diff --git a/juju/home-maas/00-variables.tf b/juju/home-maas/00-variables.tf
index 455903a..4685ba4 100644
--- a/juju/home-maas/00-variables.tf
+++ b/juju/home-maas/00-variables.tf
@@ -11,16 +11,26 @@ variable "num_units" {
 
 variable "controller_ids" {
   type    = list(string)
-  default = ["100", "101", "102", 
+  default = ["100", "101", "102",
              "103", "104", "105"]
 }
 
+variable "controller_ids_high" {
+  type    = list(string)
+  default = ["103", "104", "105"]
+}
+
 variable "compute_ids" {
   type    = list(string)
-  default = ["1000", "1001", "1002", "1003", 
+  default = ["1000", "1001", "1002", "1003",
              "1004", "1005", "1006", "1007"]
 }
 
+variable "sdn_ids" {
+  type    = list(string)
+  default = ["400", "401", "402"]
+}
+
 variable "apt_mirror" {
     type = string
     default = "192.168.1.12"
@@ -69,17 +79,17 @@ variable mysql-router-channel {
     default = "8.0/stable"
 }
 
-variable "hacluster-channel" {
+variable hacluster-channel {
     type = string
     default = "2.0.3/stable"
 }
 
-variable "rabbitmq-server-channel" {
+variable rabbitmq-server-channel {
     type = string
     default = "3.8/stable"
 }
 
-variable "ceph-channel" {
+variable ceph-channel {
     type = string
     default = "octopus/stable"
 }
diff --git a/juju/home-maas/04-keystone.tf b/juju/home-maas/04-keystone.tf
index 449586b..fb5b1e4 100644
--- a/juju/home-maas/04-keystone.tf
+++ b/juju/home-maas/04-keystone.tf
@@ -1,7 +1,7 @@
 resource "juju_machine" "keystone" {
   count       = var.num_units
   model       = var.model-name
-  placement   = join(":", ["lxd", juju_machine.all_machines[var.controller_ids[count.index+var.num_units]].machine_id])
+  placement   = join(":", ["lxd", juju_machine.all_machines[var.controller_ids_high[count.index+var.num_units]].machine_id])
   constraints = "spaces=oam"
 }
 
@@ -18,8 +18,8 @@ resource "juju_application" "keystone" {
   units = var.num_units
 
   placement = "${join(",", sort([
-    for index, _ in slice(var.controller_ids, var.num_units, length(var.controller_ids)) : 
-        juju_machine.keystone[index].machine_id
+    for res in juju_machine.keystone :
+        res.machine_id
   ]))}"
 
   endpoint_bindings = [{
diff --git a/juju/home-maas/04-mysql.tf b/juju/home-maas/04-mysql.tf
index 0b41852..277d0ff 100644
--- a/juju/home-maas/04-mysql.tf
+++ b/juju/home-maas/04-mysql.tf
@@ -19,8 +19,8 @@ resource "juju_application" "mysql-innodb-cluster" {
   units = var.num_units
 
   placement = "${join(",", sort([
-    for index, _ in slice(var.controller_ids, 0, var.num_units+1) : 
-        juju_machine.mysql[index].machine_id
+    for res in juju_machine.mysql :
+        res.machine_id
   ]))}"
 
   endpoint_bindings = [{
diff --git a/juju/home-maas/04-rmq.tf b/juju/home-maas/04-rmq.tf
index a577516..106cc27 100644
--- a/juju/home-maas/04-rmq.tf
+++ b/juju/home-maas/04-rmq.tf
@@ -18,8 +18,8 @@ resource "juju_application" "rabbitmq-server" {
   units = 3
 
   placement = "${join(",", sort([
-    for index, _ in slice(var.controller_ids, var.num_units, length(var.controller_ids)) : 
-        juju_machine.rmq[index].machine_id
+    for res in juju_machine.rmq :
+        res.machine_id
   ]))}"
 
   endpoint_bindings = [{
diff --git a/juju/home-maas/05-ceilometer.tf b/juju/home-maas/05-ceilometer.tf
index 18d0751..1897407 100644
--- a/juju/home-maas/05-ceilometer.tf
+++ b/juju/home-maas/05-ceilometer.tf
@@ -18,8 +18,8 @@ resource "juju_application" "ceilometer" {
   units = 3
 
