OCI Monitoring Should Have Event Rule For NSG Changes

Using Console

Below are step‑by‑step instructions to configure an OCI Event Rule for NSG changes and integrate it with OCI Alerting (Notifications) using the OCI Console.

1. Prerequisites

You must have permissions (policies) to:
- Use events-rules in the compartment
- Use notifications-topics and subscriptions
Identify the compartment where your Network Security Groups (NSGs) reside.

2. Create (or Reuse) a Notifications Topic

In the OCI Console, open the navigation menu and go to
Developer Services → Notifications.
Make sure the correct Compartment is selected.
Click Create Topic.
Enter:
- Name: e.g. nsg-change-alerts
- Description: e.g. Alerts for NSG configuration changes
Click Create.

Open the topic you just created (e.g. nsg-change-alerts).
Under Subscriptions, click Create Subscription.
Choose Protocol: e.g. Email.
Enter your Email address.
Click Create.
Confirm the subscription from your email (click the confirmation link).

(Use HTTPS/Slack/PagerDuty/etc. instead if desired.)

3. Create the Event Rule for NSG Changes

Open the navigation menu and go to
Observability & Management → Events Service → Rules.
Make sure the Compartment is set to where you want the rule stored (often same as NSGs, or a central logging/ops compartment).
Click Create Rule.

3.1. Basic Rule Details

Name: e.g. Detect-NSG-Changes
Description: e.g. Triggers when NSG configuration is modified or deleted
Rule State: ensure it is Enabled.

3.2. Define the Event Pattern

In Rule Conditions, choose:
- Rule Type: Event Type
Configure:
- Service: Virtual Cloud Network (VCN) or Networking (name may vary slightly).
- Resource Type: NetworkSecurityGroup.
For Event Type, select the operations you care about (at minimum):
- Update Network Security Group
- Change Security Rules (if separately available)
- Delete Network Security Group
- Optionally also:
  - Create Network Security Group (to track creation)

If the console uses a JSON pattern editor, the filter will conceptually look like:

{
  "eventType": [
    "com.oraclecloud.nsg.updatenetworksecuritygroup",
    "com.oraclecloud.nsg.deletenetworksecuritygroup",
    "com.oraclecloud.nsg.changesecurityrules"
  ]
}

(Use the UI dropdowns rather than typing JSON if available.)

If needed, restrict by Compartment of the NSGs (often you choose the same application compartment).

4. Attach an Action to Send Alerts

In the Actions section of the rule, click + Add Action.
Choose Action Type: Notifications.
Select the Notifications Topic you created earlier
(e.g. nsg-change-alerts).
Optionally, add a Message Format or specify custom payload if offered; otherwise, leave defaults.
Click Create (or Create Rule) to save the rule.

5. (Optional) Centralize or Enhance Monitoring

If you want more advanced workflows (e.g. send events to Logging or custom processors):

Use Service Connector Hub:
- Source: Events Service
- Target: Logging or Function for richer analysis.

OCI Monitoring Alarms are metric‑based, so NSG changes are generally alerted via Events + Notifications as configured above.

6. Test the Configuration

Go to Networking → Virtual Cloud Networks → Network Security Groups.
Pick an NSG in the monitored compartment.
Perform one of the actions you configured:
- Modify a security rule (e.g., change port or CIDR).
- Add or remove a rule.
Within a short time, verify you receive an email (or other protocol) from the Notifications topic indicating an NSG change event.

Once this works, you have successfully remediated the misconfiguration: OCI now generates and sends alerts for NSG changes using OCI’s Event Rules and Notifications.

Using CLI

Below is a simple, CLI‑only way to get alerts when any Network Security Group (NSG) is changed, using OCI Events + Notifications (which is what OCI “alerting/monitoring” for config changes is built on).Replace all <PLACEHOLDER> values with your own OCIDs / data.

