Using condition keys to limit access to CloudWatch namespaces

Use IAM condition keys to limit users to publishing metrics only in the CloudWatch namespaces that you specify.

Allowing publishing in one namespace only

The following policy limits the user to publishing metrics only in the namespace named MyCustomNamespace.

{
    "Version": "2012-10-17",
    "Statement": {
        "Effect": "Allow",
        "Resource": "*",
        "Action": "cloudwatch:PutMetricData",
        "Condition": {
            "StringEquals": {
                "cloudwatch:namespace": "MyCustomNamespace"
            }
        }
    }
}

Excluding publishing from a namespace

The following policy allows the user to publish metrics in any namespace except for CustomNamespace2.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Resource": "*",
            "Action": "cloudwatch:PutMetricData"
        },
        {
            "Effect": "Deny",
            "Resource": "*",
            "Action": "cloudwatch:PutMetricData",
            "Condition": {
                "StringEquals": {
                    "cloudwatch:namespace": "CustomNamespace2"
                }
            }
        }
    ]
}