Collect Nagios XI logs

Supported in:

Google secops SIEM

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

Nagios XI is a comprehensive infrastructure monitoring solution that provides monitoring of servers, networks, applications, and services. It tracks host and service status, performance metrics, and generates alerts for IT infrastructure issues through its REST API.

Before you begin

Ensure that you have the following prerequisites:

A Google SecOps instance
A GCP project with Cloud Storage, Cloud Run, Pub/Sub, and Cloud Scheduler APIs 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 Nagios XI with user management permissions
Nagios XI version 5 or later (REST API support)

Configure Nagios XI API access

To enable Google SecOps to retrieve monitoring data, you need to create a user account with API access and read-only permissions.

Create a read-only user with API access

Sign in to the Nagios XI web interface with administrator privileges.
Go to Admin > Manage Users.
Click Add New User.
Provide the following configuration details:
- Username: Enter a descriptive name (for example, chronicle-integration)
- Password: Enter a secure password
- Name: Enter Chronicle Integration User
- Email Address: Enter a valid email address
In the Security Settings section, configure the following:
- Authorization Level: Select User
- Can see all hosts and services: Check this option
- Read-only access: Check this option
- API access: Check this option
Uncheck the following options:
- Force Password Change at Next Login
- Email User Account Information
- Create as Monitoring Contact
Ensure Account Enabled is checked.
Click Add User.

Retrieve the API key

In the Manage Users page, click on the user account (chronicle-integration).
In the user account settings page, locate the API Key field.
Copy the API key value.

Note: Each user has a unique API key. If you need to regenerate the API key, click Generate new API key in the user account settings. The old API key will be invalidated immediately.
Note: Store the API key securely. It provides read access to all monitoring data in Nagios XI.

Verify permissions

To verify the account has the required permissions:

Sign in to Nagios XI with the chronicle-integration user account.
Go to Home > Host Status.
If you can see all monitored hosts and services, you have the required permissions.
If you cannot see hosts or services, contact your administrator to grant Can see all hosts and services permission.

Test API access

Test your credentials before proceeding with the integration:

# Replace with your actual values
NAGIOS_HOST="https://your-nagios-server.example.com"
API_KEY="your-api-key"

# Test API access - query host status
curl -k "${NAGIOS_HOST}/nagiosxi/api/v1/objects/hoststatus?apikey=${API_KEY}&pretty=1"

A successful response returns a JSON object containing host status information.

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, `nagios-xi-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

In the GCP Console, go to IAM & Admin > Service Accounts.
Click Create Service Account.
Provide the following configuration details:
- Service account name: Enter nagios-logs-collector-sa
- Service account description: Enter Service account for Cloud Run function to collect Nagios XI 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.

Grant IAM permissions on GCS bucket

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

Create Pub/Sub topic

In the GCP Console, go to Pub/Sub > Topics.
Click Create topic.
Provide the following configuration details:
- Topic ID: Enter nagios-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 Nagios XI REST 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 nagios-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 nagios-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 nagios-logs-collector-sa

Setting	Value
Service name	`nagios-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`	`nagios-xi-logs`	GCS bucket name
`GCS_PREFIX`	`nagios-xi`	Prefix for log files
`STATE_KEY`	`nagios-xi/state.json`	State file path
`NAGIOS_BASE_URL`	`https://your-nagios-server.example.com`	Nagios XI base URL
`NAGIOS_API_KEY`	`your-api-key`	Nagios XI API key
`MAX_RECORDS`	`1000`	Max records per endpoint per run
`PAGE_SIZE`	`200`	Records per API 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
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

http = urllib3.PoolManager(
  timeout=urllib3.Timeout(connect=5.0, read=30.0),
  retries=False,
)

storage_client = storage.Client()

GCS_BUCKET = os.environ.get('GCS_BUCKET')
GCS_PREFIX = os.environ.get('GCS_PREFIX', 'nagios-xi')
STATE_KEY = os.environ.get('STATE_KEY', 'nagios-xi/state.json')
NAGIOS_BASE_URL = os.environ.get('NAGIOS_BASE_URL', '').rstrip('/')
NAGIOS_API_KEY = os.environ.get('NAGIOS_API_KEY')
MAX_RECORDS = int(os.environ.get('MAX_RECORDS', '1000'))
PAGE_SIZE = int(os.environ.get('PAGE_SIZE', '200'))
LOOKBACK_HOURS = int(os.environ.get('LOOKBACK_HOURS', '24'))

