Add possibility for volume to be created out of terraform

Author: mboisson

aws/infrastructure.tf

@@ -164,7 +164,9 @@ resource "aws_instance" "instances" {
 }
 
 resource "aws_ebs_volume" "volumes" {
-  for_each          = module.design.volumes
+  for_each = {
+    for x, values in module.design.volumes : x => values if lookup(values, "managed", true)
+  }
   availability_zone = local.availability_zone
   size              = each.value.size
   type              = lookup(each.value, "type", null)
@@ -175,17 +177,32 @@ resource "aws_ebs_volume" "volumes" {
   }
 }
 
+data "aws_ebs_volume" "existing_volumes" {
+  for_each = {
+    for x, values in module.design.volumes : x => values if !lookup(values, "managed", true)
+  }
+
+  filter {
+    name   = "tag:Name"
+    values = ["${var.cluster_name}-${each.key}"]
+  }
+}
+
 locals {
   device_names = [
     "/dev/sdf", "/dev/sdg", "/dev/sdh", "/dev/sdi", "/dev/sdj",
     "/dev/sdk", "/dev/sdl", "/dev/sdm", "/dev/sdn", "/dev/sdp"
   ]
+  volume_ids = {
+    for key, values in module.design.volumes :
+    key => lookup(values, "managed", true) ? aws_ebs_volume.volumes[key].id : data.aws_ebs_volume.existing_volumes[key].id
+  }
 }
 
 resource "aws_volume_attachment" "attachments" {
   for_each     = module.design.volumes
   device_name  = local.device_names[index(module.design.volume_per_instance[each.value.instance], replace(each.key, "${each.value.instance}-", ""))]
-  volume_id    = aws_ebs_volume.volumes[each.key].id
+  volume_id    = local.volume_ids[each.key]
   instance_id  = aws_instance.instances[each.value.instance].id
   skip_destroy = true
 }
@@ -207,7 +224,7 @@ locals {
         pv_key => {
           for name, specs in pv_values :
           name => merge(
-            { glob = "/dev/disk/by-id/*${replace(aws_ebs_volume.volumes["${x}-${pv_key}-${name}"].id, "-", "")}" },
+            { glob = "/dev/disk/by-id/*${replace(local.volume_ids["${x}-${pv_key}-${name}"], "-", "")}" },
             specs,
           )
         } if contains(values.tags, pv_key)

azure/infrastructure.tf

@@ -127,7 +127,9 @@ resource "azurerm_linux_virtual_machine" "instances" {
 }
 
 resource "azurerm_managed_disk" "volumes" {
-  for_each             = module.design.volumes
+  for_each             = {
+    for x, values in module.design.volumes : x => values if lookup(values, "managed", true)
+  }
   name                 = format("%s-%s", var.cluster_name, each.key)
   location             = var.location
   resource_group_name  = local.resource_group_name
@@ -136,9 +138,24 @@ resource "azurerm_managed_disk" "volumes" {
   disk_size_gb         = each.value.size
 }
 
+data "azurerm_managed_disk" "existing_volumes" {
+  for_each             = {
+    for x, values in module.design.volumes : x => values if ! lookup(values, "managed", true)
+  }
+  name                 = format("%s-%s", var.cluster_name, each.key)
+  resource_group_name  = local.resource_group_name
+}
+
+locals {
+  volume_ids = {
+    for key, values in module.design.volumes:
+    key => lookup(values, "managed", true) ? azurerm_managed_disk.volumes[key].id: data.azurerm_managed_disk.existing_volumes[key].id
+  }
+}
+
 resource "azurerm_virtual_machine_data_disk_attachment" "attachments" {
   for_each           = module.design.volumes
-  managed_disk_id    = azurerm_managed_disk.volumes[each.key].id
+  managed_disk_id    = local.volume_ids[each.key]
   virtual_machine_id = azurerm_linux_virtual_machine.instances[each.value.instance].id
   lun                = index(module.design.volume_per_instance[each.value.instance], replace(each.key, "${each.value.instance}-", ""))
   caching            = "ReadWrite"

