1. Create a VM Compute instance using the Datadog AAP Service Extensions Docker image.

   See Configuration for available environment variables when setting up your VM instance.

   Note: Be sure to update your Firewall rules to allow the Load Balancer and Datadog agent to communicate with the Callout VM instance.

2. Add the VM to an unmanaged instance group.

   Specify http:80 and grpc:443 (or your configured values) for the port mappings of the instance group.

3. Create a backend service with the following settings:

   • Protocol: HTTP2
   • Port name: grpc
   • Region: select your region
   • Health check port number: 80 (or your configured value)

4. Add the instance group with the service extension VM as a backend to this backend service.

5. Configure the Traffic Service Extension callout:

   1. In the Google Cloud console, go to Service Extensions and create a new Service Extension.
   2. Select your load balancer type.
   3. Select Traffic extensions as the type.
   4. Select your forwarding rules.
      
      

6. Create an Extension Chain

   1. To send all traffic to the extension, insert true in the Match condition.
   2. For Programability type, select Callouts.
   3. Select the backend service you created in the previous step.
   4. Select all Events from the list where you want AAP to run detection (Request Headers and Response Headers are required).

After this configuration is complete, the library collects security data from your application and sends it to the Agent. The Agent sends the data to Datadog, where out-of-the-box detection rules flag attacker techniques and potential misconfigurations so you can take steps to remediate.

1. To see App and API Protection threat detection in action, send known attack patterns to your application. For example, trigger the Security Scanner Detected rule by running a file that contains the following curl script:

   for ((i=1;i<=250;i++)); 
   do
   # Target existing service's routes
   curl https://your-application-url/existing-route -A dd-test-scanner-log;
   # Target non existing service's routes
   curl https://your-application-url/non-existing-route -A dd-test-scanner-log;
   done

   Note: The dd-test-scanner-log value is supported in the most recent releases.

   A few minutes after you enable your application and send known attack patterns to it, threat information appears in the Application Signals Explorer and vulnerability information appears in the Vulnerabilities explorer.

You can use Terraform to automate the deployment of the AAP GCP Service Extension. This simplifies the process of setting up the service extension to work with your existing load balancer.

Prerequisites for Terraform deployment

• Terraform installed on your local machine (version 1.0.0 or later)
• GCP credentials with appropriate permissions
• A Datadog API key (used to configure the Datadog Agent)
• An existing GCP Cloud Load Balancer for your application

Infrastructure Overview

The Terraform deployment will create the following components:

• A Datadog Agent VM for collecting traces with security events
• A VM running the Datadog Service Extension Callout in a container
• A firewall rule allowing communication between the extension and the Agent
• An unmanaged instance group containing the Service Extension VM
• A backend service configured for HTTP/2 with health checks
• A service extension connected to your existing load balancer

Deployment Steps

The AAP Service Extension deployment requires several components that work together. We’ll create a Terraform module that encapsulates all these components, making the deployment process repeatable and easier to maintain.

1. Create a new directory and the necessary Terraform files:

   mkdir gcp-aap-service-extension && cd gcp-aap-service-extension
   touch main.tf variables.tf
   

2. Add the following code to your main.tf file. This file defines all the infrastructure components needed for the AAP Service Extension, including network rules, VM instances, and load balancer configuration:

   # main.tf
   
   #----------------------------------------------------------
   # Network Configuration
   #----------------------------------------------------------
   
   # Firewall rule to allow the Service Extension to communicate with the Datadog Agent
   resource "google_compute_firewall" "aap_se_firewall" {
     name    = "${var.project_prefix}-dd-agent-firewall"
     network = "default"
   
     allow {
       protocol = "tcp"
       ports    = ["8126"]
     }
   
     source_tags = ["http-server"]
     target_tags = ["datadog-agent"]
   }
   
   #----------------------------------------------------------
   # Datadog Agent Configuration
   #----------------------------------------------------------
   
   # Datadog Agent container configuration
   module "gce-container-datadog-agent" {
     source = "terraform-google-modules/container-vm/google"
   
     container = {
       image = "public.ecr.aws/datadog/agent:latest"
       env = [
         {
           name = "DD_API_KEY",
           value = var.datadog_agent_api_key,
         },
         {
           name = "DD_ENV",
           value = "dev",
         },
       ]
     }
   }
   
