terraform-provider: implement constellation_cluster resource (#2691)

* terraform: move module to legacy-directory

* constellation-lib: refactor service account marshalling

* terraform-provider: normalize Azure image URIs

* constellation-lib: refactor Kubeconfig endpoint rewriting

* terraform-provider: add conversion functions for AWS and GCP

* terraform-provider: implement `constellation_cluster` resource

* terraform-provider: refactor conversion

* terraform-provider: implement image and k8s upgrades

* terraform-provider: fix linter checks

* terraform-provider: refactor to bundle init & upgrade method

* constellation-lib: rewrite Kubeconfig endpoint in init

* terraform-provider: bind logger and dialer constructors to struct

* terraform-provider: move applier to function pointer

* terraform-provider: gcp conversion fixes

Signed-off-by: Moritz Sanft <58110325+msanft@users.noreply.github.com>

* terraform-provider: fix Azure UAMI input

* terraform-provider: rename Kubeconfig variable

* terraform-provider: tidy

* terraform-provider: regenerate docs

* constellation-lib: provide Kubeconfig in testing initserver

---------

Signed-off-by: Moritz Sanft <58110325+msanft@users.noreply.github.com>

terraform/legacy-module/constellation-cluster/variables.tf

@@ -0,0 +1,133 @@
+variable "constellation_version" {
+  type        = string
+  description = "Constellation CLI version to use."
+  default     = "@@CONSTELLATION_VERSION@@"
+}
+
+variable "image" {
+  type        = string
+  description = "The node image reference or semantic release version."
+}
+
+variable "csp" {
+  type        = string
+  description = "The cloud service provider to use."
+  validation {
+    condition     = var.csp == "aws" || var.csp == "gcp" || var.csp == "azure"
+    error_message = "The cloud service provider to use."
+  }
+}
+
+variable "node_groups" {
+  type = map(object({
+    role          = string
+    initial_count = optional(number)
+    instance_type = string
+    disk_size     = number
+    disk_type     = string
+    zone          = optional(string, "")       # For AWS, GCP
+    zones         = optional(list(string), []) # For Azure
+  }))
+  description = "A map of node group names to node group configurations."
+  validation {
+    condition     = can([for group in var.node_groups : group.role == "control-plane" || group.role == "worker"])
+    error_message = "The role has to be 'control-plane' or 'worker'."
+  }
+}
+
+variable "name" {
+  type        = string
+  description = "Name used in the cluster's named resources / cluster name."
+}
+
+variable "uid" {
+  type        = string
+  description = "The UID of the Constellation."
+}
+
+variable "clusterEndpoint" {
+  type        = string
+  description = "Endpoint of the cluster."
+}
+
+variable "inClusterEndpoint" {
+  type        = string
+  description = "The endpoint the cluster uses to reach itself. This might differ from the ClusterEndpoint in case e.g. an internal load balancer is used."
+}
+
+variable "initSecretHash" {
+  type        = string
+  description = "Init secret hash."
+}
+
+variable "ipCidrNode" {
+  type        = string
+  description = "Node IP CIDR."
+}
+
+variable "serviceCidr" {
+  type        = string
+  default     = ""
+  description = "Kubernetes service CIDR. This is only used during first initialization of Constellation."
+}
+
+variable "apiServerCertSANs" {
+  type        = list(string)
+  description = "List of additional SANs (Subject Alternative Names) for the Kubernetes API server certificate."
+}
+
+variable "aws_config" {
+  type = object({
+    region                             = string
+    zone                               = string
+    iam_instance_profile_worker_nodes  = string
+    iam_instance_profile_control_plane = string
+  })
+  description = "The cluster config for AWS."
+  default     = null
+}
+
+variable "azure_config" {
+  type = object({
+    subscription             = string
+    tenant                   = string
+    location                 = string
+    resourceGroup            = string
+    userAssignedIdentity     = string
+    deployCSIDriver          = bool
+    secureBoot               = bool
+    maaURL                   = string
+    networkSecurityGroupName = string
+    loadBalancerName         = string
+  })
+  description = "The cluster config for Azure."
+  default     = null
+}
+
+variable "gcp_config" {
+  type = object({
+    region            = string
+    zone              = string
+    project           = string
+    ipCidrPod         = string
+    serviceAccountKey = string
+  })
+  description = "The cluster config for GCP."
+  default     = null
+}
+
+variable "kubernetes_version" {
+  type        = string
+  description = "Kubernetes version."
+}
+
+variable "microservice_version" {
+  type        = string
+  description = "Microservice version."
+}
+
+variable "debug" {
+  type        = bool
+  default     = false
+  description = "DON'T USE IN PRODUCTION: Enable debug mode and allow the use of debug images."
+}