chore: refactor schedulers to work with cluster state snapshot, VolumeScheduler updates state with scheduled volumes

pkg/client/deploy/scheduler/state.go

@@ -0,0 +1,59 @@
+package scheduler
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/docker/docker/api/types/volume"
+	"github.com/psviderski/uncloud/internal/machine/api/pb"
+	"github.com/psviderski/uncloud/pkg/api"
+)
+
+// ClusterState represents the current and planned state of machines and their resources in the cluster.
+type ClusterState struct {
+	Machines []*Machine
+}
+
+type Machine struct {
+	Info             *pb.MachineInfo
+	Volumes          []volume.Volume
+	ScheduledVolumes []api.VolumeSpec
+}
+
+type Client interface {
+	api.MachineClient
+	api.VolumeClient
+}
+
+// InspectClusterState creates a new cluster state by inspecting the machines using the cluster client.
+func InspectClusterState(ctx context.Context, cli Client) (*ClusterState, error) {
+	// TODO: refactor to get all the details in one broadcast call to machine API,
+	//  e.g. InspectMachine with include options.
+	machineMembers, err := cli.ListMachines(ctx, &api.MachineFilter{Available: true})
+	if err != nil {
+		return nil, fmt.Errorf("list machines: %w", err)
+	}
+	volumes, err := cli.ListVolumes(ctx, nil)
+	if err != nil {
+		return nil, fmt.Errorf("list volumes: %w", err)
+	}
+
+	var machines []*Machine
+	for _, m := range machineMembers {
+		machine := &Machine{
+			Info: m.Machine,
+		}
+
+		for _, v := range volumes {
+			if v.MachineID == m.Machine.Id {
+				machine.Volumes = append(machine.Volumes, v.Volume)
+			}
+		}
+
+		machines = append(machines, machine)
+	}
+
+	return &ClusterState{
+		Machines: machines,
+	}, nil
+}