Aws Iot create rule error while creating new rule
<p>I am creating a new rule using the following command </p>

<pre><code>aws iot create-topic-rule --rule-name my-rule --topic-rule-payload file://myrule.json
</code></pre>

<p>The content of <code>myrule.json</code> contents is </p>

<pre><code>{
  "sql": "SELECT * FROM 'iot/test'",
  "ruleDisabled": false,
  "awsIotSqlVersion": "2016-03-23-beta",
  "actions": [{
      "dynamoDB": {
          "tableName": "my-dynamodb-table",
          "roleArn": "arn:aws:iam::12345*****:role/my-iot-role",
          "hashKeyField": "topic",
          "hashKeyValue": "${topic(2)}",
          "rangeKeyField": "timestamp",
          "rangeKeyValue": "${timestamp()}"
      }
  }]
}
</code></pre>

<p>I am getting following error.</p>

<blockquote>
  <p>A client error (InvalidRequestException) occurred when calling the
  CreateTopicRule operation: 1 validation error detected: Value
  'my-rule' at 'ruleName' failed to satisfy constraint: Member must
  satisfy regular expression pattern: ^[a-zA-Z0-9_]+$</p>
</blockquote>

<p>please can someone help?</p>