Add support for internal service account to GKE nodepool module (#156)

* add support for internal service account to GKE nodepool module, fixes #62 * update shared vpc example to use internally managed service account * update shared vpc example to use internally managed service account * update hub and spoke peering example to use renamed gke nodepool variables
2020-11-07 10:48:12 +01:00
parent c31764fa7e
commit b3ae7c9454
13 changed files with 284 additions and 82 deletions
--- a/modules/gke-nodepool/README.md
+++ b/modules/gke-nodepool/README.md
@@ -4,6 +4,10 @@ This module allows simplified creation and management of individual GKE nodepool

 ## Example usage

+### Module defaults
+
+If no specific node configuration is set via variables, the module uses the provider's defaults only setting OAuth scopes to a minimal working set (devstorage read-only, logging and monitoring write) and the node machine type to `n1-standard-1`. The service account set by the provider in this case is the GCE default service account.
+
 ```hcl
 module "cluster-1-nodepool-1" {
  source                      = "../modules/gke-nodepool"
@@ -14,6 +18,21 @@ module "cluster-1-nodepool-1" {
 }
 ```

+### Internally managed service account
+
+To have the module auto-create a service account for the nodes, set the `node_service_account_create` variable to `true`. When a service account is created by the module, OAuth scopes are set to `cloud-platform` by default. The service account resource and email (in both plain and IAM formats) are then available in outputs to assign IAM roles from your own code.
+
+```hcl
+module "cluster-1-nodepool-1" {
+  source                      = "../modules/gke-nodepool"
+  project_id                  = "myproject"
+  cluster_name                = "cluster-1"
+  location                    = "europe-west1-b"
+  name                        = "nodepool-1"
+  node_service_account_create = true
+}
+```
+
 <!-- BEGIN TFDOC -->
 ## Variables

