Merge remote-tracking branch 'origin/marcin/prod-3721-implement-node-bluegreen-for-mgmt-clusters' into marcin/prod-3721-implement-node-bluegreen-for-mgmt-clusters

Author: maciaszczykm

terraform/clouds/gcp/gke.tf

@@ -1,8 +1,34 @@
+locals {
+  node_pool_add = {
+    (local.active_node_group) = {
+      cluster_version = var.kubernetes_version,
+    },
+    (local.drain_node_group) = {
+      cluster_version = var.next_kubernetes_version,
+    }
+  }
+
+  full_node_pools = {
+    for k, v in var.node_pools : k => merge(v, try(lookup(local.node_pool_add, k), {}))
+    if k != local.drain_node_group || local.upgrading == true
+  }
+
+  node_pool_taints_add = {
+    (local.active_node_group) = local.upgrading ?
+      [{ key = "platform.plural.sh/pending", value = "upgrade", effect = "NO_SCHEDULE" }] : [],
+  }
+
+  full_node_pools_taints = {
+    for k, v in var.node_pools_taints : k => concat(v, try(lookup(local.node_pool_taints_add, k), []))
+    if k != local.drain_node_group || local.upgrading == true
+  }
+}
+
 module "gke" {
   source  = "terraform-google-modules/kubernetes-engine/google"
   version = "~> 33.0"
 
-  kubernetes_version     = var.kubernetes_version
+  kubernetes_version = var.next_kubernetes_version
   project_id             = var.project_id
   name                   = var.cluster_name
   regional               = true
@@ -14,8 +40,8 @@ module "gke" {
   ip_range_services      = var.ip_range_services_name
   create_service_account = true
   deletion_protection    = var.deletion_protection
-  node_pools             = var.node_pools
-  node_pools_taints      = var.node_pools_taints
+  node_pools         = [for k, v in local.full_node_pools : merge(v, { name = k })]
+  node_pools_taints  = local.full_node_pools_taints
   node_pools_labels      = var.node_pools_labels
   node_pools_tags        = var.node_pools_tags
 
@@ -27,6 +53,5 @@ module "gke" {
     google_project_service.iam,
     google_project_service.storage,
     google_project_service.dns,
-    # local.db_created,
   ]
 }

terraform/clouds/gcp/locals.tf

@@ -4,4 +4,10 @@ locals {
   db_url = format("postgresql://console:%s@%s:5432/console", random_password.password.result, try(module.pg[0].private_ip_address, ""))
   network_name = format("%s-%s", var.cluster_name, var.network)
   subnetwork_name = format("%s-%s", var.cluster_name, var.subnetwork)
+
+  upgrading         = var.kubernetes_version != var.next_kubernetes_version
+  split_vsn         = [for i in split(".", var.kubernetes_version) : tonumber(i)]
+  vsn_even          = ((tonumber(local.split_vsn[0]) * 100 + tonumber(local.split_vsn[1])) % 2) == 0
+  active_node_group = local.vsn_even ? "blue" : "green"
+  drain_node_group  = local.vsn_even ? "green" : "blue"
 }

terraform/clouds/gcp/variables.tf

@@ -18,24 +18,48 @@ variable "kubernetes_version" {
   default = "1.32"
 }
 
+variable "next_kubernetes_version" {
+  type    = string
+  default = "1.32"
+}
+
 variable "node_pools" {
   type = list(any)
-  default = [{ name = "default-node-pool", machine_type = "n2-standard-2" }]
+  default = [
+    {
+      name               = "green",
+      machine_type       = "n2-standard-2"
+      min_count          = 0
+      initial_node_count = 3
+      max_count = 10
+      # Must be set to false to allow for blue-green deployments
+      auto_upgrade       = false
+    },
+    {
+      name               = "blue"
+      machine_type       = "n2-standard-2"
+      min_count          = 0
+      initial_node_count = 3
+      max_count = 10
+      # Must be set to false to allow for blue-green deployments
+      auto_upgrade       = false
+    }
+  ]
 }
 
 variable "node_pools_taints" {
   type = map(list(object({ key = string, value = string, effect = string })))
-  default = { "all" : [], "default-node-pool" : [] }
+  default = { "all" : [], "green" : [], "blue" : [] }
 }
 
 variable "node_pools_labels" {
   type = map(map(string))
-  default = { "all" : {}, "default-node-pool" : {} }
+  default = { "all" : {}, "green" : {}, "blue" : {} }
 }
 
 variable "node_pools_tags" {
   type = map(list(string))
-  default = { "all" : [], "default-node-pool" : [] }
+  default = { "all" : [], "green" : [], "blue" : [] }
 }
 
 variable "project_id" {