From 1b696b1843a87d85d35e51d1cfa318c5c27ee9bc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan-Luis=20de=20Sousa-Valadas=20Casta=C3=B1o?=
 <jvaladas@mirantis.com>
Date: Thu, 2 Jan 2025 12:01:00 +0100
Subject: [PATCH] Allow to disable CPLB load balancer
MIME-Version: 1.0
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This is one of the remaining tasks of #5279. The intended use case for
this is to allow to use the VIPs functionality while using some user
provided load balancer such as HAProxy, nginx, etc...

Signed-off-by: Juan-Luis de Sousa-Valadas Castaño <jvaladas@mirantis.com>
---
 pkg/apis/k0s/v1beta1/cplb.go                    |  3 +++
 pkg/component/controller/cplb/cplb_linux.go     | 17 ++++++++++-------
 .../k0s/k0s.k0sproject.io_clusterconfigs.yaml   |  3 +++
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/pkg/apis/k0s/v1beta1/cplb.go b/pkg/apis/k0s/v1beta1/cplb.go
index f38bdd504a3e..a942d3dda567 100644
--- a/pkg/apis/k0s/v1beta1/cplb.go
+++ b/pkg/apis/k0s/v1beta1/cplb.go
@@ -75,6 +75,9 @@ type KeepalivedSpec struct {
 	// +kubebuilder:validation:Maximum=65535
 	// +optional
 	UserSpaceProxyPort int `json:"userSpaceProxyBindPort,omitempty"`
+	// DisableLoadBalanmcer disables the load balancer.
+	// +optional
+	DisableLoadBalancer bool `json:"disableLoadBalancer,omitempty"`
 }
 
 // VRRPInstances is a list of VRRPInstance
diff --git a/pkg/component/controller/cplb/cplb_linux.go b/pkg/component/controller/cplb/cplb_linux.go
index 0496ffa08c48..24c54a4c58ad 100644
--- a/pkg/component/controller/cplb/cplb_linux.go
+++ b/pkg/component/controller/cplb/cplb_linux.go
@@ -100,13 +100,15 @@ func (k *Keepalived) Start(ctx context.Context) error {
 		}
 	}
 
-	if len(k.Config.VRRPInstances) > 0 || len(k.Config.VirtualServers) > 0 {
-		k.log.Info("Starting CPLB reconciler")
-		updateCh := make(chan struct{}, 1)
-		k.reconciler = NewCPLBReconciler(k.KubeConfigPath, updateCh)
-		k.updateCh = updateCh
-		if err := k.reconciler.Start(); err != nil {
-			return fmt.Errorf("failed to start CPLB reconciler: %w", err)
+	if !k.Config.DisableLoadBalancer {
+		if len(k.Config.VRRPInstances) > 0 || len(k.Config.VirtualServers) > 0 {
+			k.log.Info("Starting CPLB reconciler")
+			updateCh := make(chan struct{}, 1)
+			k.reconciler = NewCPLBReconciler(k.KubeConfigPath, updateCh)
+			k.updateCh = updateCh
+			if err := k.reconciler.Start(); err != nil {
+				return fmt.Errorf("failed to start CPLB reconciler: %w", err)
+			}
 		}
 	}
 
@@ -160,6 +162,7 @@ func (k *Keepalived) Start(ctx context.Context) error {
 			}
 		}()
 	}
+
 	return k.supervisor.Supervise()
 }
 
diff --git a/static/_crds/k0s/k0s.k0sproject.io_clusterconfigs.yaml b/static/_crds/k0s/k0s.k0sproject.io_clusterconfigs.yaml
index a9a3da692bb7..b1fc5d6f6cc7 100644
--- a/static/_crds/k0s/k0s.k0sproject.io_clusterconfigs.yaml
+++ b/static/_crds/k0s/k0s.k0sproject.io_clusterconfigs.yaml
@@ -508,6 +508,9 @@ spec:
                           Keepalived contains configuration options related to the "Keepalived" type
                           of load balancing.
                         properties:
+                          disableLoadBalancer:
+                            description: DisableLoadBalanmcer disables the load balancer.
+                            type: boolean
                           userSpaceProxyBindPort:
                             default: 6444
                             description: |-