor-collector-sa.
- Service account description: Enter Service account for Cloud Run function to collect Citrix Monitor Service logs.
Click Create and Continue.
In the Grant this service account access to project section:
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 your bucket name.
Go to the Permissions tab.
Click Grant access.
Provide the following configuration details:
- Add principals: Enter the service account email (citrix-monitor-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 citrix-monitor-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 Citrix Monitor Service OData 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 citrix-monitor-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 (citrix-monitor-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 (citrix-monitor-collector-sa).

Setting	Value
Service name	`citrix-monitor-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
`GCS_BUCKET`	`citrix-monitor-logs`
`GCS_PREFIX`	`citrix_monitor`
`STATE_KEY`	`citrix_monitor/state.json`
`CITRIX_CLIENT_ID`	`your-client-id`
`CITRIX_CLIENT_SECRET`	`your-client-secret`
`CITRIX_CUSTOMER_ID`	`your-customer-id`
`API_BASE`	`https://api.cloud.com`
`ENTITIES`	`Machines,Sessions,Connections,Applications,Users`
`PAGE_SIZE`	`1000`
`LOOKBACK_MINUTES`	`75`
`USE_TIME_FILTER`	`true`

Scroll down in the Variables & Secrets tab to Requests:
- Request timeout: Enter 600 seconds (10 minutes).
Go to the Settings tab in Containers:
- In the Resources section:
  - Memory: Select 512 MiB or higher.
  - CPU: Select 1.
- Click Done.
Scroll down to Execution environment:
- Select Default (recommended).
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 Function 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, timedelta, timezone
import uuid
import time

# Citrix Cloud OAuth2 endpoint template
TOKEN_URL_TMPL = "{api_base}/cctrustoauth2/{customerid}/tokens/clients"
DEFAULT_API_BASE = "https://api.cloud.com"
MONITOR_BASE_PATH = "/monitorodata"

# 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()

def http_post_form(url, data_dict):
        """POST form data to get authentication token."""
        encoded_data = urllib3.request.urlencode(data_dict)
        response = http.request(
                'POST',
                url,
                body=encoded_data,
                headers={
                        'Accept': 'application/json',
                        'Content-Type': 'application/x-www-form-urlencoded'
                }
        )
        return json.loads(response.data.decode('utf-8'))

def http_get_json(url, headers):
        """GET JSON data from API endpoint."""
        response = http.request('GET', url, headers=headers)
        if response.status == 429:
                retry_after = int(response.headers.get('Retry-After', '10'))
                print(f"Rate limited (429). Retrying after {retry_after}s...")
                time.sleep(retry_after)
                response = http.request('GET', url, headers=headers)
        if response.status != 200:
                raise Exception(f"HTTP {response.status}: {response.data.decode('utf-8')[:500]}")
        return json.loads(response.data.decode('utf-8'))

def get_citrix_token(api_base, customer_id, client_id, client_secret):
        """Get Citrix Cloud authentication token."""
        url = TOKEN_URL_TMPL.format(
                api_base=api_base.rstrip('/'),
                customerid=customer_id
        )
        payload = {
                'grant_type': 'client_credentials',
                'client_id': client_id,
                'client_secret': client_secret
        }
        response = http_post_form(url, payload)
        return response['access_token']

def build_entity_url(api_base, entity, filter_query=None, top=None):
        """Build OData URL with optional filter and pagination."""
        base = api_base.rstrip('/') + MONITOR_BASE_PATH + '/' + entity
        params = []
        if filter_query:
                encoded_filter = urllib3.request.urlencode({'$filter': filter_query})[9:]
                params.append('$filter=' + encoded_filter)
        if top:
                params.append('$top=' + str(top))
        return base + ('?' + '&'.join(params) if params else '')

def fetch_entity_rows(entity, start_iso=None, end_iso=None, page_size=1000, headers=None, api_base=DEFAULT_API_BASE):
        """Fetch entity data with optional time filtering and OData pagination."""
        first_url = None
        if start_iso and end_iso:
                filter_query = f"(ModifiedDate ge {start_iso} and ModifiedDate lt {end_iso})"
                first_url = build_entity_url(api_base, entity, filter_query, page_size)
        else:
                first_url = build_entity_url(api_base, entity, None, page_size)

        url = first_url
        while url:
                try:
                        data = http_get_json(url, headers)
                        items = data.get('value', [])
                        for item in items:
                                yield item
                        url = data.get('@odata.nextLink')
                except Exception as e:
                        if 'Bad Request' in str(e) and start_iso and end_iso:
                                print(f"ModifiedDate filter not supported for {entity}, falling back to unfiltered query")
                                url = build_entity_url(api_base, entity, None, page_size)
                                start_iso = None
                                end_iso = None
                                continue
                        else:
                                raise