gcp/infrastructure.tf

@@ -134,17 +134,37 @@ resource "google_compute_instance" "instances" {
 }
 
 resource "google_compute_disk" "volumes" {
-  for_each = module.design.volumes
+  for_each = {
+    for x, values in module.design.volumes : x => values if lookup(values, "managed", true)
+  }
   name     = "${var.cluster_name}-${each.key}"
   type     = lookup(each.value, "type", "pd-standard")
   zone     = local.zone
   size     = each.value.size
 }
 
+data "google_compute_disk" "existing_volumes" {
+  for_each = {
+    for x, values in module.design.volumes : x => values if ! lookup(values, "managed", true)
+  }
+  name     = "${var.cluster_name}-${each.key}"
+}
+
+locals{
+  volume_self_links = {
+    for key, values in module.design.volumes:
+    key => lookup(values, "managed", true) ? google_compute_disk.volumes[key].self_link : data.google_compute_disk.existing_volumes[key].self_link
+  }
+  volume_device_names = {
+    for key, values in module.design.volumes:
+    key => lookup(values, "managed", true) ? google_compute_disk.volumes[key].name : data.google_compute_disk.existing_volumes[key].name
+  }
+}
+
 resource "google_compute_attached_disk" "attachments" {
   for_each    = module.design.volumes
-  disk        = google_compute_disk.volumes[each.key].self_link
-  device_name = google_compute_disk.volumes[each.key].name
+  disk        = local.volume_self_links[each.key]
+  device_name = local.volume_device_names[each.key]
   mode        = "READ_WRITE"
   instance    = google_compute_instance.instances[each.value.instance].self_link
 }

openstack/infrastructure.tf

@@ -97,7 +97,9 @@ resource "openstack_compute_instance_v2" "instances" {
 }
 
 resource "openstack_blockstorage_volume_v3" "volumes" {
-  for_each             = module.design.volumes
+  for_each = {
+    for x, values in module.design.volumes : x => values if lookup(values, "managed", true)
+  }
   name                 = "${var.cluster_name}-${each.key}"
   description          = "${var.cluster_name} ${each.key}"
   size                 = each.value.size
@@ -106,10 +108,24 @@ resource "openstack_blockstorage_volume_v3" "volumes" {
   enable_online_resize = lookup(each.value, "enable_resize", false)
 }
 
+data "openstack_blockstorage_volume_v3" "existing_volumes" {
+  for_each = {
+    for x, values in module.design.volumes : x => values if !lookup(values, "managed", true)
+  }
+  name = "${var.cluster_name}-${each.key}"
+}
+
+locals {
+  volume_ids = {
+    for key, values in module.design.volumes :
+    key => lookup(values, "managed", true) ? openstack_blockstorage_volume_v3.volumes[key].id : data.openstack_blockstorage_volume_v3.existing_volumes[key].id
+  }
+}
+
 resource "openstack_compute_volume_attach_v2" "attachments" {
   for_each    = module.design.volumes
   instance_id = openstack_compute_instance_v2.instances[each.value.instance].id
-  volume_id   = openstack_blockstorage_volume_v3.volumes[each.key].id
+  volume_id   = local.volume_ids[each.key]
 }
 
 locals {
@@ -132,7 +148,7 @@ locals {
         pv_key => {
           for name, specs in pv_values :
           name => merge(
-            { glob = "/dev/disk/by-id/*${substr(openstack_blockstorage_volume_v3.volumes["${x}-${pv_key}-${name}"].id, 0, 20)}" },
+            { glob = "/dev/disk/by-id/*${substr(local.volume_ids["${x}-${pv_key}-${name}"], 0, 20)}" },
             specs,
           )
         } if contains(values.tags, pv_key)