   # Datadog Agent VM instance that collects traces from the Service Extension
   resource "google_compute_instance" "datadog_agent" {
     name         = "${var.project_prefix}-datadog-agent"
     machine_type = "e2-medium"
     zone         = var.zone
   
     boot_disk {
       auto_delete = true
   
       initialize_params {
         image = module.gce-container-datadog-agent.source_image
       }
   
     }
   
     network_interface {
       network    = "default"
       subnetwork = var.application_vpc_subnetwork
     }
   
     metadata = {
       gce-container-declaration = module.gce-container-datadog-agent.metadata_value
       google-logging-enabled    = "true"
     }
   
     lifecycle {
       create_before_destroy = true
     }
   
     tags = ["datadog-agent"]
   }
   
   #----------------------------------------------------------
   # Service Extension Callout Container Configuration
   #----------------------------------------------------------
   
   # Datadog AAP GCP Service Extension container configuration
   module "gce-container-aap-service-extension" {
     source = "terraform-google-modules/container-vm/google"
   
     container = {
       image = "ghcr.io/datadog/dd-trace-go/service-extensions-callout:v1.72.1" # Replace with the latest version
       env = [
         {
           name = "DD_AGENT_HOST",
           value = google_compute_instance.datadog_agent.network_interface.0.network_ip,
         }
       ]
     }
   }
   
   # Service Extension VM instance (callout instance)
   resource "google_compute_instance" "default" {
     name         = "${var.project_prefix}-instance"
     machine_type = "e2-medium"
     zone         = var.zone
   
     boot_disk {
       auto_delete = true
   
       initialize_params {
         image = module.gce-container-aap-service-extension.source_image
       }
   
     }
   
     network_interface {
       network    = var.application_vpc_network
       subnetwork = var.application_vpc_subnetwork
     }
   
     metadata = {
       gce-container-declaration = module.gce-container-aap-service-extension.metadata_value
       google-logging-enabled    = "true"
     }
   
     lifecycle {
       create_before_destroy = true
     }
   
     # http-server: Allow access on the http server for health checks
     # https-server: Allow access on the 443 port for the AAP Service Extension
     tags = ["http-server", "https-server", "lb-health-check"]
   }
   
   #----------------------------------------------------------
   # Load Balancer Integration
   #----------------------------------------------------------
   
   # Unmanaged Instance Group including the AAP Service Extension instance
   resource "google_compute_instance_group" "aap_se_instance_group" {
     name        = "${var.project_prefix}-instance-group"
     description = "Unmanaged instance group for the AAP Service Extension"
     zone        = var.zone
   
     named_port {
       name = "http"
       port = 80
     }
   
     named_port {
       name = "grpc"
       port = "443"
     }
   
     instances = [
       google_compute_instance.default.self_link
     ]
   }
   
   # Health Check for the Backend Service
   resource "google_compute_health_check" "aap_se_health_check" {
     name                = "${var.project_prefix}-health-check"
     check_interval_sec  = 5
     timeout_sec         = 5
     healthy_threshold   = 2
     unhealthy_threshold = 2
   
     http_health_check {
       port         = 80
       request_path = "/"
     }
   }
   
   # Backend Service that points to the Service Extension instance group
   resource "google_compute_backend_service" "se_backend_service" {
     name                  = "${var.project_prefix}-backend-service"
     port_name             = "grpc"
     protocol              = "HTTP2"
     timeout_sec           = 10
     health_checks         = [google_compute_health_check.aap_se_health_check.self_link]
     load_balancing_scheme = "EXTERNAL_MANAGED"
   
     backend {
       group = google_compute_instance_group.aap_se_instance_group.self_link
     }
   }
   
   #----------------------------------------------------------
   # GCP Service Extension
   #----------------------------------------------------------
   
