try fetching server before creating

pkg/provider/core.go

@@ -18,6 +18,13 @@ import (
 	"k8s.io/klog/v2"
 )
 
+const (
+	StackitProviderName      = "stackit"
+	StackitMachineLabel      = "mcm.gardener.cloud/machine"
+	StackitMachineClassLabel = "mcm.gardener.cloud/machineclass"
+	StackitRoleLabel         = "mcm.gardener.cloud/role"
+)
+
 // CreateMachine handles a machine creation request by creating a STACKIT server
 //
 // This method creates a new server in STACKIT infrastructure based on the ProviderSpec
@@ -38,6 +45,12 @@ func (p *Provider) CreateMachine(ctx context.Context, req *driver.CreateMachineR
 	klog.V(2).Infof("Machine creation request has been received for %q", req.Machine.Name)
 	defer klog.V(2).Infof("Machine creation request has been processed for %q", req.Machine.Name)
 
+	// Check if incoming provider in the MachineClass is a provider we support
+	if req.MachineClass.Provider != StackitProviderName {
+		err := fmt.Errorf("requested for Provider '%s', we only support '%s'", req.MachineClass.Provider, StackitProviderName)
+		return nil, status.Error(codes.InvalidArgument, err.Error())
+	}
+
 	// Decode ProviderSpec from MachineClass
 	providerSpec, err := decodeProviderSpec(req.MachineClass)
 	if err != nil {
@@ -68,9 +81,9 @@ func (p *Provider) CreateMachine(ctx context.Context, req *driver.CreateMachineR
 		}
 	}
 	// Add MCM-specific labels for server identification and orphan VM detection
-	labels["mcm.gardener.cloud/machine"] = req.Machine.Name
-	labels["mcm.gardener.cloud/machineclass"] = req.MachineClass.Name
-	labels["mcm.gardener.cloud/role"] = "node"
+	labels[StackitMachineLabel] = req.Machine.Name
+	labels[StackitMachineClassLabel] = req.MachineClass.Name
+	labels[StackitRoleLabel] = "node"
 
 	// Create server request
 	createReq := &CreateServerRequest{
@@ -177,7 +190,7 @@ func (p *Provider) CreateMachine(ctx context.Context, req *driver.CreateMachineR
 	}
 
 	// Generate ProviderID in format: stackit://<projectId>/<serverId>
-	providerID := fmt.Sprintf("stackit://%s/%s", projectID, server.ID)
+	providerID := fmt.Sprintf("%s://%s/%s", StackitProviderName, projectID, server.ID)
 
 	// NodeName is the machine name (will register with this name in Kubernetes)
 	nodeName := req.Machine.Name
@@ -351,7 +364,8 @@ func (p *Provider) ListMachines(ctx context.Context, req *driver.ListMachinesReq
 	}
 
 	// Call STACKIT API to list all servers
-	servers, err := p.client.ListServers(ctx, projectID, providerSpec.Region)
+	labelSelector := fmt.Sprintf("%s=%s", StackitMachineClassLabel, req.MachineClass.Name)
+	servers, err := p.client.ListServers(ctx, projectID, providerSpec.Region, labelSelector)
 	if err != nil {
 		klog.Errorf("Failed to list servers for MachineClass %q: %v", req.MachineClass.Name, err)
 		return nil, status.Error(codes.Internal, fmt.Sprintf("failed to list servers: %v", err))
@@ -361,26 +375,16 @@ func (p *Provider) ListMachines(ctx context.Context, req *driver.ListMachinesReq
 	// We use the "mcm.gardener.cloud/machineclass" label to identify which servers belong to this MachineClass
 	machineList := make(map[string]string)
 	for _, server := range servers {
-		// Skip servers without labels
-		if server.Labels == nil {
-			continue
-		}
+		// Generate ProviderID in format: stackit://<projectId>/<serverId>
+		providerID := fmt.Sprintf("stackit://%s/%s", projectID, server.ID)
 