@@ -28,23 +47,24 @@ module "cluster-1-nodepool-1" {
 | *management_config* | Optional node management configuration. | <code title="object&#40;&#123;&#10;auto_repair  &#61; bool&#10;auto_upgrade &#61; bool&#10;&#125;&#41;">object({...})</code> |  | <code title="">null</code> |
 | *max_pods_per_node* | Maximum number of pods per node. | <code title="">number</code> |  | <code title="">null</code> |
 | *name* | Optional nodepool name. | <code title="">string</code> |  | <code title="">null</code> |
-| *node_config_disk_size* | Node disk size, defaults to 100GB. | <code title="">number</code> |  | <code title="">100</code> |
-| *node_config_disk_type* | Node disk type, defaults to pd-standard. | <code title="">string</code> |  | <code title="">pd-standard</code> |
-| *node_config_guest_accelerator* | Map of type and count of attached accelerator cards. | <code title="map&#40;number&#41;">map(number)</code> |  | <code title="">{}</code> |
-| *node_config_image_type* | Nodes image type. | <code title="">string</code> |  | <code title="">null</code> |
-| *node_config_labels* | Kubernetes labels attached to nodes. | <code title="map&#40;string&#41;">map(string)</code> |  | <code title="">{}</code> |
-| *node_config_local_ssd_count* | Number of local SSDs attached to nodes. | <code title="">number</code> |  | <code title="">0</code> |
-| *node_config_machine_type* | Nodes machine type. | <code title="">string</code> |  | <code title="">n1-standard-1</code> |
-| *node_config_metadata* | Metadata key/value pairs assigned to nodes. Set disable-legacy-endpoints to true when using this variable. | <code title="map&#40;string&#41;">map(string)</code> |  | <code title="">null</code> |
-| *node_config_min_cpu_platform* | Minimum CPU platform for nodes. | <code title="">string</code> |  | <code title="">null</code> |
-| *node_config_oauth_scopes* | Set of Google API scopes for the nodes service account. Include logging-write, monitoring, and storage-ro when using this variable. | <code title="list&#40;string&#41;">list(string)</code> |  | <code title="">["logging-write", "monitoring", "monitoring-write", "storage-ro"]</code> |
-| *node_config_preemptible* | Use preemptible VMs for nodes. | <code title="">bool</code> |  | <code title="">null</code> |
-| *node_config_sandbox_config* | GKE Sandbox configuration. Needs image_type set to COS_CONTAINERD and node_version set to 1.12.7-gke.17 when using this variable. | <code title="">string</code> |  | <code title="">null</code> |
-| *node_config_service_account* | Service account used for nodes. | <code title="">string</code> |  | <code title="">null</code> |
-| *node_config_shielded_instance_config* | Shielded instance options. | <code title="object&#40;&#123;&#10;enable_secure_boot          &#61; bool&#10;enable_integrity_monitoring &#61; bool&#10;&#125;&#41;">object({...})</code> |  | <code title="">null</code> |
-| *node_config_tags* | Network tags applied to nodes. | <code title="list&#40;string&#41;">list(string)</code> |  | <code title="">null</code> |
 | *node_count* | Number of nodes per instance group, can be updated after creation. Ignored when autoscaling is set. | <code title="">number</code> |  | <code title="">null</code> |
+| *node_disk_size* | Node disk size, defaults to 100GB. | <code title="">number</code> |  | <code title="">100</code> |
+| *node_disk_type* | Node disk type, defaults to pd-standard. | <code title="">string</code> |  | <code title="">pd-standard</code> |
+| *node_guest_accelerator* | Map of type and count of attached accelerator cards. | <code title="map&#40;number&#41;">map(number)</code> |  | <code title="">{}</code> |
+| *node_image_type* | Nodes image type. | <code title="">string</code> |  | <code title="">null</code> |
+| *node_labels* | Kubernetes labels attached to nodes. | <code title="map&#40;string&#41;">map(string)</code> |  | <code title="">{}</code> |
+| *node_local_ssd_count* | Number of local SSDs attached to nodes. | <code title="">number</code> |  | <code title="">0</code> |
 | *node_locations* | Optional list of zones in which nodes should be located. Uses cluster locations if unset. | <code title="list&#40;string&#41;">list(string)</code> |  | <code title="">null</code> |
+| *node_machine_type* | Nodes machine type. | <code title="">string</code> |  | <code title="">n1-standard-1</code> |
+| *node_metadata* | Metadata key/value pairs assigned to nodes. Set disable-legacy-endpoints to true when using this variable. | <code title="map&#40;string&#41;">map(string)</code> |  | <code title="">null</code> |
+| *node_min_cpu_platform* | Minimum CPU platform for nodes. | <code title="">string</code> |  | <code title="">null</code> |
+| *node_preemptible* | Use preemptible VMs for nodes. | <code title="">bool</code> |  | <code title="">null</code> |
+| *node_sandbox_config* | GKE Sandbox configuration. Needs image_type set to COS_CONTAINERD and node_version set to 1.12.7-gke.17 when using this variable. | <code title="">string</code> |  | <code title="">null</code> |
+| *node_service_account* | Service account email. Unused if service account is auto-created. | <code title="">string</code> |  | <code title="">null</code> |
+| *node_service_account_create* | Auto-create service account. | <code title="">bool</code> |  | <code title="">false</code> |
+| *node_service_account_scopes* | Scopes applied to service account. Default to: 'cloud-platform' when creating a service account; 'devstorage.read_only', 'logging.write', 'monitoring.write' otherwise. | <code title="list&#40;string&#41;">list(string)</code> |  | <code title="">[]</code> |
+| *node_shielded_instance_config* | Shielded instance options. | <code title="object&#40;&#123;&#10;enable_secure_boot          &#61; bool&#10;enable_integrity_monitoring &#61; bool&#10;&#125;&#41;">object({...})</code> |  | <code title="">null</code> |
+| *node_tags* | Network tags applied to nodes. | <code title="list&#40;string&#41;">list(string)</code> |  | <code title="">null</code> |
 | *upgrade_config* | Optional node upgrade configuration. | <code title="object&#40;&#123;&#10;max_surge       &#61; number&#10;max_unavailable &#61; number&#10;&#125;&#41;">object({...})</code> |  | <code title="">null</code> |
 | *workload_metadata_config* | Metadata configuration to expose to workloads on the node pool. | <code title="">string</code> |  | <code title="">GKE_METADATA_SERVER</code> |