   # GCP Service Extension configuration for traffic interception
   resource "google_network_services_lb_traffic_extension" "default" {
     name        = "${var.project_prefix}-service-extension"
     description = "Datadog AAP Service Extension"
     location    = "global"
   
     load_balancing_scheme = "EXTERNAL_MANAGED"
     forwarding_rules      = [var.load_balancer_forwarding_rule]
   
     extension_chains {
       name = "${var.project_prefix}-service-extension-chain"
   
       match_condition {
         cel_expression = "true" # Match all traffic
       }
   
       extensions {
         name      = "${var.project_prefix}-service-extension-chain-ext"
         authority = "datadoghq.com"
         service   = google_compute_backend_service.se_backend_service.self_link
         timeout   = "0.5s"
         fail_open = false # If the extension fails, the request is dropped
   
         # Supported events for the AAP Service Extension
         supported_events = ["REQUEST_HEADERS", "REQUEST_BODY", "RESPONSE_HEADERS", "RESPONSE_BODY"]
       }
     }
   }
   

3. Add the following content to the variables.tf file. This file defines all the required input variables for your Terraform configuration:

   # variables.tf
   
   variable "region" {
     description = "The GCP region where resources will be created (e.g., us-central1)"
     type        = string
     validation {
       condition     = length(var.region) > 0
       error_message = "Region cannot be empty."
     }
   }
   
   variable "zone" {
     description = "The GCP zone where zonal resources will be created (e.g., us-central1-a)"
     type        = string
     validation {
       condition     = length(var.zone) > 0
       error_message = "Zone cannot be empty."
     }
   }
   
   # Project configuration
   variable "project_prefix" {
     description = "Prefix for the project. All resource names will be prefixed with this value"
     type        = string
     validation {
       condition     = length(var.project_prefix) > 0
       error_message = "Project prefix cannot be empty."
     }
   }
   
   # Network configuration
   variable "application_vpc_network" {
   
     description = "Name of the VPC network for the application"
     type        = string
     validation {
       condition     = length(var.application_vpc_network) > 0
       error_message = "VPC network name cannot be empty."
     }
   }
   
   variable "application_vpc_subnetwork" {
   
     description = "Name of the VPC subnetwork for the application"
     type        = string
     validation {
       condition     = length(var.application_vpc_subnetwork) > 0
       error_message = "VPC subnetwork name cannot be empty."
     }
   }
   
   # Authentication and API keys
   variable "datadog_agent_api_key" {
     description = "Datadog API key"
     type        = string
     sensitive   = true
     validation {
       condition     = length(var.datadog_agent_api_key) > 0
       error_message = "Datadog API key cannot be empty."
     }
   }
   
   # Load balancer configuration
   variable "load_balancer_forwarding_rule" {
     description = "Self link to the forwarding rule for the load balancer"
   }
   

4. Include the module in your main Terraform project. This example shows how to reference the module you created above:

   # main.tf
   
   module "service_extension" {
     source                        = "./gcp-aap-service-extension"
     zone                          = "us-central1-a"
     region                        = "us-central1"
     project_prefix                = "datadog-aap"
     application_vpc_subnetwork    = "your-subnet-name"
     datadog_agent_api_key         = "your-datadog-api-key"
     load_balancer_forwarding_rule = "projects/your-project/regions/us-central1/forwardingRules/your-lb-rule" # or with a self link on your resource
   }
   

5. Deploy the infrastructure by running these commands in the directory where your Terraform files are located:

   terraform init
   terraform plan
   terraform apply
   

Post-deployment validation

The service extension automatically inspects all traffic passing through your load balancer for security threats.

After this configuration is complete, the library collects security data from your application and sends it to the Agent. The Agent sends the data to Datadog, where out-of-the-box detection rules flag attacker techniques and potential misconfigurations so you can take steps to remediate.

1. To see App and API Protection threat detection in action, send known attack patterns to your application. For example, trigger the Security Scanner Detected rule by running a file that contains the following curl script:

   for ((i=1;i<=250;i++)); 
   do
   # Target existing service's routes
   curl https://your-application-url/existing-route -A dd-test-scanner-log;
   # Target non existing service's routes
   curl https://your-application-url/non-existing-route -A dd-test-scanner-log;
   done

   Note: The dd-test-scanner-log value is supported in the most recent releases.

   A few minutes after you enable your application and send known attack patterns to it, threat information appears in the Application Signals Explorer and vulnerability information appears in the Vulnerabilities explorer.