-		// Check if server has the matching MachineClass label
-		if machineClassLabel, ok := server.Labels["mcm.gardener.cloud/machineclass"]; ok {
-			if machineClassLabel == req.MachineClass.Name {
-				// Generate ProviderID in format: stackit://<projectId>/<serverId>
-				providerID := fmt.Sprintf("stackit://%s/%s", projectID, server.ID)
-
-				// Get machine name from labels (fallback to server name if not found)
-				machineName := server.Name
-				if machineLabel, ok := server.Labels["mcm.gardener.cloud/machine"]; ok {
-					machineName = machineLabel
-				}
-
-				machineList[providerID] = machineName
-			}
+		// Get machine name from labels (fallback to server name if not found)
+		machineName := server.Name
+		if machineLabel, ok := server.Labels[StackitMachineLabel]; ok {
+			machineName = machineLabel
 		}
+
+		machineList[providerID] = machineName
 	}
 
 	klog.V(2).Infof("Found %d machines for MachineClass %q", len(machineList), req.MachineClass.Name)

pkg/provider/core_create_machine_basic_test.go

@@ -60,6 +60,7 @@ var _ = Describe("CreateMachine", func() {
 			ObjectMeta: metav1.ObjectMeta{
 				Name: "test-machine-class",
 			},
+			Provider: "stackit",
 			ProviderSpec: runtime.RawExtension{
 				Raw: providerSpecRaw,
 			},
@@ -148,6 +149,15 @@ var _ = Describe("CreateMachine", func() {
 			Expect(ok).To(BeTrue())
 			Expect(statusErr.Code()).To(Equal(codes.InvalidArgument))
 		})
+
+		It("should fail when Provider is wrong", func() {
+			req.MachineClass.Provider = "openstack"
+
+			_, err := provider.CreateMachine(ctx, req)
+
+			Expect(err).To(HaveOccurred())
+			Expect(err.Error()).To(ContainSubstring("requested for Provider 'openstack', we only support 'stackit'"))
+		})
 	})
 
 	Context("with invalid Secret", func() {

pkg/provider/core_create_machine_config_test.go

@@ -57,6 +57,7 @@ var _ = Describe("CreateMachine", func() {
 			ObjectMeta: metav1.ObjectMeta{
 				Name: "test-machine-class",
 			},
+			Provider: "stackit",
 			ProviderSpec: runtime.RawExtension{
 				Raw: providerSpecRaw,
 			},

pkg/provider/core_create_machine_networking_test.go

@@ -68,6 +68,7 @@ var _ = Describe("CreateMachine - Networking", func() {
 				ObjectMeta: metav1.ObjectMeta{
 					Name: "test-machine-class",
 				},
+				Provider: "stackit",
 				ProviderSpec: runtime.RawExtension{
 					Raw: providerSpecRaw,
 				},
@@ -115,6 +116,7 @@ var _ = Describe("CreateMachine - Networking", func() {
 				ObjectMeta: metav1.ObjectMeta{
 					Name: "test-machine-class",
 				},
+				Provider: "stackit",
 				ProviderSpec: runtime.RawExtension{
 					Raw: providerSpecRaw,
 				},
@@ -164,6 +166,7 @@ var _ = Describe("CreateMachine - Networking", func() {
 				ObjectMeta: metav1.ObjectMeta{
 					Name: "test-machine-class",
 				},
+				Provider: "stackit",
 				ProviderSpec: runtime.RawExtension{
 					Raw: providerSpecRaw,
 				},
@@ -206,6 +209,7 @@ var _ = Describe("CreateMachine - Networking", func() {
 				ObjectMeta: metav1.ObjectMeta{
 					Name: "test-machine-class",
 				},
+				Provider: "stackit",
 				ProviderSpec: runtime.RawExtension{
 					Raw: providerSpecRaw,
 				},
@@ -255,6 +259,7 @@ var _ = Describe("CreateMachine - Networking", func() {
 				ObjectMeta: metav1.ObjectMeta{
 					Name: "test-machine-class",
 				},
+				Provider: "stackit",
 				ProviderSpec: runtime.RawExtension{
 					Raw: providerSpecRaw,
 				},
@@ -302,6 +307,7 @@ var _ = Describe("CreateMachine - Networking", func() {
 				ObjectMeta: metav1.ObjectMeta{
 					Name: "test-machine-class",
 				},
+				Provider: "stackit",
 				ProviderSpec: runtime.RawExtension{
 					Raw: providerSpecRaw,
 				},