   placement = "${join(",", sort([
-    for index, _ in slice(var.controller_ids, var.num_units, length(var.controller_ids)) : 
-        juju_machine.ceilometer[index].machine_id
+    for res in juju_machine.ceilometer :
+        res.machine_id
   ]))}"
 
   endpoint_bindings = [{
diff --git a/juju/home-maas/05-ceph.tf b/juju/home-maas/05-ceph.tf
index 3451a42..f87b058 100644
--- a/juju/home-maas/05-ceph.tf
+++ b/juju/home-maas/05-ceph.tf
@@ -5,13 +5,13 @@ resource "juju_application" "ceph-osd" {
 
   charm {
     name    = "ceph-osd"
-    channel = var.ceph-osd-channel
+    channel = var.ceph-channel
   }
 
   units = length(var.compute_ids)
 
   placement = "${join(",", sort([
-    for index, _ in var.compute_ids : 
+    for index, _ in var.compute_ids :
       juju_machine.all_machines[index].machine_id
   ]))}"
 
@@ -47,8 +47,8 @@ resource "juju_application" "ceph-mon" {
   units = var.num_units
 
   placement = "${join(",", sort([
-    for index, _ in slice(var.controller_ids, 0, var.num_units+1) : 
-        juju_machine.ceph-mon[index].machine_id
+    for res in juju_machine.ceph-mon :
+        res.machine_id
   ]))}"
 
   endpoint_bindings = [{
@@ -98,8 +98,8 @@ resource "juju_application" "ceph-radosgw" {
   units = var.num_units
 
   placement = "${join(",", sort([
-    for index, _ in slice(var.controller_ids, 0, var.num_units+1) : 
-        juju_machine.ceph-rgw[index].machine_id
+    for res in juju_machine.ceph-rgw :
+        res.machine_id
   ]))}"
 
   endpoint_bindings = [{
diff --git a/juju/home-maas/05-cinder.tf b/juju/home-maas/05-cinder.tf
index bc0fd3e..099b1c6 100644
--- a/juju/home-maas/05-cinder.tf
+++ b/juju/home-maas/05-cinder.tf
@@ -18,8 +18,8 @@ resource "juju_application" "cinder" {
   units = var.num_units
 
   placement = "${join(",", sort([
-    for index, _ in slice(var.controller_ids, 0, var.num_units+1) : 
-        juju_machine.cinder[index].machine_id
+    for res in juju_machine.cinder :
+        res.machine_id
   ]))}"
 
   endpoint_bindings = [{
diff --git a/juju/home-maas/05-glance.tf b/juju/home-maas/05-glance.tf
index 9b382ec..de7b258 100644
--- a/juju/home-maas/05-glance.tf
+++ b/juju/home-maas/05-glance.tf
@@ -18,8 +18,8 @@ resource "juju_application" "glance" {
   units = var.num_units
 
   placement = "${join(",", sort([
-    for index, _ in slice(var.controller_ids, 0, var.num_units+1) : 
-        juju_machine.glance[index].machine_id
+    for res in juju_machine.glance :
+        res.machine_id
   ]))}"
 
   endpoint_bindings = [{
diff --git a/juju/home-maas/05-gnocchi.tf b/juju/home-maas/05-gnocchi.tf
index bba71cd..c384bf3 100644
--- a/juju/home-maas/05-gnocchi.tf
+++ b/juju/home-maas/05-gnocchi.tf
@@ -1,7 +1,7 @@
 resource "juju_machine" "gnocchi" {
   count       = var.num_units
   model       = var.model-name
-  placement   = join(":", ["lxd", juju_machine.all_machines[var.controller_ids[count.index+var.num_units]].machine_id])
+  placement   = join(":", ["lxd", juju_machine.all_machines[var.controller_ids_high[count.index+var.num_units]].machine_id])
   constraints = "spaces=oam,ceph-access"
 }
 
