This assumes you have already configured the aws command line tool. If not, check out my article on Getting Started with the AWS CLI.

Cloudwatch alarms can be used to alert you when some conditiion is met, such as if an EC2 instance is unavailable due to high CPU or high memory usage.

The aws cloudwatch describe-alarms command can be used to list the cloudwatch alarms you have created.

aws cloudwatch describe-alarms

If one of more cloudwatch alarms have been created, something like this should be returned.

{
    "MetricAlarms": [
        {
            "AlarmName": "high-cpu",
            "AlarmArn": "arn:aws:cloudwatch:us-east-1:713123474299:alarm:high-cpu",
            "AlarmDescription": "Alarm when CPU exceeds 70 percent",
            "AlarmConfigurationUpdatedTimestamp": "2023-06-21T01:53:16.629000+00:00",
            "ActionsEnabled": true,
            "OKActions": [],
            "AlarmActions": [
                "arn:aws:sns:us-east-1:713123474299:my-topic"
            ],
            "InsufficientDataActions": [],
            "StateValue": "OK",
            "StateReason": "Threshold Crossed: 2 datapoints [1.3967213114600159 (21/06/23 01:44:00), 1.234648513479913 (21/06/23 01:39:00)] were not greater than the threshold (70.0).",
            "StateReasonData": "{\"version\":\"1.0\",\"queryDate\":\"2023-06-21T01:54:00.142+0000\",\"startDate\":\"2023-06-21T01:39:00.000+0000\",\"unit\":\"Percent\",\"statistic\":\"Average\",\"period\":300,\"recentDatapoints\":[1.234648513479913,1.3967213114600159],\"threshold\":70.0,\"evaluatedDatapoints\":[{\"timestamp\":\"2023-06-21T01:44:00.000+0000\",\"sampleCount\":5.0,\"value\":1.3967213114600159}]}",
            "StateUpdatedTimestamp": "2023-06-21T01:54:00.144000+00:00",
            "MetricName": "CPUUtilization",
            "Namespace": "AWS/EC2",
            "Statistic": "Average",
            "Dimensions": [
                {
                    "Name": "InstanceId",
                    "Value": "i-0d241234f9665abcd"
                }
            ],
            "Period": 300,
            "Unit": "Percent",
            "EvaluationPeriods": 2,
            "Threshold": 70.0,
            "ComparisonOperator": "GreaterThanThreshold"
        }
    ],
    "CompositeAlarms": []
}

The aws cloudwatch delete-alarms command can be used to delete one or more cloudwatch alarms.

aws cloudwatch delete-alarms --alarm-names high-cpu