pkg/provider/core_create_machine_storage_test.go

@@ -57,6 +57,7 @@ var _ = Describe("CreateMachine", func() {
 			ObjectMeta: metav1.ObjectMeta{
 				Name: "test-machine-class",
 			},
+			Provider: "stackit",
 			ProviderSpec: runtime.RawExtension{
 				Raw: providerSpecRaw,
 			},

pkg/provider/core_create_machine_userdata_test.go

@@ -58,6 +58,7 @@ var _ = Describe("CreateMachine", func() {
 			ObjectMeta: metav1.ObjectMeta{
 				Name: "test-machine-class",
 			},
+			Provider: "stackit",
 			ProviderSpec: runtime.RawExtension{
 				Raw: providerSpecRaw,
 			},

pkg/provider/core_list_machines_test.go

@@ -72,7 +72,9 @@ var _ = Describe("ListMachines", func() {
 
 	Context("with valid inputs", func() {
 		It("should list machines filtered by MachineClass label", func() {
-			mockClient.listServersFunc = func(_ context.Context, _, _ string) ([]*Server, error) {
+			mockClient.listServersFunc = func(_ context.Context, _, _, selector string) ([]*Server, error) {
+				Expect(selector).To(ContainSubstring("mcm.gardener.cloud/machineclass=test-machine-class"))
+
 				return []*Server{
 					{
 						ID:   "server-1",
@@ -90,14 +92,6 @@ var _ = Describe("ListMachines", func() {
 							"mcm.gardener.cloud/machine":      "machine-2",
 						},
 					},
-					{
-						ID:   "server-3",
-						Name: "machine-3",
-						Labels: map[string]string{
-							"mcm.gardener.cloud/machineclass": "other-machine-class",
-							"mcm.gardener.cloud/machine":      "machine-3",
-						},
-					},
 				}, nil
 			}
 
@@ -112,16 +106,8 @@ var _ = Describe("ListMachines", func() {
 		})
 
 		It("should return empty list when no servers match", func() {
-			mockClient.listServersFunc = func(_ context.Context, _, _ string) ([]*Server, error) {
-				return []*Server{
-					{
-						ID:   "server-1",
-						Name: "machine-1",
-						Labels: map[string]string{
-							"mcm.gardener.cloud/machineclass": "other-machine-class",
-						},
-					},
-				}, nil
+			mockClient.listServersFunc = func(_ context.Context, _, _, _ string) ([]*Server, error) {
+				return []*Server{}, nil
 			}
 
 			resp, err := provider.ListMachines(ctx, req)
@@ -132,7 +118,7 @@ var _ = Describe("ListMachines", func() {
 		})
 
 		It("should return empty list when no servers exist", func() {
-			mockClient.listServersFunc = func(_ context.Context, _, _ string) ([]*Server, error) {
+			mockClient.listServersFunc = func(_ context.Context, _, _, _ string) ([]*Server, error) {
 				return []*Server{}, nil
 			}
 
@@ -142,38 +128,11 @@ var _ = Describe("ListMachines", func() {
 			Expect(resp).NotTo(BeNil())
 			Expect(resp.MachineList).To(BeEmpty())
 		})
-
-		It("should handle servers without labels gracefully", func() {
-			mockClient.listServersFunc = func(_ context.Context, _, _ string) ([]*Server, error) {
-				return []*Server{
-					{
-						ID:     "server-1",
-						Name:   "machine-1",
-						Labels: nil, // No labels
-					},
-					{
-						ID:   "server-2",
-						Name: "machine-2",
-						Labels: map[string]string{
-							"mcm.gardener.cloud/machineclass": "test-machine-class",
-							"mcm.gardener.cloud/machine":      "machine-2",
-						},
-					},
-				}, nil
-			}
-
-			resp, err := provider.ListMachines(ctx, req)
-
-			Expect(err).NotTo(HaveOccurred())
-			Expect(resp).NotTo(BeNil())
-			Expect(resp.MachineList).To(HaveLen(1))
-			Expect(resp.MachineList).To(HaveKeyWithValue("stackit://11111111-2222-3333-4444-555555555555/server-2", "machine-2"))
-		})
 	})
 
