Configuring WAF rule sets

With Terraform, you can quickly create a cloud infrastructure in Yandex Cloud and manage it using configuration files. These files store the infrastructure description written in HashiCorp Configuration Language (HCL). If you change the configuration files, Terraform automatically detects which part of your configuration is already deployed, and what should be added or removed.

Terraform is distributed under the Business Source License. The Yandex Cloud provider for Terraform is distributed under the MPL-2.0 license.

For more information about the provider resources, see the relevant documentation on the Terraform website or its mirror.

If you do not have Terraform yet, install it and configure the Yandex Cloud provider.

You can dynamically enable all rules in the basic set if their paranoia level is not higher than the value defined in the user variable. You can manually edit the settings of dynamically configured rules. For example, you can turn a rule into a blocking one and enable a rule with the paranoia level higher than the one defined in the variable.

1. Open the Terraform configuration file and edit the yandex_sws_waf_profile description: add either the rule section with a security rule or the dynamic "rule" section with dynamically configured rules.

   # In the basic set, rules of this paranoia level and below will be enabled
   locals {
     waf_paranoia_level = 1
   }
   
   # OWASP Core Rule Set data source
   data "yandex_sws_waf_rule_set_descriptor" "owasp4" {
     name    = "OWASP Core Ruleset"
     version = "4.0.0"
   }
   
   # WAF profile
   resource "yandex_sws_waf_profile" "default" {
     name = "<WAF_profile_name>"
   
     # Basic rule set
     core_rule_set {
       inbound_anomaly_score = 2
       paranoia_level        = local.waf_paranoia_level
       rule_set {
         name    = "OWASP Core Ruleset"
         version = "4.0.0"
       }
     }
   
     # Turning the rule into a blocking one: the request will be blocked regardless of the anomaly threshold
     rule {
       rule_id     = "owasp-crs-v4.0.0-id942330-attack-sqli"
       is_enabled  = true
       is_blocking = true
     }
   
     # Enabling the rule with paranoia level 4
     rule {
       rule_id     = "owasp-crs-v4.0.0-id920202-protocol-enforcement"
       is_enabled  = true
       is_blocking = false
     }
   
     # Enabling rules from the basic set if their paranoia level is not higher than the value defined in the waf_paranoia_level variable
     dynamic "rule" {
       for_each = [
         for rule in data.yandex_sws_waf_rule_set_descriptor.owasp4.rules : rule
         if rule.paranoia_level <= local.waf_paranoia_level
       ]
       content {
         rule_id     = rule.value.id
         is_enabled  = true
         is_blocking = false
       }
     }
   
     analyze_request_body {
       is_enabled        = true
       size_limit        = 8
       size_limit_action = "IGNORE"
     }
   }
   

   Where:

   • dynamic "rule": Dynamically enabling the rules in the basic set if their paranoia level is not higher than the value defined in the waf_paranoia_level variable. You can manually edit the settings of dynamically configured rules. For example, you can turn a rule into a blocking one or enable a rule with the paranoia level higher than the one defined in the variable.
     • rule_id: Rule ID.
     • is_enabled: Flag to enable or disable a rule.
     • is_blocking: Blocking rule flag.

   For more information about sws_waf_profile properties, see this Terraform provider article.

2. Create the resources:

   1. In the terminal, go to the directory where you edited the configuration file.

   2. Make sure the configuration file is correct using this command:

      terraform validate
      

      If the configuration is correct, you will get this message:

      Success! The configuration is valid.
      

   3. Run this command:

      terraform plan
      

      You will see a detailed list of resources. No changes will be made at this step. If the configuration contains any errors, Terraform will show them.

   4. Apply the changes:

      terraform apply
      

   5. Type yes and press Enter to confirm the changes.

You can check the resource update in the management console.

Use the update REST API method for the WafProfile resource or the WafProfile/Update gRPC API call.