ENDPOINTS = [
  'hoststatus',
  'servicestatus',
  'statehistory',
  'logentries',
]

@functions_framework.cloud_event
def main(cloud_event):
  if not all([GCS_BUCKET, NAGIOS_BASE_URL, NAGIOS_API_KEY]):
    print('Error: Missing required environment variables')
    return

  try:
    bucket = storage_client.bucket(GCS_BUCKET)
    state = load_state(bucket)
    now = datetime.now(timezone.utc)

    if isinstance(state, dict) and state.get('last_event_time'):
      try:
        last_val = state['last_event_time']
        if last_val.endswith('Z'):
          last_val = last_val[:-1] + '+00:00'
        last_time = datetime.fromisoformat(last_val)
        last_time = last_time - timedelta(minutes=2)
      except Exception as e:
        print(f"Warning: Could not parse last_event_time: {e}")
        last_time = now - timedelta(hours=LOOKBACK_HOURS)
    else:
      last_time = now - timedelta(hours=LOOKBACK_HOURS)

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

    start_ts = int(last_time.timestamp())
    end_ts = int(now.timestamp())

    all_records = []
    newest_time = None

    for endpoint in ENDPOINTS:
      records, endpoint_newest = fetch_nagios_endpoint(
        endpoint, start_ts, end_ts
      )
      for record in records:
        record['_nagios_endpoint'] = endpoint
      all_records.extend(records)

      if endpoint_newest:
        if newest_time is None or endpoint_newest > newest_time:
          newest_time = endpoint_newest

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

    timestamp = now.strftime('%Y%m%d_%H%M%S')
    object_key = f"{GCS_PREFIX}/nagios_logs_{timestamp}.ndjson"
    blob = bucket.blob(object_key)

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

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

    if newest_time:
      save_state(bucket, newest_time)
    else:
      save_state(bucket, now.isoformat())

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

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

def fetch_nagios_endpoint(endpoint, start_ts, end_ts):
  base_url = f"{NAGIOS_BASE_URL}/nagiosxi/api/v1/objects/{endpoint}"

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

  while True:
    page_num += 1

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

    remaining = min(PAGE_SIZE, MAX_RECORDS - len(records))
    params = [
      f"apikey={NAGIOS_API_KEY}",
      f"starttime={start_ts}",
      f"endtime={end_ts}",
      f"records={remaining}",
      f"start={start_index}",
    ]
    url = f"{base_url}?{'&'.join(params)}"

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

      if response.status == 429:
        retry_after = int(response.headers.get('Retry-After', str(int(backoff))))
        print(f"{endpoint}: 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"{endpoint}: HTTP Error {response.status}")
        response_text = response.data.decode('utf-8')
        print(f"Response body: {response_text}")
        break

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

      record_count = data.get('recordcount', 0)
      result_key = get_result_key(endpoint)
      page_results = data.get(result_key, [])

      if not page_results:
        print(f"{endpoint}: No more results at offset {start_index}")
        break

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

      for event in page_results:
        try:
          event_time = event.get('state_time') or event.get('status_update_time') or event.get('entry_time')
          if event_time:
            if newest_time is None or event_time > newest_time:
              newest_time = event_time
        except Exception as e:
          print(f"Warning: Could not parse event time: {e}")

      if len(page_results) < remaining:
        print(f"{endpoint}: Reached last page (returned {len(page_results)} < {remaining})")
        break

      start_index += len(page_results)

    except Exception as e:
      print(f"{endpoint}: Error fetching logs: {e}")
      break

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

def get_result_key(endpoint):
  key_map = {
    'hoststatus': 'hoststatus',
    'servicestatus': 'servicestatus',
    'statehistory': 'statehistory',
    'logentries': 'logentry',
  }
  return key_map.get(endpoint, endpoint)

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

def save_state(bucket, last_event_time_iso):
  try:
    state = {
      'last_event_time': last_event_time_iso,
      'last_run': datetime.now(timezone.utc).isoformat()
    }
    blob = bucket.blob(STATE_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}")