1. Prereqs

OCI CLI installed and configured (oci setup config)
You know:
- Tenancy OCID: <TENANCY_OCID>
- Target compartment OCID where NSGs live: <COMPARTMENT_OCID>
- Region is set in your CLI config

2. Create a Notifications topic

oci ons topic create \
  --compartment-id <COMPARTMENT_OCID> \
  --name "nsg-change-topic" \
  --description "Topic for NSG change alerts"

Capture the id from the output as <TOPIC_OCID>.

3. Create a subscription on the topic (e.g., email)

oci ons subscription create \
  --topic-id <TOPIC_OCID> \
  --protocol EMAIL \
  --subscription-endpoint "<YOUR_EMAIL_ADDRESS>"

Confirm the email subscription when you receive the confirmation email.

4. Create the Events rule for NSG changes

Event types for NSGs include:

com.oraclecloud.virtualnetwork.createnetworksecuritygroup
com.oraclecloud.virtualnetwork.updatenetworksecuritygroup
com.oraclecloud.virtualnetwork.deletenetworksecuritygroup

Create the rule:

oci events rule create \
  --compartment-id <TENANCY_OCID> \
  --display-name "NSG-Changes-Rule" \
  --is-enabled true \
  --condition '{
    "eventType": [
      "com.oraclecloud.virtualnetwork.createnetworksecuritygroup",
      "com.oraclecloud.virtualnetwork.updatenetworksecuritygroup",
      "com.oraclecloud.virtualnetwork.deletenetworksecuritygroup"
    ],
    "data": {
      "compartmentId": "<COMPARTMENT_OCID>"
    }
  }' \
  --actions '{
    "actions": [
      {
        "actionType": "ONS",
        "isEnabled": true,
        "topicId": "<TOPIC_OCID>"
      }
    ]
  }'

Notes:

Use <TENANCY_OCID> for the rule compartment (best practice), and filter to <COMPARTMENT_OCID> in the condition.
If you want this to fire for all compartments, drop the data.compartmentId filter.

5. Test

Modify an NSG (e.g., add a rule) in <COMPARTMENT_OCID>.
Verify that you receive an email from the Notifications topic.

This satisfies the requirement “OCI Monitoring Should Have Event Rule For NSG Changes” using OCI CLI.

Using Python

Below is a practical way to enforce “OCI Monitoring Should Have Event Rule For NSG Changes” and wire it into alerting using OCI Events + Notifications in Python.

1. What you will create

In one Python run you will:

Create an ONS Topic (Notifications).
Create an Email Subscription to that topic.
Create an Events Rule that listens for NSG create / update / delete events.
Route matching events to the ONS topic (so you get alerts).

2. Prerequisites

OCI Python SDK installed:
pip install oci
OCI config file (~/.oci/config) with a profile, e.g. DEFAULT.
Your:
- compartment_ocid
- region
- An email address for alerts.

3. Event Types for NSG Changes

Use these event types for Network Security Groups (NSGs):

"com.oraclecloud.virtualnetwork.create.networksecuritygroup"
"com.oraclecloud.virtualnetwork.update.networksecuritygroup"
"com.oraclecloud.virtualnetwork.delete.networksecuritygroup"

Condition (rule) expression:

{
  "eventType": [
    "com.oraclecloud.virtualnetwork.create.networksecuritygroup",
    "com.oraclecloud.virtualnetwork.update.networksecuritygroup",
    "com.oraclecloud.virtualnetwork.delete.networksecuritygroup"
  ]
}

4. Full Python Example

import oci
import json
import time

# ---------- CONFIG ----------
PROFILE = "DEFAULT"  # OCI CLI profile
COMPARTMENT_OCID = "<your_compartment_ocid>"
ALERT_EMAIL = "<your_email@example.com>"
TOPIC_NAME = "nsg-change-alerts-topic"
TOPIC_DESC = "Alerts when NSGs are created, updated, or deleted"
RULE_DISPLAY_NAME = "NSG Change Events Rule"
RULE_DESCRIPTION = "Triggers on NSG create/update/delete and sends notification"
REGION = "<your_region>"  # e.g. "us-ashburn-1"
# ----------------------------

