> ## Documentation Index > Fetch the complete documentation index at: https://gcore-doc-1046.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Create a CDN rule via Terraform If a CDN resource was created via Terraform, you can [add a rule](/cdn/cdn-resource-options/rules-for-particular-files/create-a-rule-manually-or-from-a-template-to-configure-settings-for-particular-files) to it via Terraform. To do this, use the following instructions. 1\. Open the *main.tf* file. 2\. The file is supposed to contain the code for the creation of your CDN resource. If it is missing, add the code according to the [Create a new CDN resource](/cdn/terraform/manage-a-cdn-resource-with-terraform#create-a-new-cdn-resource) section. Don't worry, Terraform won't duplicate a resource. Terraform requires the code used to create a resource only to identify a resource that should be changed. 3\. At this step, you will add the necessary strings for creating a rule to the configuration file. Add the code below to a new string. Replace the hints in the brackets with your values and remove the brackets. ``` resource "gcore_cdn_rule" "make up Terraform name for the rule; you can use any name, it will be linked to the rule inside the Terraform system" { resource_id = gcore_cdn_resource.Terraform name of the CDN resource for which you are adding the rule.id name = "make up a name for the rule that will be displayed in the Gcore Customer Portal" rule = "specify path to the files for which you are adding the rule; the path should always start with "^/" or "/"" rule_type = 0 ``` 4\. If you want to add options to the rule, paste the code below. Replace the hints in the brackets with your values and remove the brackets. ``` options { code to configure the necessary options; for set-up guides, refer to the Terraform documentation for the Gcore provider, an example of configuration can be found in the "Configure CDN resource options" section } ``` If you don't need options, do not add the *options* code segment. 5\. Be aware to add a curly bracket to a new string below. ``` } ``` Here is an example of a configuration file. Let's say you want to add a rule with the following characteristics: * example\_rule — the name of the rule for Terraform * cdn\_example\_com — the name of the CDN resource in Terraform * PNG images — the name of the rule from the Gcore Customer Portal * /folder/images/\*.png — the path to the files * The "WebP Compression" option with a final quality of 66 is required The final code in the configuration file will look as follows: configuration file 6\. Save the changes in the configuration file. 7\. Access the "Terraform" folder in the command-line interface unless you are already in it, and run the `terraform plan` command — it will show what changes Terraform is going to make. If the code contains an error, the output will give a brief description of it. 8\. Run the `terraform apply` command — it will make changes to the CDN. Terraform will ask you to confirm the action — enter "yes".