@@ -18,8 +18,8 @@ resource "juju_application" "gnocchi" {
   units = var.num_units
 
   placement = "${join(",", sort([
-    for index, _ in slice(var.controller_ids, var.num_units, length(var.controller_ids)) : 
-        juju_machine.gnocchi[index].machine_id
+    for res in juju_machine.gnocchi :
+        res.machine_id
   ]))}"
 
   endpoint_bindings = [{
diff --git a/juju/home-maas/05-heat.tf b/juju/home-maas/05-heat.tf
index 95b7464..2cab20a 100644
--- a/juju/home-maas/05-heat.tf
+++ b/juju/home-maas/05-heat.tf
@@ -18,8 +18,8 @@ resource "juju_application" "heat" {
   units = var.num_units
 
   placement = "${join(",", sort([
-    for index, _ in slice(var.controller_ids, 0, var.num_units+1) : 
-        juju_machine.heat[index].machine_id
+    for res in juju_machine.heat :
+        res.machine_id
   ]))}"
 
   endpoint_bindings = [{
diff --git a/juju/home-maas/05-memcache.tf b/juju/home-maas/05-memcache.tf
index b6f82de..b8efaab 100644
--- a/juju/home-maas/05-memcache.tf
+++ b/juju/home-maas/05-memcache.tf
@@ -19,8 +19,8 @@ resource "juju_application" "memcached" {
   units = var.num_units
 
   placement = "${join(",", sort([
-    for index, _ in slice(var.controller_ids, 0, var.num_units+1) : 
-        juju_machine.memcached[index].machine_id
+    for res in juju_machine.memcache :
+        res.machine_id
   ]))}"
 
 
diff --git a/juju/home-maas/05-nova.tf b/juju/home-maas/05-nova.tf
index 0e99924..652e0e5 100644
--- a/juju/home-maas/05-nova.tf
+++ b/juju/home-maas/05-nova.tf
@@ -1,7 +1,7 @@
 resource "juju_machine" "ncc" {
   count       = var.num_units
   model       = var.model-name
-  placement   = join(":", ["lxd", juju_machine.all_machines[var.controller_ids[count.index+var.num_units]].machine_id])
+  placement   = join(":", ["lxd", juju_machine.all_machines[var.controller_ids_high[count.index+var.num_units]].machine_id])
   constraints = "spaces=oam"
 }
 
@@ -18,8 +18,8 @@ resource "juju_application" "nova-cloud-controller" {
   units = var.num_units
 
   placement = "${join(",", sort([
-    for index, _ in slice(var.controller_ids, var.num_units, length(var.controller_ids)) : 
-        juju_machine.ncc[index].machine_id
+    for res in juju_machine.ncc :
+        res.machine_id
   ]))}"
 
   endpoint_bindings = [{
diff --git a/juju/home-maas/05-placement.tf b/juju/home-maas/05-placement.tf
index d15278c..b233dc1 100644
--- a/juju/home-maas/05-placement.tf
+++ b/juju/home-maas/05-placement.tf
@@ -1,7 +1,7 @@
 resource "juju_machine" "placement" {
   count       = var.num_units
   model       = var.model-name
-  placement   = join(":", ["lxd", juju_machine.all_machines[var.controller_ids[count.index+var.num_units]].machine_id])
+  placement   = join(":", ["lxd", juju_machine.all_machines[var.controller_ids_high[count.index+var.num_units]].machine_id])
   constraints = "spaces=oam"
 }
 
@@ -18,8 +18,8 @@ resource "juju_application" "placement" {
   units = var.num_units
 
   placement = "${join(",", sort([
-    for index, _ in slice(var.controller_ids, var.num_units, length(var.controller_ids)) : 
-        juju_machine.placement[index].machine_id
+    for res in juju_machine.placement :
+        res.machine_id
   ]))}"
 
   endpoint_bindings = [{
diff --git a/juju/home-maas/06-nova-compute.tf b/juju/home-maas/06-nova-compute.tf
index 6b2c383..a932d84 100644
--- a/juju/home-maas/06-nova-compute.tf
+++ b/juju/home-maas/06-nova-compute.tf
@@ -11,7 +11,7 @@ resource "juju_application" "nova-compute-kvm" {
   units = length(var.compute_ids)
 
   placement = "${join(",", sort([
-    for index, _ in var.compute_ids : 
+    for index, _ in var.compute_ids :
       juju_machine.all_machines[index].machine_id
   ]))}"
 
diff --git a/juju/home-maas/07-controllers.tf b/juju/home-maas/07-controllers.tf
index b4ae5d1..20743b6 100644
--- a/juju/home-maas/07-controllers.tf
+++ b/juju/home-maas/07-controllers.tf
@@ -13,7 +13,7 @@ resource "juju_application" "controller-server" {
   units = length(var.controller_ids)
 
