diff --git a/terraform/dos.tf b/terraform/dos.tf
new file mode 100644
index 000000000..626b8e0e1
--- /dev/null
+++ b/terraform/dos.tf
@@ -0,0 +1,117 @@
+# Copyright 2020 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This file contains the Cloud Armor configs.
+
+resource "google_compute_security_policy" "cloud-armor" {
+  name = "cloud-armor-protection"
+  rule {
+    action      = "deny(403)"
+    description = "XSS protection"
+    match {
+      expr { expression = "evaluatePreconfiguredExpr('xss-stable')" }
+    }
+    preview  = false
+    priority = 10
+  }
+  rule {
+    action      = "deny(403)"
+    description = "SQL Injection protection"
+    match {
+      expr { expression = "evaluatePreconfiguredExpr('sqli-stable')" }
+    }
+    preview  = false
+    priority = 20
+  }
+  rule {
+    action      = "deny(403)"
+    description = "Remote Code Execution protection"
+    match {
+      expr { expression = "evaluatePreconfiguredExpr('rce-stable')" }
+    }
+    preview  = false
+    priority = 30
+  }
+  // Recommended action when we want to protect the service during incident:
+  // 1. See if there's any rule below can be used as is. Use that.
+  // 2. Otherwise check
+  //    https://cloud.google.com/armor/docs/rules-language-reference and see if
+  //    there's other attributes that you can use.
+  // 3. Run `terraform apply` with "preview=true" first.
+  // 4. Go to "Monitoring - Dashboards" and choose "Network Security Policies".
+  //    Check the "Previewd Requests" graph at the bottom and see how many
+  //    traffic would be blocked if "preview=false". Ensure the rule doesn't
+  //    block all traffic by accident. If it does block too many traffics, go
+  //    back and review the expression.
+  // 5. Run `terraform apply` again with "preview=false".
+  //
+  // Block certain User-Agent
+  // ========================
+  // rule {
+  //   action      = "deny(403)"
+  //   description = "Block User-Agent FOO"
+  //   match {
+  //     expr {
+  //       expression = <<-EOT
+  //         has(request.headers['user-agent']) &&
+  //         request.headers.['user-agent'].matches('FOO')
+  //       EOT
+  //     }
+  //   }
+  //   preview  = true
+  //   priority = 40
+  // }
+  //
+  // Block IP ranges
+  // ===============
+  // rule {
+  //   action      = "deny(403)"
+  //   description = "Block IP Range FOO"
+  //   match {
+  //     expr {
+  //       expression = <<-EOT
+  //         inIPRange(origin.ip, '1.2.3.0/24')
+  //       EOT
+  //     }
+  //   }
+  //   preview  = true
+  //   priority = 50
+  // }
+  //
+  // Block access to a certain URL path
+  // ==================================
+  // rule {
+  //   action      = "deny(403)"
+  //   description = "Block path FOO"
+  //   match {
+  //     expr {
+  //       expression = <<-EOT
+  //         request.path.matches('FOO')
+  //       EOT
+  //     }
+  //   }
+  //   preview  = true
+  //   priority = 50
+  // }
+  rule {
+    action      = "allow"
+    description = "Default rule, higher priority overrides it"
+    match {
+      config { src_ip_ranges = ["*"] }
+      versioned_expr = "SRC_IPS_V1"
+    }
+    preview  = false
+    priority = 2147483647
+  }
+}
diff --git a/terraform/service_debugger.tf b/terraform/service_debugger.tf
index 65ac47460..dc34a170a 100644
--- a/terraform/service_debugger.tf
+++ b/terraform/service_debugger.tf
@@ -164,6 +164,7 @@ resource "google_compute_backend_service" "debugger" {
   backend {
     group = google_compute_region_network_endpoint_group.debugger[0].id
   }
+  security_policy = google_compute_security_policy.cloud-armor.name
 }
 
 output "debugger_urls" {
diff --git a/terraform/service_exposure.tf b/terraform/service_exposure.tf
index 70932cabc..54ebf8631 100644
--- a/terraform/service_exposure.tf
+++ b/terraform/service_exposure.tf
@@ -170,6 +170,7 @@ resource "google_compute_backend_service" "exposure" {
   backend {
     group = google_compute_region_network_endpoint_group.exposure[0].id
   }
+  security_policy = google_compute_security_policy.cloud-armor.name
 }
 
 output "exposure_urls" {
diff --git a/terraform/service_federationout.tf b/terraform/service_federationout.tf
index aafeb22e2..f5e846228 100644
--- a/terraform/service_federationout.tf
+++ b/terraform/service_federationout.tf
@@ -154,6 +154,7 @@ resource "google_compute_backend_service" "federationout" {
   backend {
     group = google_compute_region_network_endpoint_group.federationout[0].id
   }
+  security_policy = google_compute_security_policy.cloud-armor.name
 }
 
 output "federationout_urls" {