@@ -53,4 +73,7 @@ module "cluster-1-nodepool-1" {
 | name | description | sensitive |
 |---|---|:---:|
 | name | Nodepool name. |  |
+| service_account | Service account resource. |  |
+| service_account_email | Service account email. |  |
+| service_account_iam_email | Service account email. |  |
 <!-- END TFDOC -->
--- a/modules/gke-nodepool/main.tf
+++ b/modules/gke-nodepool/main.tf
@@ -14,6 +14,38 @@
 * limitations under the License.
 */

+locals {
+  service_account_email = (
+    var.node_service_account_create
+    ? (
+      length(google_service_account.service_account) > 0
+      ? google_service_account.service_account[0].email
+      : null
+    )
+    : var.node_service_account
+  )
+  service_account_scopes = (
+    length(var.node_service_account_scopes) > 0
+    ? var.node_service_account_scopes
+    : (
+      var.node_service_account_create
+      ? ["https://www.googleapis.com/auth/cloud-platform"]
+      : [
+        "https://www.googleapis.com/auth/devstorage.read_only",
+        "https://www.googleapis.com/auth/logging.write",
+        "https://www.googleapis.com/auth/monitoring.write"
+      ]
+    )
+  )
+}
+
+resource "google_service_account" "service_account" {
+  count        = var.node_service_account_create ? 1 : 0
+  project      = var.project_id
+  account_id   = "tf-gke-${var.cluster_name}-${var.name}"
+  display_name = "Terraform GKE ${var.cluster_name} ${var.name}."
+}
+
 resource "google_container_node_pool" "nodepool" {
  provider = google-beta

@@ -29,21 +61,21 @@ resource "google_container_node_pool" "nodepool" {
  version            = var.gke_version

  node_config {
-    disk_size_gb     = var.node_config_disk_size
-    disk_type        = var.node_config_disk_type
-    image_type       = var.node_config_image_type
-    labels           = var.node_config_labels
-    local_ssd_count  = var.node_config_local_ssd_count
-    machine_type     = var.node_config_machine_type
-    metadata         = var.node_config_metadata
-    min_cpu_platform = var.node_config_min_cpu_platform
-    oauth_scopes     = var.node_config_oauth_scopes
-    preemptible      = var.node_config_preemptible
-    service_account  = var.node_config_service_account
-    tags             = var.node_config_tags
+    disk_size_gb     = var.node_disk_size
+    disk_type        = var.node_disk_type
+    image_type       = var.node_image_type
+    labels           = var.node_labels
+    local_ssd_count  = var.node_local_ssd_count
+    machine_type     = var.node_machine_type
+    metadata         = var.node_metadata
+    min_cpu_platform = var.node_min_cpu_platform
+    oauth_scopes     = local.service_account_scopes
+    preemptible      = var.node_preemptible
+    service_account  = local.service_account_email
+    tags             = var.node_tags

    dynamic guest_accelerator {
-      for_each = var.node_config_guest_accelerator
+      for_each = var.node_guest_accelerator
      iterator = config
      content {
        type  = config.key
@@ -53,8 +85,8 @@ resource "google_container_node_pool" "nodepool" {

    dynamic sandbox_config {
      for_each = (
-        var.node_config_sandbox_config != null
-        ? [var.node_config_sandbox_config]
+        var.node_sandbox_config != null
+        ? [var.node_sandbox_config]
        : []
      )
      iterator = config
@@ -65,8 +97,8 @@ resource "google_container_node_pool" "nodepool" {

    dynamic shielded_instance_config {
      for_each = (
-        var.node_config_shielded_instance_config != null
-        ? [var.node_config_shielded_instance_config]
+        var.node_shielded_instance_config != null
+        ? [var.node_shielded_instance_config]
        : []
      )
      iterator = config
--- a/modules/gke-nodepool/outputs.tf
+++ b/modules/gke-nodepool/outputs.tf
@@ -18,3 +18,25 @@ output "name" {
  description = "Nodepool name."
  value       = google_container_node_pool.nodepool.name
 }
+
+output "service_account" {
+  description = "Service account resource."
+  value = (
+    var.node_service_account_create
+    ? google_service_account.service_account[0]
+    : null
+  )
+}
+
+output "service_account_email" {
+  description = "Service account email."
+  value       = local.service_account_email
+}
+
+output "service_account_iam_email" {
+  description = "Service account email."
+  value = join("", [
+    "serviceAccount:",
+    local.service_account_email == null ? "" : local.service_account_email
+  ])
+}
--- a/modules/gke-nodepool/variables.tf
+++ b/modules/gke-nodepool/variables.tf
@@ -66,85 +66,93 @@ variable "name" {
  default     = null
 }

