Add type-aware backup job forms

internal/platform/workloads.go

@@ -16,6 +16,12 @@ import (
 
 type WorkloadManager struct{ RuntimeDir string }
 
+type Workload struct {
+	ID     string `json:"id"`
+	Name   string `json:"name"`
+	Status string `json:"status"`
+}
+
 type Prepared struct {
 	Sources     []string
 	Stopped     []model.Source
@@ -23,6 +29,49 @@ type Prepared struct {
 	Kind        model.JobType
 }
 
+func (w *WorkloadManager) Discover(ctx context.Context, kind model.JobType) ([]Workload, error) {
+	switch kind {
+	case model.JobDocker:
+		output, err := exec.CommandContext(ctx, "docker", "ps", "-a", "--format", "{{json .}}").Output()
+		if err != nil {
+			return nil, fmt.Errorf("environment: list Docker containers: %w", err)
+		}
+		var result []Workload
+		for _, line := range strings.Split(strings.TrimSpace(string(output)), "\n") {
+			if strings.TrimSpace(line) == "" {
+				continue
+			}
+			var item struct {
+				ID     string `json:"ID"`
+				Names  string `json:"Names"`
+				Status string `json:"Status"`
+			}
+			if err := json.Unmarshal([]byte(line), &item); err != nil {
+				return nil, fmt.Errorf("environment: decode Docker container list: %w", err)
+			}
+			result = append(result, Workload{ID: item.Names, Name: item.Names, Status: item.Status})
+		}
+		return result, nil
+	case model.JobVM:
+		output, err := exec.CommandContext(ctx, "virsh", "list", "--all", "--name").Output()
+		if err != nil {
+			return nil, fmt.Errorf("environment: list virtual machines: %w", err)
+		}
+		var result []Workload
+		for _, name := range strings.Split(strings.TrimSpace(string(output)), "\n") {
+			name = strings.TrimSpace(name)
+			if name == "" {
+				continue
+			}
+			state, _ := exec.CommandContext(ctx, "virsh", "domstate", name).Output()
+			result = append(result, Workload{ID: name, Name: name, Status: strings.TrimSpace(string(state))})
+		}
+		return result, nil
+	default:
+		return nil, fmt.Errorf("validation: unsupported workload type %q", kind)
+	}
+}
+
 func (w *WorkloadManager) Prepare(ctx context.Context, job model.Job) (Prepared, error) {
 	prepared := Prepared{Kind: job.Type}
 	for _, source := range job.Sources {