   placement = "${join(",", sort([
-    for index, _ in var.controller_ids : 
+    for index, _ in var.controller_ids :
       juju_machine.all_machines[index].machine_id
   ]))}"
 }
diff --git a/juju/home-maas/08-neutron.tf b/juju/home-maas/08-neutron.tf
index c5b9b3f..94045d7 100644
--- a/juju/home-maas/08-neutron.tf
+++ b/juju/home-maas/08-neutron.tf
@@ -11,8 +11,8 @@ resource "juju_application" "neutron-gateway" {
   units = var.num_units
 
   placement = "${join(",", sort([
-    for index, _ in slice(var.controller_ids, 0, var.num_units+1) : 
-        juju_machine.neutron-api[index].machine_id
+    for index, _ in slice(var.controller_ids, 0, var.num_units+1) :
+        juju_machine.all_machines[index].machine_id
   ]))}"
 
 
@@ -47,8 +47,8 @@ resource "juju_application" "neutron-api" {
   units = var.num_units
 
   placement = "${join(",", sort([
-    for index, _ in slice(var.controller_ids, 0, var.num_units+1) : 
-        juju_machine.neutron-api[index].machine_id
+    for res in juju_machine.neutron-api :
+        res.machine_id
   ]))}"
 
   endpoint_bindings = [{
diff --git a/juju/home-maas/10-vault.tf b/juju/home-maas/10-vault.tf
index 8e245aa..098b927 100644
--- a/juju/home-maas/10-vault.tf
+++ b/juju/home-maas/10-vault.tf
@@ -1,16 +1,7 @@
-resource "juju_machine" "vault-1" {
+resource "juju_machine" "vault" {
+  count       = var.num_units
   model       = var.model-name
-  placement   = join(":",["lxd",juju_machine.all_machines["400"].machine_id])
-  constraints = "spaces=oam"
-}
-resource "juju_machine" "vault-2" {
-  model       = var.model-name
-  placement   = join(":",["lxd",juju_machine.all_machines["401"].machine_id])
-  constraints = "spaces=oam"
-}
-resource "juju_machine" "vault-3" {
-  model       = var.model-name
-  placement   = join(":",["lxd",juju_machine.all_machines["402"].machine_id])
+  placement   = join(":",["lxd",juju_machine.all_machines[var.sdn_ids[count.index+var.num_units]].machine_id])
   constraints = "spaces=oam"
 }
 
@@ -25,12 +16,11 @@ resource "juju_application" "vault" {
     base    = var.default-base
   }
 
-  units = 3
+  units = var.num_units
 
   placement = "${join(",",sort([
-    juju_machine.vault-1.machine_id,
-    juju_machine.vault-2.machine_id,
-    juju_machine.vault-3.machine_id,
+    for res in juju_machine.vault :
+      res.machine_id
   ]))}"
 
   config = {
@@ -83,19 +73,10 @@ resource "juju_application" "hacluster-vault" {
 }
 
 
-resource "juju_machine" "etcd-1" {
+resource "juju_machine" "etcd" {
+  count       = var.num_units
   model       = var.model-name
-  placement   = join(":",["lxd",juju_machine.all_machines["400"].machine_id])
-  constraints = "spaces=oam"
-}
-resource "juju_machine" "etcd-2" {
-  model       = var.model-name
-  placement   = join(":",["lxd",juju_machine.all_machines["401"].machine_id])
-  constraints = "spaces=oam"
-}
-resource "juju_machine" "etcd-3" {
-  model       = var.model-name
-  placement   = join(":",["lxd",juju_machine.all_machines["402"].machine_id])
+  placement   = join(":",["lxd",juju_machine.all_machines[var.sdn_ids[count.index+var.num_units]].machine_id])
   constraints = "spaces=oam"
 }
 
@@ -112,9 +93,8 @@ resource "juju_application" "etcd" {
   }
 
   placement = "${join(",",sort([
-    juju_machine.etcd-1.machine_id,
-    juju_machine.etcd-2.machine_id,
-    juju_machine.etcd-3.machine_id,
+    for res in juju_machine.etcd :
+      res.machine_id
   ]))}"
 
   endpoint_bindings = [{