 	Context("when STACKIT API fails", func() {
 		It("should return Internal error on API failure", func() {
-			mockClient.listServersFunc = func(_ context.Context, _, _ string) ([]*Server, error) {
+			mockClient.listServersFunc = func(_ context.Context, _, _, _ string) ([]*Server, error) {
 				return nil, fmt.Errorf("API connection failed")
 			}
 

pkg/provider/core_mocks_test.go

@@ -16,7 +16,7 @@ type mockStackitClient struct {
 	createServerFunc func(ctx context.Context, projectID, region string, req *CreateServerRequest) (*Server, error)
 	getServerFunc    func(ctx context.Context, projectID, region, serverID string) (*Server, error)
 	deleteServerFunc func(ctx context.Context, projectID, region, serverID string) error
-	listServersFunc  func(ctx context.Context, projectID, region string) ([]*Server, error)
+	listServersFunc  func(ctx context.Context, projectID, region, labelSelector string) ([]*Server, error)
 }
 
 func (m *mockStackitClient) CreateServer(ctx context.Context, projectID, region string, req *CreateServerRequest) (*Server, error) {
@@ -48,9 +48,9 @@ func (m *mockStackitClient) DeleteServer(ctx context.Context, projectID, region,
 	return nil
 }
 
-func (m *mockStackitClient) ListServers(ctx context.Context, projectID, region string) ([]*Server, error) {
+func (m *mockStackitClient) ListServers(ctx context.Context, projectID, region, labelSelector string) ([]*Server, error) {
 	if m.listServersFunc != nil {
-		return m.listServersFunc(ctx, projectID, region)
+		return m.listServersFunc(ctx, projectID, region, labelSelector)
 	}
 	return []*Server{}, nil
 }

pkg/provider/sdk_client.go

@@ -87,8 +87,23 @@ func createIAASClient(serviceAccountKey string) (*iaas.APIClient, error) {
 
 // CreateServer creates a new server via STACKIT SDK
 //
-//nolint:gocyclo//TODO:refactor
+//nolint:gocyclo,funlen//TODO:refactor
 func (c *SdkStackitClient) CreateServer(ctx context.Context, projectID, region string, req *CreateServerRequest) (*Server, error) {
+	// Check if the server got already created
+	labelSelector := fmt.Sprintf("mcm.gardener.cloud/machine=%s", req.Name)
+	servers, err := c.ListServers(ctx, projectID, region, labelSelector)
+	if err != nil {
+		return nil, fmt.Errorf("SDK ListServers with labelSelector: %v failed: %w", labelSelector, err)
+	}
+
+	if len(servers) > 1 {
+		return nil, fmt.Errorf("%v servers found for server name %v", len(servers), req.Name)
+	}
+
+	if len(servers) == 1 {
+		return servers[0], nil
+	}
+
 	// Convert our request to SDK payload
 	payload := &iaas.CreateServerPayload{
 		Name:        ptr(req.Name),
@@ -258,8 +273,14 @@ func (c *SdkStackitClient) DeleteServer(ctx context.Context, projectID, region,
 }
 
 // ListServers lists all servers in a project via STACKIT SDK
-func (c *SdkStackitClient) ListServers(ctx context.Context, projectID, region string) ([]*Server, error) {
-	sdkResponse, err := c.iaasClient.ListServers(ctx, projectID, region).Execute()
+func (c *SdkStackitClient) ListServers(ctx context.Context, projectID, region, labelSelector string) ([]*Server, error) {
+	serverRequest := c.iaasClient.ListServers(ctx, projectID, region)
+
+	if labelSelector != "" {
+		serverRequest = serverRequest.LabelSelector(labelSelector)
+	}
+
+	sdkResponse, err := serverRequest.Execute()
 	if err != nil {
 		return nil, fmt.Errorf("SDK ListServers failed: %w", err)
 	}

pkg/provider/stackit_client.go

@@ -26,7 +26,7 @@ type StackitClient interface {
 	// DeleteServer deletes a server by ID from STACKIT
 	DeleteServer(ctx context.Context, projectID, region, serverID string) error
 	// ListServers lists all servers in a project
-	ListServers(ctx context.Context, projectID, region string) ([]*Server, error)
+	ListServers(ctx context.Context, projectID, region, labelSelector string) ([]*Server, error)
 }
 
 // CreateServerRequest represents the request to create a server