use FelixConfiguration.CgroupV2Path to set CALICO_CGROUP_PATH

Read the CgroupV2Path value from FelixConfiguration and set it as env
var for the mount-bpffs node's init container.

pkg/controller/installation/core_controller.go

@@ -1359,6 +1359,7 @@ func (r *ReconcileInstallation) Reconcile(ctx context.Context, request reconcile
 		Terminating:             nodeTerminating,
 		PrometheusServerTLS:     nodePrometheusTLS,
 		FelixHealthPort:         *felixConfiguration.Spec.HealthPort,
+		NodeCgroupV2Path:        felixConfiguration.Spec.CgroupV2Path,
 		BindMode:                bgpConfiguration.Spec.BindMode,
 		UsePSP:                  r.usePSP,
 	}

pkg/render/node.go

@@ -119,6 +119,10 @@ type NodeConfiguration struct {
 	// and sets this.
 	FelixHealthPort int
 
+	// Node's BPFFsMountDir override. The controller reads FelixConfiguration
+	// and sets this.
+	NodeBPFFsMountDir string
+
 	// The bindMode read from the default BGPConfiguration. Used to trigger rolling updates
 	// should this value change.
 	BindMode string
@@ -1193,6 +1197,7 @@ func (c *nodeComponent) flexVolumeContainer() corev1.Container {
 // mounted on the host itself, otherwise, a restart of the node container would tear down the mount and destroy
 // the BPF dataplane's BPF maps.
 func (c *nodeComponent) bpffsInitContainer() corev1.Container {
+	bpffsEnv := c.bpffsEnvVars()
 	bidirectional := corev1.MountPropagationBidirectional
 	mounts := []corev1.VolumeMount{
 		{
@@ -1221,11 +1226,25 @@ func (c *nodeComponent) bpffsInitContainer() corev1.Container {
 		Image:           c.nodeImage,
 		ImagePullPolicy: ImagePullPolicy(),
 		Command:         []string{CalicoNodeObjectName, "-init"},
+		Env:             bpffsEnv,
 		SecurityContext: securitycontext.NewRootContext(true),
 		VolumeMounts:    mounts,
 	}
 }
 
+// bpffsEnvVars creates the mount-bpffs container's envvars.
+func (c *nodeComponent) bpffsEnvVars() []corev1.EnvVar {
+	envVars := []corev1.EnvVar{}
+
+	if c.bpfDataplaneEnabled() {
+		if c.cfg.Installation.CustomCgroupPath != "" {
+			envVars = append(envVars, corev1.EnvVar{Name: "CALICO_CGROUP_PATH", Value: c.cfg.Installation.CustomCgroupPath})
+		}
+	}
+
+	return envVars
+}
+
 // cniEnvvars creates the CNI container's envvars.
 func (c *nodeComponent) cniEnvvars() []corev1.EnvVar {
 	if c.cfg.Installation.CNI.Type != operatorv1.PluginCalico {