config = oci.config.from_file("~/.oci/config", PROFILE)
config["region"] = REGION

ons_client = oci.ons.NotificationControlPlaneClient(config)
events_client = oci.events.EventsClient(config)


def create_topic_if_not_exists():
    topics = oci.pagination.list_call_get_all_results(
        ons_client.list_topics,
        compartment_id=COMPARTMENT_OCID
    ).data

    for t in topics:
        if t.name == TOPIC_NAME:
            print(f"Topic already exists: {t.topic_id}")
            return t

    create_details = oci.ons.models.CreateTopicDetails(
        compartment_id=COMPARTMENT_OCID,
        name=TOPIC_NAME,
        description=TOPIC_DESC
    )
    topic = ons_client.create_topic(create_details).data
    print(f"Created topic: {topic.topic_id}")
    return topic


def create_email_subscription_if_not_exists(topic_ocid):
    subs = oci.pagination.list_call_get_all_results(
        ons_client.list_subscriptions,
        compartment_id=COMPARTMENT_OCID
    ).data

    for s in subs:
        if s.topic_id == topic_ocid and s.endpoint == ALERT_EMAIL and s.protocol == "EMAIL":
            print(f"Subscription already exists: {s.id}")
            return s

    create_sub_details = oci.ons.models.CreateSubscriptionDetails(
        topic_id=topic_ocid,
        protocol="EMAIL",
        endpoint=ALERT_EMAIL
    )
    sub = ons_client.create_subscription(create_sub_details).data
    print(f"Created subscription: {sub.id}")
    print("Check your email and CONFIRM the subscription link from OCI.")
    return sub


def create_nsg_events_rule_if_not_exists(topic_ocid):
    rules = oci.pagination.list_call_get_all_results(
        events_client.list_rules,
        compartment_id=COMPARTMENT_OCID
    ).data

    for r in rules:
        if r.display_name == RULE_DISPLAY_NAME:
            print(f"Events rule already exists: {r.id}")
            return r

    condition = {
        "eventType": [
            "com.oraclecloud.virtualnetwork.create.networksecuritygroup",
            "com.oraclecloud.virtualnetwork.update.networksecuritygroup",
            "com.oraclecloud.virtualnetwork.delete.networksecuritygroup"
        ]
    }

    # Define the action to send events to the topic
    ons_target = oci.events.models.CreateStreamingServiceActionDetails(
        # NOTE: For Notifications, use CreateNotificationServiceActionDetails in newer SDKs.
        # Some older SDKs may require a different class; adjust as per your oci version.
    )

    # Correct action for Notifications:
    ons_action = oci.events.models.CreateNotificationServiceActionDetails(
        action_type="ONS",
        is_enabled=True,
        topic_id=topic_ocid
    )

    create_rule_details = oci.events.models.CreateRuleDetails(
        display_name=RULE_DISPLAY_NAME,
        description=RULE_DESCRIPTION,
        is_enabled=True,
        compartment_id=COMPARTMENT_OCID,
        condition=condition,
        actions=oci.events.models.ActionDetailsList(
            actions=[ons_action]
        )
    )

    rule = events_client.create_rule(create_rule_details).data
    print(f"Created NSG events rule: {rule.id}")
    return rule


def main():
    topic = create_topic_if_not_exists()
    create_email_subscription_if_not_exists(topic.topic_id)
    # Wait a bit to avoid race conditions in very fresh tenancy setups
    time.sleep(5)
    create_nsg_events_rule_if_not_exists(topic.topic_id)


if __name__ == "__main__":
    main()

Notes:

Ensure your SDK version supports CreateNotificationServiceActionDetails. If not, update:
pip install --upgrade oci
After running the script, confirm the email subscription from your inbox.
From then on, any NSG create/update/delete in the compartment will trigger an email alert.

If you want, I can adapt this to:

Use a specific dynamic group/policy setup,
Target a different protocol (Slack via HTTPS, PagerDuty, etc.),
Or wire an OCI Function instead of direct email.

