feat: default allow all users to use default psp

adjusts examples and mention psp binding

README.md

@@ -4,7 +4,7 @@
 
 ![terraform](https://github.com/goci-io/k8s-namespace-provisioning/workflows/terraform/badge.svg?branch=master)
 
-This terraform module provisions a ready to use namespace with docker registry secrets, resource quotas, limits and a service account with limited rbac permissions.
+This terraform module provisions a ready to use namespace with docker registry secrets, resource quotas and limits. Additionally it allows everyone in the namespace to use a Pod security policy specified by `pod_security_policy_name`. This behaviour can also be disabled. We suggest to install a default PSP which does not allow Pods without a Security Context or using inapproriate permissions.
 
 ### Usage
 

psp.tf

@@ -0,0 +1,36 @@
+resource "kubernetes_role" "use_psp" {
+  count = var.enable_pod_security_policy ? 1 : 0
+
+  metadata {
+    name      = "psp-${var.pod_security_policy_name}"
+    namespace = kubernetes_namespace.namespace.metadata.0.name
+  }
+
+  rule {
+    api_groups     = ["policy"]
+    verbs          = ["use"]
+    resources      = ["podsecuritypolicies"]
+    resource_names = [var.pod_security_policy_name]
+  }
+}
+
+resource "kubernetes_role_binding" "psp_binding" {
+  count = var.enable_pod_security_policy ? 1 : 0
+
+  metadata {
+    name      = "psp-${var.pod_security_policy_name}"
+    namespace = kubernetes_namespace.namespace.metadata.0.name
+  }
+
+  role_ref {
+    name      = join("", kubernetes_role.use_psp.*.metadata.0.name)
+    api_group = "rbac.authorization.k8s.io"
+    kind      = "Role"
+  }
+
+  subject {
+    kind      = "Group"
+    name      = "system:authenticated"
+    namespace = kubernetes_namespace.namespace.metadata.0.name
+  }
+}

terraform.tfvars.example

@@ -13,4 +13,4 @@ image_pull_secrets = {
   docker config file
 }
 EOF
-}
+}

variables.tf

@@ -42,12 +42,6 @@ variable "image_pull_secrets" {
   description = "Pull secrets to provide to the service account to fetch docker images"
 }
 
-variable "enabled_rbac_binding" {
-  type        = bool
-  default     = true
-  description = "Deploys additional RBAC role binding to a service account named like the namespace (+-apps)"
-}
-
 variable "max_pv_claims" {
   type        = number
   default     = 30
@@ -107,6 +101,18 @@ variable "service_accounts" {
   description = "Creates additional service accounts with a dedicated RBAC role"
 }
 
+variable "enable_pod_security_policy" {
+  type        = bool
+  default     = true
+  description = "Deploys a Pod Security Policy which does not allow root or host access"
+}
+
+variable "pod_security_policy_name" {
+  type        = string
+  default     = "default"
+  description = "Allows all authenticated users/service accounts in the current namespace to use the specified security policy"
+}
+
 variable "enable_network_policies" {
   type        = bool
   default     = true