fixed single node cluster

README.md

@@ -170,14 +170,9 @@ spec:
 
 <summary>Single-node cluster</summary>
 
-Running a development cluster on a single node, without any high-availability is possible as well.
+Running a development cluster on a single node, without any high-availability is possible as well. You need one control plane nodepool with a count of 1, and one agent nodepool with a count of 0.
-In this case, we don't deploy an external load-balancer, but use [k3s service load balancer](https://rancher.com/docs/k3s/latest/en/networking/#service-load-balancer) on the host itself and open up port 80 & 443 in the firewall.
 
-``` terraform
+In this case, we don't deploy an external load-balancer, but use the default [k3s service load balancer](https://rancher.com/docs/k3s/latest/en/networking/#service-load-balancer) on the host itself and open up port 80 & 443 in the firewall (done automatically).
-control_plane_count = 1
-allow_scheduling_on_control_plane = true
-agent_nodepools = []
-```
 
 </details>
 

control_planes.tf

@@ -46,7 +46,7 @@ resource "null_resource" "control_planes" {
   provisioner "file" {
     content = yamlencode({
       node-name                = module.control_planes[each.key].name
-      server                   = "https://${module.control_planes[each.key].private_ipv4_address == module.control_planes[keys(module.control_planes)[0]].private_ipv4_address && length(module.control_planes) > 1 ? module.control_planes[keys(module.control_planes)[1]].private_ipv4_address : module.control_planes[keys(module.control_planes)[0]].private_ipv4_address}:6443"
+      server                   = length(module.control_planes) == 1 ? null : "https://${module.control_planes[each.key].private_ipv4_address == module.control_planes[keys(module.control_planes)[0]].private_ipv4_address ? module.control_planes[keys(module.control_planes)[1]].private_ipv4_address : module.control_planes[keys(module.control_planes)[0]].private_ipv4_address}:6443"
       token                    = random_password.k3s_token.result
       disable-cloud-controller = true
       disable                  = local.disable_extras
@@ -54,7 +54,6 @@ resource "null_resource" "control_planes" {
       kubelet-arg              = "cloud-provider=external"
       node-ip                  = module.control_planes[each.key].private_ipv4_address
       advertise-address        = module.control_planes[each.key].private_ipv4_address
-      tls-san                  = module.control_planes[each.key].ipv4_address
       node-label               = each.value.labels
       node-taint               = each.value.taints
     })

init.tf

@@ -18,7 +18,6 @@ resource "null_resource" "first_control_plane" {
       kubelet-arg              = "cloud-provider=external"
       node-ip                  = module.control_planes[keys(module.control_planes)[0]].private_ipv4_address
       advertise-address        = module.control_planes[keys(module.control_planes)[0]].private_ipv4_address
-      tls-san                  = module.control_planes[keys(module.control_planes)[0]].ipv4_address
       node-taint               = local.control_plane_nodepools[keys(module.control_planes)[0]].taints
       node-label               = local.control_plane_nodepools[keys(module.control_planes)[0]].labels
     })

locals.tf

@@ -211,6 +211,8 @@ locals {
   default_agent_labels         = concat([], var.automatically_upgrade_k3s ? ["k3s_upgrade=true"] : [])
   default_control_plane_labels = concat([], var.automatically_upgrade_k3s ? ["k3s_upgrade=true"] : [])
 
+  allow_scheduling_on_control_plane = local.is_single_node_cluster ? true : var.allow_scheduling_on_control_plane
+
   # Default k3s node taints
-  default_control_plane_taints = concat([], var.allow_scheduling_on_control_plane ? [] : ["node-role.kubernetes.io/master:NoSchedule"])
+  default_control_plane_taints = concat([], local.allow_scheduling_on_control_plane ? [] : ["node-role.kubernetes.io/master:NoSchedule"])
 }

output.tf

@@ -19,7 +19,9 @@ output "agents_public_ipv4" {
 
 output "load_balancer_public_ipv4" {
   description = "The public IPv4 address of the Hetzner load balancer"
-  value       = local.is_single_node_cluster ? module.control_planes[0].ipv4_address : var.traefik_enabled == false ? null : data.hcloud_load_balancer.traefik[0].ipv4
+  value = local.is_single_node_cluster ? [
+    for obj in module.control_planes : obj.ipv4_address
+  ][0] : var.traefik_enabled == false ? null : data.hcloud_load_balancer.traefik[0].ipv4
 }
 
 output "kubeconfig_file" {

terraform.tfvars.example

@@ -29,7 +29,8 @@ network_region   = "eu-central" # change to `us-east` if location is ash
 # Also, before decreasing the count of any nodepools to 0, it's important to drain and cordon it the nodes in question, otherwise it will leave your cluster in a bad state.
 
 # Before initializing the cluster, you can change all parameters and add or remove any nodepools.
-# If you want to have a single node cluster, just have 1 control plane nodepools with a count of 1.
+
+# If you want to have a single node cluster, just have 1 control plane nodepools with a count of 1, and one agent nodepool with a count of 0.
 
 # Example below:
 
@@ -59,7 +60,7 @@ agent_nodepools = [
     location    = "fsn1",
     labels      = [],
     taints      = [],
-    count       = 2
+    count       = 1
   },
   {
     name        = "agent-large",
@@ -106,7 +107,7 @@ load_balancer_location = "fsn1"
 # metrics_server_enabled = false
 
 # If you want to allow non-control-plane workloads to run on the control-plane nodes set "true" below. The default is "false".
-# Also good for single node clusters.
+# True by default for single node clusters.
 # allow_scheduling_on_control_plane = true
 
 # If you want to disable automatic upgrade of k3s, you can set this to false, default is "true".