Using Terraform

resource "oci_events_rule" "nsg_change_events" {
  # Substitute with your compartment OCID
  compartment_id = "OCID_OF_TARGET_COMPARTMENT"

  display_name = "nsg-change-events"
  description  = "Trigger notifications when Network Security Groups are created, updated, deleted, or moved."

  is_enabled = true

  # Event rule condition to match NSG changes
  # Adjust 'id' if you want to scope only to specific NSGs.
  condition = <<EOF
{
  "eventType": [
    "com.oraclecloud.virtualnetwork.createnetworksecuritygroup",
    "com.oraclecloud.virtualnetwork.updatenetworksecuritygroup",
    "com.oraclecloud.virtualnetwork.deletenetworksecuritygroup",
    "com.oraclecloud.virtualnetwork.changenetworksecuritygroupcompartment"
  ],
  "data": {
    "resourceName": [
      "networksecuritygroups"
    ]
  }
}
EOF

  actions {
    actions {
      # Send an alert via OCI Notifications
      action_type = "ONS"
      is_enabled  = true

      # Substitute with your Notifications topic OCID
      topic_id = "OCID_OF_OCI_NOTIFICATIONS_TOPIC"

      description = "Notify on Network Security Group configuration changes"
    }
  }

  freeform_tags = {
    "OWNER" = "TEAM_NAME_OR_OWNER"
  }
}

This change is in-place for an existing oci_events_rule (no forced replacement unless you change compartment_id to a different compartment or switch to a new rule resource entirely).Verification: terraform plan should show either a new oci_events_rule.nsg_change_events being created or the existing rule updated so that:

is_enabled is true
condition matches the NSG event types
actions[0].action_type is ONS with the desired topic_id.

OCI Misconfigurations

OCI Monitoring Should Have Event Rule For NSG Changes

More Info:

Risk Level

Address

Compliance Standards

Triage and Remediation

Remediation

1. Prerequisites

2. Create (or Reuse) a Notifications Topic

3. Create the Event Rule for NSG Changes

3.1. Basic Rule Details

3.2. Define the Event Pattern

4. Attach an Action to Send Alerts

5. (Optional) Centralize or Enhance Monitoring

6. Test the Configuration

1. Prereqs

2. Create a Notifications topic

3. Create a subscription on the topic (e.g., email)

4. Create the Events rule for NSG changes

5. Test

1. What you will create

2. Prerequisites

3. Event Types for NSG Changes

4. Full Python Example

​More Info:

​Risk Level

​Address

​Compliance Standards

​Triage and Remediation

​Remediation

​1. Prerequisites

​2. Create (or Reuse) a Notifications Topic

​Add a Subscription (Email / Pager / etc.)

​3. Create the Event Rule for NSG Changes

​3.1. Basic Rule Details

​3.2. Define the Event Pattern

​4. Attach an Action to Send Alerts

​5. (Optional) Centralize or Enhance Monitoring

​6. Test the Configuration

​1. Prereqs

​2. Create a Notifications topic

​3. Create a subscription on the topic (e.g., email)

​4. Create the Events rule for NSG changes

​5. Test

​1. What you will create

​2. Prerequisites

​3. Event Types for NSG Changes

​4. Full Python Example

More Info:

Risk Level

Address

Compliance Standards

Triage and Remediation

Remediation

1. Prerequisites

2. Create (or Reuse) a Notifications Topic

Add a Subscription (Email / Pager / etc.)

3. Create the Event Rule for NSG Changes

3.1. Basic Rule Details

3.2. Define the Event Pattern

4. Attach an Action to Send Alerts

5. (Optional) Centralize or Enhance Monitoring

6. Test the Configuration

1. Prereqs

2. Create a Notifications topic

3. Create a subscription on the topic (e.g., email)

4. Create the Events rule for NSG changes

5. Test

1. What you will create

2. Prerequisites

3. Event Types for NSG Changes

4. Full Python Example