def load_state(bucket, key):
        """Read the last processed timestamp from GCS state file."""
        try:
                blob = bucket.blob(key)
                if blob.exists():
                        content = blob.download_as_text()
                        state = json.loads(content)
                        timestamp_str = state.get('last_hour_utc')
                        if timestamp_str:
                                return datetime.fromisoformat(timestamp_str.replace('Z', '+00:00')).replace(tzinfo=None)
        except Exception as e:
                print(f"Warning: Could not load state: {str(e)}")
        return None

def save_state(bucket, key, dt_utc):
        """Write the current processed timestamp to GCS state file."""
        state = {'last_hour_utc': dt_utc.isoformat() + 'Z'}
        blob = bucket.blob(key)
        blob.upload_from_string(
                json.dumps(state, separators=(',', ':')),
                content_type='application/json'
        )

def write_ndjson_to_gcs(bucket, key, rows):
        """Write rows as NDJSON to GCS."""
        body_lines = []
        for row in rows:
                json_line = json.dumps(row, separators=(',', ':'), ensure_ascii=False)
                body_lines.append(json_line)
        body = '\n'.join(body_lines) + '\n'
        blob = bucket.blob(key)
        blob.upload_from_string(body, content_type='application/x-ndjson')

@functions_framework.cloud_event
def main(cloud_event):
        """
        Cloud Run function triggered by Pub/Sub to fetch Citrix Monitor Service logs and write to GCS.

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

        # Get environment variables
        bucket_name = os.environ.get('GCS_BUCKET')
        prefix = os.environ.get('GCS_PREFIX', 'citrix_monitor').strip('/')
        state_key = os.environ.get('STATE_KEY') or f"{prefix}/state.json"
        customer_id = os.environ.get('CITRIX_CUSTOMER_ID')
        client_id = os.environ.get('CITRIX_CLIENT_ID')
        client_secret = os.environ.get('CITRIX_CLIENT_SECRET')
        api_base = os.environ.get('API_BASE', DEFAULT_API_BASE)
        entities = [e.strip() for e in os.environ.get('ENTITIES', 'Machines,Sessions,Connections,Applications,Users').split(',') if e.strip()]
        page_size = int(os.environ.get('PAGE_SIZE', '1000'))
        lookback_minutes = int(os.environ.get('LOOKBACK_MINUTES', '75'))
        use_time_filter = os.environ.get('USE_TIME_FILTER', 'true').lower() == 'true'

        if not all([bucket_name, customer_id, client_id, client_secret]):
                print('Error: Missing required environment variables')
                return

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

                # Time window calculation
                now = datetime.utcnow()
                fallback_hour = (now - timedelta(minutes=lookback_minutes)).replace(minute=0, second=0, microsecond=0)
                last_processed = load_state(bucket, state_key)
                target_hour = (last_processed + timedelta(hours=1)) if last_processed else fallback_hour
                start_iso = target_hour.isoformat() + 'Z'
                end_iso = (target_hour + timedelta(hours=1)).isoformat() + 'Z'

                # Authentication
                token = get_citrix_token(api_base, customer_id, client_id, client_secret)
                headers = {
                        'Authorization': f'CWSAuth bearer={token}',
                        'Citrix-CustomerId': customer_id,
                        'Accept': 'application/json',
                        'Accept-Encoding': 'gzip, deflate, br',
                        'User-Agent': 'citrix-monitor-gcs-collector/1.0'
                }

                total_records = 0

                # Process each entity type
                for entity in entities:
                        rows_batch = []
                        try:
                                entity_generator = fetch_entity_rows(
                                        entity=entity,
                                        start_iso=start_iso if use_time_filter else None,
                                        end_iso=end_iso if use_time_filter else None,
                                        page_size=page_size,
                                        headers=headers,
                                        api_base=api_base
                                )

                                for row in entity_generator:
                                        rows_batch.append(row)

                                        # Write in batches to avoid memory issues
                                        if len(rows_batch) >= 1000:
                                                gcs_key = f"{prefix}/{entity}/year={target_hour.year:04d}/month={target_hour.month:02d}/day={target_hour.day:02d}/hour={target_hour.hour:02d}/part-{uuid.uuid4().hex}.ndjson"
                                                write_ndjson_to_gcs(bucket, gcs_key, rows_batch)
                                                total_records += len(rows_batch)
                                                rows_batch = []

