Validate a parameter value with the AllowedPattern property

The AllowedPattern property in an Azure Resource Manager (ARM) and CloudFormation (CF) template performs input validation before sending a provisioning request.

Avant de commencer

Role required: sn.cmp.cloud_service_designer

Pourquoi et quand exécuter cette tâche

You can provide rules to validate a parameter value before sending the provisioning request to the cloud. To be notified with an error message if the validation fails, specify the ConstraintDescription property in the template. You can customize the error message in the ConstraintDescription property to make the message clear and explicit. Usually, the CF templates already have the AllowedPattern and ConstraintDescription properties. If these properties are not present, you can add them as mentioned in the following procedure:

Procédure

1. In the Cloud Admin Portal, navigate to Design > Cloud Templates.
2. Select a template or click New to create a new cloud template.
   If you select an existing template, rename the template.
3. In the Body text box, make the following changes in an ARM and a CF template.
   1. In an ARM template, make these changes:
      • In the parameters metadata section, enter SNC::Parameter::Metadata.
      • Add the AllowedPattern key and enter a valid value range.
      • Add the ConstraintDescription key and enter an error message.

      "parameters": {
               "newStorageAccountName": {
                   "type": "string",
                    "metadata": {
                        "description": "Unique DNS Name for the Storage Account where the Virtual Machine's disks will be placed.",
                         "SNC::Parameter::Metadata": {
                             "allowedPattern": "[0-9a-z]{1,11}",
                              "ConstraintDescription": "must be an alphanumeric "
                                                    
                                 }}} 
             
          
      

   2. In a CF template, make these changes:
      • Add the AllowedPattern key and enter a valid value range.
      • Add the ConstraintDescription key and enter an error message.

      "Parameters" : {
                      "SSHLocation" : {
                      "Description" : "The IP address range that can be used to SSH to the EC2 instances",
                      "Type": "String",
                      "MinLength": "9",
                      "MaxLength": "18",
                      "Default": "0.0.0.0/0",
                       "AllowedPattern": "(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})\\.(\\d{1,3})/(\\d{1,2})",
                       "ConstraintDescription": "must be a valid IP CIDR range of the form x.x.x.x/x."
      
          } 
        }

4. Click Submit.