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

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

Provide the following configuration details:

Setting	Value
Name	`nagios-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 `nagios-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 (nagios-logs-collector-hourly).
Click Force run to trigger the job manually.
Wait a few seconds.
Go to Cloud Run > Services.
Click on nagios-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
hoststatus page 1: Retrieved X events
servicestatus page 1: Retrieved X events
statehistory page 1: Retrieved X events
logentries page 1: Retrieved X events
Wrote X records to gs://nagios-xi-logs/nagios-xi/nagios_logs_YYYYMMDD_HHMMSS.ndjson
Successfully processed X records

Go to Cloud Storage > Buckets.
Click on nagios-xi-logs.
Navigate to the nagios-xi/ folder.
Verify that a new .ndjson file was created with the current timestamp.

If you see errors in the logs:

HTTP 401: Verify the NAGIOS_API_KEY environment variable is correct and the user has API access enabled
HTTP 403: Verify the user account has Can see all hosts and services permission
HTTP 429: Rate limiting -- the function will automatically retry with backoff
Missing environment variables: Verify all required variables are set in the Cloud Run function configuration

Retrieve the Google SecOps service account

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, Nagios XI Logs GCS).
Select Google Cloud Storage V2 as the Source type.
Select Nagios as the Log type.
Click Get Service Account.

A unique service account email is 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://nagios-xi-logs/nagios-xi/
```
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

Go to Cloud Storage > Buckets.
Click on nagios-xi-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
src_ip	has_principal	Set to "true" if merge of src_ip to principal.ip and principal.asset.ip succeeds
src_ip	principal.asset.ip	Value copied directly
src_ip	principal.ip	Value copied directly
jobid	jobid_label.key	Set to "Jobid"
jobid	jobid_label.value	Value copied directly
jobid_label	principal.resource.attribute.labels	Merged from jobid_label
pid	principal.process.pid	Value copied directly
ent	metadata.product_event_type	Value copied directly
description	metadata.description	Value copied directly
msg_ip	has_target	Set to "true" if merge of msg_ip to target.ip and target.asset.ip succeeds
msg_ip	target.asset.ip	Value copied directly
msg_ip	target.ip	Value copied directly
port	target.port	Value copied directly and converted to integer
column1	principal.asset.hostname	Value from column1 if ent == "SERVICE ALERT", else from column2 if ent == "SERVICE NOTIFICATION"
column1	principal.hostname	Value from column1 if ent == "SERVICE ALERT", else from column2 if ent == "SERVICE NOTIFICATION"
column1	principal.user.user_display_name	Value copied directly if ent == "SERVICE NOTIFICATION"
column2	security_result.summary	Value from column3 if ent == "SERVICE ALERT" and column2 not empty, else from column3 if ent == "SERVICE NOTIFICATION"
column3	security_result.summary	Value from column3 if ent == "SERVICE ALERT" and column3 not empty, else from column3 if ent == "SERVICE NOTIFICATION"
column4	security_result.severity	Value copied directly if column4 in ["LOW", "MEDIUM", "HIGH", "CRITICAL"] and ent in ["SERVICE NOTIFICATION", "SERVICE ALERT"]
column4	security_result.severity_details	Value copied directly if column4 not in ["LOW", "MEDIUM", "HIGH", "CRITICAL"] and ent in ["SERVICE NOTIFICATION", "SERVICE ALERT"]
has_principal	metadata.event_type	Set to "NETWORK_CONNECTION" if has_principal and has_target true, else "STATUS_UPDATE" if has_principal true, else "USER_UNCATEGORIZED" if has_principal_user true, else "GENERIC_EVENT"
has_target	metadata.event_type
has_principal_user	metadata.event_type
security_result	event.idm.read_only_udm.security_result	Merged from security_result
metadata	event.idm.read_only_udm.metadata	Renamed from metadata
target	event.idm.read_only_udm.target	Renamed from target
principal	event.idm.read_only_udm.principal	Renamed from principal
network	event.idm.read_only_udm.network	Renamed from network
metadata.product_name	metadata.product_name	Set to "NAGIOS"
metadata.vendor_name	metadata.vendor_name	Set to "NAGIOS"

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