Extract etcd membership validation into a separate phase

action/apply.go

@@ -61,6 +61,7 @@ func NewApply(opts ApplyOptions) *Apply {
 			&phase.ValidateHosts{},
 			&phase.GatherK0sFacts{},
 			&phase.ValidateFacts{SkipDowngradeCheck: opts.DisableDowngradeCheck},
+			&phase.ValidateEtcdMembers{},
 
 			// if UploadBinaries: true
 			&phase.DownloadBinaries{}, // downloads k0s binaries to local cache

phase/validate_etcd_members.go

@@ -0,0 +1,90 @@
+package phase
+
+import (
+	"fmt"
+	"slices"
+
+	"github.com/k0sproject/k0sctl/pkg/apis/k0sctl.k0sproject.io/v1beta1"
+	"github.com/k0sproject/k0sctl/pkg/apis/k0sctl.k0sproject.io/v1beta1/cluster"
+	log "github.com/sirupsen/logrus"
+)
+
+// ValidateEtcdMembers checks for existing etcd members with the same IP as a new controller
+type ValidateEtcdMembers struct {
+	GenericPhase
+	hosts cluster.Hosts
+}
+
+// Title for the phase
+func (p *ValidateEtcdMembers) Title() string {
+	return "Validate etcd members"
+}
+
+// Prepare the phase
+func (p *ValidateEtcdMembers) Prepare(config *v1beta1.Cluster) error {
+	p.Config = config
+	p.hosts = p.Config.Spec.Hosts.Controllers().Filter(func(h *cluster.Host) bool {
+		return h.Metadata.K0sRunningVersion == nil // only check new controllers
+	})
+
+	return nil
+}
+
+// ShouldRun is true when there are new controllers and etcd
+func (p *ValidateEtcdMembers) ShouldRun() bool {
+	if p.Config.Spec.K0sLeader().Metadata.K0sRunningVersion == nil {
+		log.Debugf("%s: leader has no k0s running, assuming a fresh cluster", p.Config.Spec.K0sLeader())
+		return false
+	}
+
+	if p.Config.Spec.K0sLeader().Role == "single" {
+		log.Debugf("%s: leader is a single node, assuming no etcd", p.Config.Spec.K0sLeader())
+		return false
+	}
+
+	if len(p.Config.Spec.K0s.Config) > 0 {
+		storageType := p.Config.Spec.K0s.Config.DigString("spec", "storage", "type")
+		if storageType != "" && storageType != "etcd" {
+			log.Debugf("%s: storage type is %q, not k0s managed etcd", p.Config.Spec.K0sLeader(), storageType)
+			return false
+		}
+	}
+	return len(p.hosts) > 0
+}
+
+// Run the phase
+func (p *ValidateEtcdMembers) Run() error {
+	if err := p.validateControllerSwap(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (p *ValidateEtcdMembers) validateControllerSwap() error {
+	if len(p.Config.Metadata.EtcdMembers) > len(p.Config.Spec.Hosts.Controllers()) {
+		log.Warnf("there are more etcd members in the cluster than controllers listed in the configuration")
+	}
+
+	for _, h := range p.hosts {
+		log.Debugf("%s: host is new, checking if etcd members list already contains %s", h, h.PrivateAddress)
+		if slices.Contains(p.Config.Metadata.EtcdMembers, h.PrivateAddress) {
+			if Force {
+				log.Infof("%s: force used, running 'k0s etcd leave' for the host", h)
+				leader := p.Config.Spec.K0sLeader()
+				leaveCommand := leader.Configurer.K0sCmdf("etcd leave --peer-address %s", h.PrivateAddress)
+				err := p.Wet(h, fmt.Sprintf("remove host from etcd using %v", leaveCommand), func() error {
+					return leader.Exec(leaveCommand)
+				})
+				if err != nil {
+					return fmt.Errorf("controller %s is listed as an existing etcd member but k0s is not found installed on it, the host may have been replaced. attempted etcd leave for the address %s but it failed: %w", h, h.PrivateAddress, err)
+				}
+				continue
+			}
+			return fmt.Errorf("controller %s is listed as an existing etcd member but k0s is not found installed on it, the host may have been replaced. check the host and use `k0s etcd leave --peer-address %s on a controller or re-run apply with --force", h, h.PrivateAddress)
+		}
+		log.Debugf("%s: no match, assuming its safe to install", h)
+	}
+
+	return nil
+}

phase/validate_facts.go

@@ -2,7 +2,6 @@ package phase
 
 import (
 	"fmt"
-	"slices"
 
 	log "github.com/sirupsen/logrus"
 )
@@ -28,10 +27,6 @@ func (p *ValidateFacts) Run() error {
 		return err
 	}
 
-	if err := p.validateControllerSwap(); err != nil {
-		return err
-	}
-
 	return nil
 }
 
@@ -74,47 +69,3 @@ func (p *ValidateFacts) validateDefaultVersion() error {
 
 	return nil
 }
-
-func (p *ValidateFacts) validateControllerSwap() error {
-	log.Debugf("validating controller list vs etcd member list")
-	if p.Config.Spec.K0sLeader().Metadata.K0sRunningVersion == nil {
-		log.Debugf("%s: leader has no k0s running, assuming a fresh cluster", p.Config.Spec.K0sLeader())
-		return nil
-	}
-
-	if p.Config.Spec.K0sLeader().Role == "single" {
-		log.Debugf("%s: leader is a single node, assuming no etcd", p.Config.Spec.K0sLeader())
-		return nil
-	}
-
-	if len(p.Config.Metadata.EtcdMembers) > len(p.Config.Spec.Hosts.Controllers()) {
-		log.Warnf("there are more etcd members in the cluster than controllers listed in the k0sctl configuration")
-	}
-
-	for _, h := range p.Config.Spec.Hosts.Controllers() {
-		if h.Metadata.K0sRunningVersion != nil {
-			log.Debugf("%s: host has k0s running, no need to check if it was replaced", h)
-			continue
-		}
-
-		log.Debugf("%s: host is new, checking if etcd members list already contains %s", h, h.PrivateAddress)
-		if slices.Contains(p.Config.Metadata.EtcdMembers, h.PrivateAddress) {
-			if Force {
-				log.Infof("%s: force used, running 'k0s etcd leave' for the host", h)
-				leader := p.Config.Spec.K0sLeader()
-				leaveCommand := leader.Configurer.K0sCmdf("etcd leave --peer-address %s", h.PrivateAddress)
-				err := p.Wet(h, fmt.Sprintf("remove host from etcd using %v", leaveCommand), func() error {
-					return leader.Exec(leaveCommand)
-				})
-				if err != nil {
-					return fmt.Errorf("controller %s is listed as an existing etcd member but k0s is not found installed on it, the host may have been replaced. attempted etcd leave for the address %s but it failed: %w", h, h.PrivateAddress, err)
-				}
-				continue
-			}
-			return fmt.Errorf("controller %s is listed as an existing etcd member but k0s is not found installed on it, the host may have been replaced. check the host and use `k0s etcd leave --peer-address %s on a controller or re-run apply with --force", h, h.PrivateAddress)
-		}
-		log.Debugf("%s: no match, assuming its safe to install", h)
-	}
-
-	return nil
-}