                        except Exception as ex:
                                print(f"Error processing entity {entity}: {str(ex)}")
                                continue

                        # Write remaining records
                        if rows_batch:
                                gcs_key = f"{prefix}/{entity}/year={target_hour.year:04d}/month={target_hour.month:02d}/day={target_hour.day:02d}/hour={target_hour.hour:02d}/part-{uuid.uuid4().hex}.ndjson"
                                write_ndjson_to_gcs(bucket, gcs_key, rows_batch)
                                total_records += len(rows_batch)

                # Update state file
                save_state(bucket, state_key, target_hour)

                print(f"Successfully processed {total_records} records for hour {start_iso}")
                print(f"Entities processed: {', '.join(entities)}")

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

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: This script is provided as an example and is not officially supported. We welcome feedback about how we can improve it. To submit feedback, click Send Feedback > Google SecOps Security Product Feedback on this page.

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	`citrix-monitor-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 (`citrix-monitor-trigger`)
Message body	`{}` (empty JSON object)

Click Create.

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 the function name (citrix-monitor-collector).
Click the Logs tab.

Verify the function executed successfully. Look for:

Successfully processed X records for hour YYYY-MM-DDTHH:MM:SSZ
Entities processed: Machines, Sessions, Connections, Applications, Users

Go to Cloud Storage > Buckets.
Click on your bucket name.
Navigate to the prefix folder (citrix_monitor/).
Verify that new .ndjson files were created.

If you see errors in the logs:

HTTP 401: Check API credentials in environment variables
HTTP 403: Verify the Citrix Cloud account has administrator permissions
HTTP 429: Rate limiting - the function will automatically retry with backoff
Missing environment variables: Check all required variables are set

Configure a feed in Google SecOps to ingest Citrix Monitor Service 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, Citrix Monitor Service logs).
Select Google Cloud Storage V2 as the Source type.
Select Citrix Monitor 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. You will use it in the next step.

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://citrix-monitor-logs/citrix_monitor/
```
  - Replace:
    - citrix-monitor-logs: Your GCS bucket name.
    - citrix_monitor: 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 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.

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
`additional_user_id_label`	`additional.fields`	Merged
`CreatedDate`	`metadata.event_timestamp`	Parsed as `ISO8601`
`event_type`	`metadata.event_type`	Directly mapped
`label_Connection_State`	`metadata.ingestion_labels`	Merged
`label_Log_On_Duration`	`metadata.ingestion_labels`	Merged
`label_Session_Key`	`metadata.ingestion_labels`	Merged
`Machine.AgentVersion`	`metadata.product_version`	Directly mapped
`Machine.DnsName`	`network.dns_domain`	Directly mapped
`applicationInstance.Application.BrowserName`	`network.http.user_agent`	Directly mapped
`CurrentConnectionId`	`network.session_id`	Directly mapped
`Machine.HostedMachineName`	`principal.administrative_domain`	Directly mapped
`Machine.Id`	`principal.asset.asset_id`	Directly mapped
`MachineId`	`principal.asset.asset_id`	Directly mapped
`Machine.HostingServerName`	`principal.hostname`	Directly mapped
`Machine.IPAddress`	`principal.ip`	Merged
`connection.ClientAddress`	`principal.ip`	Merged
`connection.ConnectedViaIPAddress`	`principal.ip`	Merged
`user`	`principal.user.email_addresses`	Mapped: `^.+@.+$` → `user`
`Machine.AssociatedUserFullNames`	`principal.user.user_display_name`	Directly mapped
`Machine.Sid`	`principal.user.windows_sid`	Directly mapped
`User.Domain`	`target.administrative_domain`	Directly mapped
`applicationInstance.Application.Name`	`target.application`	Directly mapped
`connection.LaunchedViaIPAddress`	`target.ip`	Merged
`applicationInstance.Application.Path`	`target.process.file.full_path`	Directly mapped
`Machine.Hash`	`target.process.file.md5`	Directly mapped
`applicationInstance.Application.AdminFolder`	`target.process.parent_process.file.full_path`	Directly mapped
`User.Upn`	`target.user.email_addresses`	Merged
`User.FullName`	`target.user.user_display_name`	Directly mapped
`User.UserName`	`target.user.userid`	Directly mapped
`User.Sid`	`target.user.windows_sid`	Directly mapped
N/A	`metadata.event_type`	Constant: `GENERIC_EVENT`
N/A	`metadata.product_name`	Constant: `CITRIX_MONITOR`
N/A	`metadata.vendor_name`	Constant: `CITRIX_MONITOR`
N/A	`target.platform`	Constant: `WINDOWS`

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