-variable "node_config_disk_size" {
+variable "node_disk_size" {
  description = "Node disk size, defaults to 100GB."
  type        = number
  default     = 100
 }

-variable "node_config_disk_type" {
+variable "node_disk_type" {
  description = "Node disk type, defaults to pd-standard."
  type        = string
  default     = "pd-standard"
 }

-variable "node_config_guest_accelerator" {
+variable "node_guest_accelerator" {
  description = "Map of type and count of attached accelerator cards."
  type        = map(number)
  default     = {}
 }

-variable "node_config_image_type" {
+variable "node_image_type" {
  description = "Nodes image type."
  type        = string
  default     = null
 }

-variable "node_config_labels" {
+variable "node_labels" {
  description = "Kubernetes labels attached to nodes."
  type        = map(string)
  default     = {}
 }

-variable "node_config_local_ssd_count" {
+variable "node_local_ssd_count" {
  description = "Number of local SSDs attached to nodes."
  type        = number
  default     = 0
 }

-variable "node_config_machine_type" {
+variable "node_machine_type" {
  description = "Nodes machine type."
  type        = string
  default     = "n1-standard-1"
 }

-variable "node_config_metadata" {
+variable "node_metadata" {
  description = "Metadata key/value pairs assigned to nodes. Set disable-legacy-endpoints to true when using this variable."
  type        = map(string)
  default     = null
 }

-variable "node_config_min_cpu_platform" {
+variable "node_min_cpu_platform" {
  description = "Minimum CPU platform for nodes."
  type        = string
  default     = null
 }

-variable "node_config_oauth_scopes" {
-  description = "Set of Google API scopes for the nodes service account. Include logging-write, monitoring, and storage-ro when using this variable."
-  type        = list(string)
-  default     = ["logging-write", "monitoring", "monitoring-write", "storage-ro"]
-}
-
-variable "node_config_preemptible" {
+variable "node_preemptible" {
  description = "Use preemptible VMs for nodes."
  type        = bool
  default     = null
 }

-variable "node_config_sandbox_config" {
+variable "node_sandbox_config" {
  description = "GKE Sandbox configuration. Needs image_type set to COS_CONTAINERD and node_version set to 1.12.7-gke.17 when using this variable."
  type        = string
  default     = null
 }

-variable "node_config_service_account" {
-  description = "Service account used for nodes."
+variable "node_service_account" {
+  description = "Service account email. Unused if service account is auto-created."
  type        = string
  default     = null
 }

-variable "node_config_shielded_instance_config" {
+variable "node_service_account_create" {
+  description = "Auto-create service account."
+  type        = bool
+  default     = false
+}
+
+# scopes and scope aliases list
+# https://cloud.google.com/sdk/gcloud/reference/compute/instances/create#--scopes
+variable "node_service_account_scopes" {
+  description = "Scopes applied to service account. Default to: 'cloud-platform' when creating a service account; 'devstorage.read_only', 'logging.write', 'monitoring.write' otherwise."
+  type        = list(string)
+  default     = []
+}
+
+variable "node_shielded_instance_config" {
  description = "Shielded instance options."
  type = object({
    enable_secure_boot          = bool
@@ -153,13 +161,13 @@ variable "node_config_shielded_instance_config" {
  default = null
 }

-variable "node_config_tags" {
+variable "node_tags" {
  description = "Network tags applied to nodes."
  type        = list(string)
  default     = null
 }

-# variable "node_config_taint" {
+# variable "node_taint" {
 #   description = "Kubernetes taints applied to nodes."
 #   type        = string
 #   default     = null