use yamlencode for k3s configs...

...and remove the now, hopefully unneeded workaround for
agent.conf, all values are in config.yaml now

agents.tf

@@ -59,27 +59,15 @@ resource "hcloud_server" "agents" {
     EOT
   }
 
-  # Generating and uploading the angent.conf file
-  provisioner "file" {
-    content = templatefile("${path.module}/templates/agent.conf.tpl", {
-      server_url = "https://${local.first_control_plane_network_ip}:6443"
-      node_token = random_password.k3s_token.result
-    })
-    destination = "/etc/rancher/k3s/agent.conf"
-
-    connection {
-      user           = "root"
-      private_key    = local.ssh_private_key
-      agent_identity = local.ssh_identity
-      host           = self.ipv4_address
-    }
-  }
-
   # Generating k3s server config file
   provisioner "file" {
-    content = templatefile("${path.module}/templates/agent_config.yaml.tpl", {
-      node_ip   = cidrhost(hcloud_network.k3s.ip_range, 2 + var.servers_num + count.index)
-      node_name = self.name
+    content = yamlencode({
+      node-name     = self.name
+      server        = "https://${local.first_control_plane_network_ip}:6443"
+      kubelet-arg   = "cloud-provider=external"
+      flannel-iface = "eth1"
+      node-ip       = local.first_control_plane_network_ip
+      token         = random_password.k3s_token.result
     })
     destination = "/etc/rancher/k3s/config.yaml"
 

master.tf

@@ -59,11 +59,16 @@ resource "hcloud_server" "first_control_plane" {
 
   # Generating k3s master config file
   provisioner "file" {
-    content = templatefile("${path.module}/templates/master_config.yaml.tpl", {
-      node_ip                           = local.first_control_plane_network_ip
+    content = yamlencode({
+      node-name                = self.name
+      cluster-init             = true
+      disable-cloud-controller = true
+      disable                  = "servicelb, local-storage"
+      flannel-iface            = "eth1"
+      kubelet-arg              = "cloud-provider=external"
+      node-ip                  = local.first_control_plane_network_ip
+      advertise-address        = local.first_control_plane_network_ip
       token                    = random_password.k3s_token.result
-      node_name                         = self.name
-      allow_scheduling_on_control_plane = var.allow_scheduling_on_control_plane
     })
     destination = "/etc/rancher/k3s/config.yaml"
 

servers.tf

@@ -60,12 +60,18 @@ resource "hcloud_server" "control_planes" {
 
   # Generating k3s server config file
   provisioner "file" {
-    content = templatefile("${path.module}/templates/server_config.yaml.tpl", {
-      first_control_plane_url           = "https://${local.first_control_plane_network_ip}:6443"
-      node_ip                           = cidrhost(hcloud_network.k3s.ip_range, 3 + count.index)
+    content = yamlencode({
+      node-name                = self.name
+      server                   = "https://${local.first_control_plane_network_ip}:6443"
+      cluster-init             = true
+      disable-cloud-controller = true
+      disable                  = "servicelb, local-storage"
+      flannel-iface            = "eth1"
+      kubelet-arg              = "cloud-provider=external"
+      node-ip                  = cidrhost(hcloud_network.k3s.ip_range, 3 + count.index)
+      advertise-address        = cidrhost(hcloud_network.k3s.ip_range, 3 + count.index)
+      tls-san                  = cidrhost(hcloud_network.k3s.ip_range, 3 + count.index)
       token                    = random_password.k3s_token.result
-      node_name                         = self.name
-      allow_scheduling_on_control_plane = var.allow_scheduling_on_control_plane
     })
     destination = "/etc/rancher/k3s/config.yaml"
 

templates/agent.conf.tpl

@@ -1,3 +0,0 @@
-SERVER_URL="${server_url}"
-NODE_TOKEN="${node_token}"
-AGENT_OPTS=

templates/agent_config.yaml.tpl

@@ -1,4 +0,0 @@
-node-ip: ${node_ip}
-kubelet-arg: "cloud-provider=external"
-flannel-iface: eth1
-node-name: ${node_name}

templates/master_config.yaml.tpl

@@ -1,16 +0,0 @@
-cluster-init: true
-disable-cloud-controller: true
-disable:
-- servicelb
-- local-storage
-flannel-iface: eth1
-node-ip: ${node_ip}
-advertise-address: ${node_ip}
-tls-san: ${node_ip}
-kubelet-arg: "cloud-provider=external"
-token: ${token}
-node-name: ${node_name}
-%{ if !allow_scheduling_on_control_plane }
-node-taint:
-- node-role.kubernetes.io/master:NoSchedule
-%{ endif }

templates/server_config.yaml.tpl

@@ -1,16 +0,0 @@
-server: ${first_control_plane_url}
-disable-cloud-controller: true
-disable:
-- servicelb
-- local-storage
-flannel-iface: eth1
-node-ip: ${node_ip}
-advertise-address: ${node_ip}
-tls-san: ${node_ip}
-kubelet-arg: "cloud-provider=external"
-token: ${token}
-node-name: ${node_name}
-%{ if !allow_scheduling_on_control_plane }
-node-taint:
-- node-role.kubernetes.io/master:NoSchedule
-%{ endif }