[node operator] Add GCP client

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

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

@@ -0,0 +1,134 @@
+package client
+
+import (
+	"context"
+	"fmt"
+
+	computepb "google.golang.org/genproto/googleapis/cloud/compute/v1"
+	"google.golang.org/protobuf/proto"
+)
+
+// GetNodeImage returns the image name of the node.
+func (c *Client) GetNodeImage(ctx context.Context, providerID string) (string, error) {
+	project, zone, instanceName, err := splitProviderID(providerID)
+	if err != nil {
+		return "", err
+	}
+	instance, err := c.instanceAPI.Get(ctx, &computepb.GetInstanceRequest{
+		Instance: instanceName,
+		Project:  project,
+		Zone:     zone,
+	})
+	if err != nil {
+		return "", err
+	}
+	// first disk is always the boot disk
+	if len(instance.Disks) < 1 {
+		return "", fmt.Errorf("instance %v has no disks", instanceName)
+	}
+	if instance.Disks[0] == nil || instance.Disks[0].Source == nil {
+		return "", fmt.Errorf("instance %q has invalid disk", instanceName)
+	}
+	diskReq, err := diskSourceToDiskReq(*instance.Disks[0].Source)
+	if err != nil {
+		return "", err
+	}
+	disk, err := c.diskAPI.Get(ctx, diskReq)
+	if err != nil {
+		return "", err
+	}
+	if disk.SourceImage == nil {
+		return "", fmt.Errorf("disk %q has no source image", diskReq.Disk)
+	}
+	return uriNormalize(*disk.SourceImage), nil
+}
+
+// GetScalingGroupID returns the scaling group ID of the node.
+func (c *Client) GetScalingGroupID(ctx context.Context, providerID string) (string, error) {
+	project, zone, instanceName, err := splitProviderID(providerID)
+	if err != nil {
+		return "", err
+	}
+	instance, err := c.instanceAPI.Get(ctx, &computepb.GetInstanceRequest{
+		Instance: instanceName,
+		Project:  project,
+		Zone:     zone,
+	})
+	if err != nil {
+		return "", fmt.Errorf("getting instance %q: %w", instanceName, err)
+	}
+	scalingGroupID := getMetadataByKey(instance.Metadata, "created-by")
+	if scalingGroupID == "" {
+		return "", fmt.Errorf("instance %q has no created-by metadata", instanceName)
+	}
+	return scalingGroupID, nil
+}
+
+// CreateNode creates a node in the specified scaling group.
+func (c *Client) CreateNode(ctx context.Context, scalingGroupID string) (nodeName, providerID string, err error) {
+	project, zone, instanceGroupName, err := splitInstanceGroupID(scalingGroupID)
+	if err != nil {
+		return "", "", err
+	}
+	instanceGroupManager, err := c.instanceGroupManagersAPI.Get(ctx, &computepb.GetInstanceGroupManagerRequest{
+		InstanceGroupManager: instanceGroupName,
+		Project:              project,
+		Zone:                 zone,
+	})
+	if err != nil {
+		return "", "", err
+	}
+	if instanceGroupManager.BaseInstanceName == nil {
+		return "", "", fmt.Errorf("instance group manager %q has no base instance name", instanceGroupName)
+	}
+	instanceName, err := generateInstanceName(*instanceGroupManager.BaseInstanceName, c.prng)
+	if err != nil {
+		return "", "", err
+	}
+	op, err := c.instanceGroupManagersAPI.CreateInstances(ctx, &computepb.CreateInstancesInstanceGroupManagerRequest{
+		InstanceGroupManager: instanceGroupName,
+		Project:              project,
+		Zone:                 zone,
+		InstanceGroupManagersCreateInstancesRequestResource: &computepb.InstanceGroupManagersCreateInstancesRequest{
+			Instances: []*computepb.PerInstanceConfig{
+				{Name: proto.String(instanceName)},
+			},
+		},
+	})
+	if err != nil {
+		return "", "", err
+	}
+	if err := op.Wait(ctx); err != nil {
+		return "", "", err
+	}
+	return instanceName, joinProviderID(project, zone, instanceName), nil
+}
+
+// DeleteNode deletes a node specified by its provider ID.
+func (c *Client) DeleteNode(ctx context.Context, providerID string) error {
+	_, zone, instanceName, err := splitProviderID(providerID)
+	if err != nil {
+		return err
+	}
+	scalingGroupID, err := c.GetScalingGroupID(ctx, providerID)
+	if err != nil {
+		return err
+	}
+	instanceGroupProject, instanceGroupZone, instanceGroupName, err := splitInstanceGroupID(scalingGroupID)
+	if err != nil {
+		return err
+	}
+	instanceID := joinInstanceID(zone, instanceName)
+	op, err := c.instanceGroupManagersAPI.DeleteInstances(ctx, &computepb.DeleteInstancesInstanceGroupManagerRequest{
+		InstanceGroupManager: instanceGroupName,
+		Project:              instanceGroupProject,
+		Zone:                 instanceGroupZone,
+		InstanceGroupManagersDeleteInstancesRequestResource: &computepb.InstanceGroupManagersDeleteInstancesRequest{
+			Instances: []string{instanceID},
+		},
+	})
+	if err != nil {
+		return fmt.Errorf("deleting instance %q from instance group manager %q: %w", instanceID, scalingGroupID, err)
+	}
+	return op.Wait(ctx)
+}