Add spec.hosts.noTaints to disable default controller+worker taints (#…

…390)

README.md

@@ -291,6 +291,10 @@ One of:
 - `single` - a [single-node cluster](https://docs.k0sproject.io/main/k0s-single-node/) host, the configuration can only contain one host
 - `worker` - a worker host
 
+###### `spec.hosts[*].noTaints` <boolean> (optional) (default: `false`)
+
+When `true` and used in conjuction with the `controller+worker` role, the default taints are disabled making regular workloads schedulable on the node. By default, k0s sets a node-role.kubernetes.io/master:NoSchedule taint on controller+worker nodes and only workloads with toleration for it will be scheduled.
+
 ###### `spec.hosts[*].uploadBinary` <boolean> (optional) (default: `false`)
 
 When `true`, the k0s binaries for target host will be downloaded and cached on the local host and uploaded to the target.

phase/gather_k0s_facts.go

@@ -150,6 +150,10 @@ func (p *GatherK0sFacts) investigateK0s(h *cluster.Host) error {
 		}
 	}
 
+	if h.Role == "controller+worker" && !h.NoTaints {
+		log.Warnf("%s: the controller+worker node will not schedule regular workloads without toleration for node-role.kubernetes.io/master:NoSchedule unless 'noTaints: true' is set", h)
+	}
+
 	if h.Metadata.NeedsUpgrade {
 		log.Warnf("%s: k0s will be upgraded", h)
 	}

pkg/apis/k0sctl.k0sproject.io/v1beta1/cluster/host.go

@@ -36,6 +36,7 @@ type Host struct {
 	Files            []*UploadFile     `yaml:"files,omitempty"`
 	OSIDOverride     string            `yaml:"os,omitempty"`
 	HostnameOverride string            `yaml:"hostname,omitempty"`
+	NoTaints         bool              `yaml:"noTaints,omitempty"`
 	Hooks            Hooks             `yaml:"hooks,omitempty"`
 
 	UploadBinaryPath string       `yaml:"-"`
@@ -58,6 +59,10 @@ func (h *Host) SetDefaults() {
 		log.Debugf("%s: changed role from '%s' to 'controller+worker' because of --enable-worker installFlag", h, h.Role)
 		h.Role = "controller+worker"
 	}
+
+	if h.InstallFlags.Get("--no-taints") != "" && h.InstallFlags.GetValue("--no-taints") != "false" {
+		h.NoTaints = true
+	}
 }
 
 func (h *Host) Validate() error {
@@ -71,6 +76,7 @@ func (h *Host) Validate() error {
 		validation.Field(&h.Role, validation.In("controller", "worker", "controller+worker", "single").Error("unknown role "+h.Role)),
 		validation.Field(&h.PrivateAddress, is.IP),
 		validation.Field(&h.Files),
+		validation.Field(&h.NoTaints, validation.When(h.Role != "controller+worker", validation.NotIn(true).Error("noTaints can only be true for controller+worker role"))),
 	)
 }
 
@@ -233,6 +239,9 @@ func (h *Host) K0sInstallCommand() string {
 	case "controller+worker":
 		role = "controller"
 		flags.AddUnlessExist("--enable-worker")
+		if h.NoTaints {
+			flags.AddUnlessExist("--no-taints")
+		}
 	case "single":
 		role = "controller"
 		flags.AddUnlessExist("--single")