[node operator] Add Azure client

Signed-off-by: Malte Poll <mp@edgeless.systems>

operators/constellation-node-operator/internal/azure/client/nodeimage.go

@@ -0,0 +1,156 @@
+package client
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/compute/armcompute/v2"
+)
+
+// GetNodeImage returns the image name of the node.
+func (c *Client) GetNodeImage(ctx context.Context, providerID string) (string, error) {
+	_, resourceGroup, scaleSet, instanceID, err := scaleSetInformationFromProviderID(providerID)
+	if err != nil {
+		return "", err
+	}
+	resp, err := c.virtualMachineScaleSetVMsAPI.Get(ctx, resourceGroup, scaleSet, instanceID, nil)
+	if err != nil {
+		return "", err
+	}
+	if resp.Properties == nil ||
+		resp.Properties.StorageProfile == nil ||
+		resp.Properties.StorageProfile.ImageReference == nil ||
+		resp.Properties.StorageProfile.ImageReference.ID == nil {
+		return "", fmt.Errorf("node %q does not have valid image reference", providerID)
+	}
+	return *resp.Properties.StorageProfile.ImageReference.ID, nil
+}
+
+// GetScalingGroupID returns the scaling group ID of the node.
+func (c *Client) GetScalingGroupID(ctx context.Context, providerID string) (string, error) {
+	subscriptionID, resourceGroup, scaleSet, _, err := scaleSetInformationFromProviderID(providerID)
+	if err != nil {
+		return "", err
+	}
+	return joinVMSSID(subscriptionID, resourceGroup, scaleSet), nil
+}
+
+// CreateNode creates a node in the specified scaling group.
+func (c *Client) CreateNode(ctx context.Context, scalingGroupID string) (nodeName, providerID string, err error) {
+	_, resourceGroup, scaleSet, err := splitVMSSID(scalingGroupID)
+	if err != nil {
+		return "", "", err
+	}
+
+	// get list of instance IDs before scaling,
+	var oldVMIDs []string
+	pager := c.virtualMachineScaleSetVMsAPI.NewListPager(resourceGroup, scaleSet, nil)
+	for pager.More() {
+		page, err := pager.NextPage(ctx)
+		if err != nil {
+			return "", "", err
+		}
+		for _, vm := range page.Value {
+			if vm == nil || vm.ID == nil {
+				continue
+			}
+			oldVMIDs = append(oldVMIDs, *vm.ID)
+		}
+	}
+
+	// increase the number of instances by one
+	resp, err := c.scaleSetsAPI.Get(ctx, resourceGroup, scaleSet, nil)
+	if err != nil {
+		return "", "", err
+	}
+	if resp.SKU == nil || resp.SKU.Capacity == nil {
+		return "", "", fmt.Errorf("scale set %q does not have valid capacity", scaleSet)
+	}
+	wantedCapacity := *resp.SKU.Capacity + 1
+	_, err = c.scaleSetsAPI.BeginUpdate(ctx, resourceGroup, scaleSet, armcompute.VirtualMachineScaleSetUpdate{
+		SKU: &armcompute.SKU{
+			Capacity: &wantedCapacity,
+		},
+	}, nil)
+	if err != nil {
+		return "", "", err
+	}
+
+	poller := c.capacityPollerGenerator(resourceGroup, scaleSet, wantedCapacity)
+	if _, err := poller.PollUntilDone(ctx, c.pollerOptions); err != nil {
+		return "", "", err
+	}
+
+	// get the list of instances again
+	// and find the new instance id by comparing the old and new lists
+	pager = c.virtualMachineScaleSetVMsAPI.NewListPager(resourceGroup, scaleSet, nil)
+	for pager.More() {
+		page, err := pager.NextPage(ctx)
+		if err != nil {
+			return "", "", err
+		}
+		for _, vm := range page.Value {
+			// check if the instance already existed in the old list
+			if !hasKnownVMID(vm, oldVMIDs) {
+				return strings.ToLower(*vm.Properties.OSProfile.ComputerName), "azure://" + *vm.ID, nil
+			}
+		}
+	}
+	return "", "", fmt.Errorf("failed to find new node after scaling up")
+}
+
+// DeleteNode deletes a node specified by its provider ID.
+func (c *Client) DeleteNode(ctx context.Context, providerID string) error {
+	_, resourceGroup, scaleSet, instanceID, err := scaleSetInformationFromProviderID(providerID)
+	if err != nil {
+		return err
+	}
+	ids := armcompute.VirtualMachineScaleSetVMInstanceRequiredIDs{InstanceIDs: []*string{&instanceID}}
+	_, err = c.scaleSetsAPI.BeginDeleteInstances(ctx, resourceGroup, scaleSet, ids, nil)
+	return err
+}
+
+// capacityPollingHandler polls a scale set
+// until its capacity reaches the desired value.
+type capacityPollingHandler struct {
+	done           bool
+	wantedCapacity int64
+	resourceGroup  string
+	scaleSet       string
+	scaleSetsAPI
+}
+
+func (h *capacityPollingHandler) Done() bool {
+	return h.done
+}
+
+func (h *capacityPollingHandler) Poll(ctx context.Context) error {
+	resp, err := h.scaleSetsAPI.Get(ctx, h.resourceGroup, h.scaleSet, nil)
+	if err != nil {
+		return err
+	}
+	if resp.SKU == nil || resp.SKU.Capacity == nil {
+		return fmt.Errorf("scale set %q does not have valid capacity", h.scaleSet)
+	}
+	h.done = *resp.SKU.Capacity == h.wantedCapacity
+	return nil
+}
+
+func (h *capacityPollingHandler) Result(ctx context.Context, out *int64) error {
+	if !h.done {
+		return fmt.Errorf("failed to scale up")
+	}
+	*out = h.wantedCapacity
+	return nil
+}
+
+// hasKnownVMID returns true if the vmID is found in the vm ID list.
+func hasKnownVMID(vm *armcompute.VirtualMachineScaleSetVM, vmIDs []string) bool {
+	for _, id := range vmIDs {
+		if vm != nil && vm.ID != nil && *vm.ID == id {
+			return true
+		}
+	}
+	return false
+}