Add worker multinode join implementation (#14)

bootstrap/controllers/ck8sconfig_controller.go

@@ -298,10 +298,20 @@ func (r *CK8sConfigReconciler) joinWorker(ctx context.Context, scope *Scope) err
 		conditions.MarkFalse(scope.Config, bootstrapv1.DataSecretAvailableCondition, bootstrapv1.DataSecretGenerationFailedReason, clusterv1.ConditionSeverityWarning, err.Error())
 		return err
 	}
-	// TODO(neoaggelos): Use authToken to reach the existing k8sd control plane nodes through the k8sd proxy, and generate a token for this node.
-	_ = authToken
-	joinToken := "replace me"
-	// joinToken, err := ck8s.NewControlPlaneJoinToken(ctx, r.Client, authToken, ...)
+
+	if authToken == nil {
+		return fmt.Errorf("auth token not yet generated")
+	}
+
+	workloadCluster, err := r.managementCluster.GetWorkloadCluster(ctx, util.ObjectKey(scope.Cluster))
+	if err != nil {
+		return fmt.Errorf("failed to create remote cluster client: %w", err)
+	}
+
+	joinToken, err := workloadCluster.NewWorkerJoinToken(ctx, *authToken, scope.Config.Spec.ControlPlaneConfig.MicroclusterPort, scope.Config.Name)
+	if err != nil {
+		return fmt.Errorf("failed to request join token: %w", err)
+	}
 
 	configStruct := ck8s.GenerateJoinWorkerConfig(ck8s.JoinWorkerConfig{})
 	joinConfig, err := kubeyaml.Marshal(configStruct)

pkg/ck8s/workload_cluster.go

@@ -44,6 +44,7 @@ type WorkloadCluster interface {
 	UpdateAgentConditions(ctx context.Context, controlPlane *ControlPlane)
 	UpdateEtcdConditions(ctx context.Context, controlPlane *ControlPlane)
 	NewControlPlaneJoinToken(ctx context.Context, authToken string, microclusterPort int, name string) (string, error)
+	NewWorkerJoinToken(ctx context.Context, authToken string, microclusterPort int, name string) (string, error)
 
 	// NOTE(neoaggelos): See notes in (*CK8sControlPlaneReconciler).reconcileEtcdMembers
 	//
@@ -195,6 +196,12 @@ func (w *Workload) NewControlPlaneJoinToken(ctx context.Context, authToken strin
 	return w.requestJoinToken(ctx, microclusterPort, authToken, name, false)
 }
 
+// NewWorkerJoinToken creates a new join token for a worker node.
+// NewWorkerJoinToken reaches out to the control-plane of the workload cluster via k8sd-proxy client.
+func (w *Workload) NewWorkerJoinToken(ctx context.Context, authToken string, microclusterPort int, name string) (string, error) {
+	return w.requestJoinToken(ctx, microclusterPort, authToken, name, true)
+}
+
 // requestJoinToken requests a join token from the existing control-plane nodes via the k8sd proxy.
 func (w *Workload) requestJoinToken(ctx context.Context, microclusterPort int, authToken string, name string, worker bool) (string, error) {
 	// FIXME: We need to check the default value for this port in one place, not in multiple places.

pkg/cloudinit/worker_join.go

@@ -48,6 +48,7 @@ func NewJoinWorker(input JoinWorkerInput) (CloudConfig, error) {
 	config.RunCommands = append(config.RunCommands,
 		"/capi/scripts/load-images.sh",
 		"/capi/scripts/join-cluster.sh",
+		"/capi/scripts/create-sentinel-bootstrap.sh",
 	)
 	config.RunCommands = append(config.RunCommands, input.PostRunCommands...)
 

pkg/cloudinit/worker_join_test.go

@@ -0,0 +1,44 @@
+package cloudinit_test
+
+import (
+	"testing"
+
+	. "github.com/onsi/gomega"
+
+	"github.com/canonical/cluster-api-k8s/pkg/cloudinit"
+)
+
+func TestNewJoinWorker(t *testing.T) {
+	g := NewWithT(t)
+
+	config, err := cloudinit.NewJoinWorker(cloudinit.JoinWorkerInput{
+		BaseUserData: cloudinit.BaseUserData{
+			KubernetesVersion: "v1.30.0",
+			BootCommands:      []string{"bootcmd"},
+			PreRunCommands:    []string{"prerun1", "prerun2"},
+			PostRunCommands:   []string{"postrun1", "postrun2"},
+			ExtraFiles: []cloudinit.File{{
+				Path:        "/tmp/file",
+				Content:     "test file",
+				Permissions: "0400",
+				Owner:       "root:root",
+			}},
+			ConfigFileContents:  "### config file ###",
+			MicroclusterAddress: ":2380",
+		},
+	})
+
+	// TODO: add tests for expected files and commands
+	g.Expect(err).To(BeNil())
+	g.Expect(config.RunCommands).To(Equal([]string{
+		"set -x",
+		"prerun1",
+		"prerun2",
+		"/capi/scripts/install.sh",
+		"/capi/scripts/load-images.sh",
+		"/capi/scripts/join-cluster.sh",
+		"/capi/scripts/create-sentinel-bootstrap.sh",
+		"postrun1",
+		"postrun2",
+	}))
+}