The “Internet Gateway Changes Alarm” indicates that changes have been made to the internet gateway in your AWS environment. To remediate this issue using AWS CLI, follow these steps:

1. Open the AWS CLI on your local machine.

2. Run the following command to describe the internet gateways in your AWS environment:

aws ec2 describe-internet-gateways

3. Identify the internet gateway that has been changed by comparing the output of the above command with the previous state of your environment.

4. Run the following command to delete the internet gateway:

aws ec2 delete-internet-gateway --internet-gateway-id `<internet_gateway_id>`

Note: Replace <internet_gateway_id> with the ID of the internet gateway that has been changed.

5. If the internet gateway was deleted by mistake, run the following command to create a new internet gateway:

aws ec2 create-internet-gateway

6. Attach the new internet gateway to your VPC using the following command:

aws ec2 attach-internet-gateway --internet-gateway-id <new_internet_gateway_id> --vpc-id <vpc_id>

Note: Replace <new_internet_gateway_id> with the ID of the new internet gateway that was created and <vpc_id> with the ID of your VPC.

7. Verify that the internet gateway has been remediated by running the describe-internet-gateways command again and checking that the internet gateway is attached to your VPC.

The misconfiguration “Internet Gateway Changes Alarm” in AWS can occur when there is a change in the Internet Gateway associated with the VPC. To remediate this, you can follow these steps using Python:

1. Import the necessary modules and define the AWS client:

import boto3
client = boto3.client('cloudwatch')

2. Define the name of the alarm that needs to be remediated:

alarm_name = 'InternetGatewayChangesAlarm'

3. Get the alarm details using the describe_alarms() method:

response = client.describe_alarms(
    AlarmNames=[alarm_name]
)

4. Check if the alarm exists and has the correct action:

if len(response['MetricAlarms']) == 0:
    print(f"The alarm {alarm_name} does not exist.")
elif response['MetricAlarms'][0]['AlarmActions'] == []:
    print(f"The alarm {alarm_name} has no actions.")
else:
    print(f"The alarm {alarm_name} has actions.")

5. If the alarm exists and has no actions, add the necessary action using the put_metric_alarm() method:

response = client.put_metric_alarm(
    AlarmName=alarm_name,
    AlarmActions=['arn:aws:sns:us-east-1:123456789012:MyTopic'],
    MetricName='InternetGatewayAttached',
    Namespace='AWS/EC2',
    Statistic='Sum',
    Dimensions=[
        {
            'Name': 'VpcId',
            'Value': 'vpc-12345678'
        },
    ],
    Period=300,
    EvaluationPeriods=1,
    Threshold=1,
    ComparisonOperator='GreaterThanOrEqualToThreshold',
    TreatMissingData='notBreaching'
)

Note: Replace the AlarmActions value with the ARN of the SNS topic that needs to be notified.

6. Verify that the action has been added:

response = client.describe_alarms(
    AlarmNames=[alarm_name]
)

if response['MetricAlarms'][0]['AlarmActions'] == []:
    print(f"The alarm {alarm_name} still has no actions.")
else:
    print(f"The alarm {alarm_name} now has actions.")

7. If the action was successfully added, print a success message:

print(f"The alarm {alarm_name} has been remediated.")

This Python script will add an SNS topic as the action for the “Internet Gateway Changes Alarm” in AWS.