Handle inactive VM and Docker services

internal/platform/workloads.go

@@ -22,6 +22,12 @@ type Workload struct {
 	Status string `json:"status"`
 }
 
+type WorkloadDiscovery struct {
+	Available bool       `json:"available"`
+	Message   string     `json:"message,omitempty"`
+	Items     []Workload `json:"items"`
+}
+
 type Prepared struct {
 	Sources     []string
 	Stopped     []model.Source
@@ -29,12 +35,15 @@ type Prepared struct {
 	Kind        model.JobType
 }
 
-func (w *WorkloadManager) Discover(ctx context.Context, kind model.JobType) ([]Workload, error) {
+func (w *WorkloadManager) Discover(ctx context.Context, kind model.JobType) (WorkloadDiscovery, error) {
 	switch kind {
 	case model.JobDocker:
+		if _, err := os.Stat("/var/run/docker.sock"); err != nil {
+			return WorkloadDiscovery{Available: false, Message: "Docker is not enabled or is not running on this Unraid server.", Items: []Workload{}}, nil
+		}
 		output, err := exec.CommandContext(ctx, "docker", "ps", "-a", "--format", "{{json .}}").Output()
 		if err != nil {
-			return nil, fmt.Errorf("environment: list Docker containers: %w", err)
+			return WorkloadDiscovery{}, fmt.Errorf("environment: list Docker containers: %w", err)
 		}
 		var result []Workload
 		for _, line := range strings.Split(strings.TrimSpace(string(output)), "\n") {
@@ -47,15 +56,22 @@ func (w *WorkloadManager) Discover(ctx context.Context, kind model.JobType) ([]W
 				Status string `json:"Status"`
 			}
 			if err := json.Unmarshal([]byte(line), &item); err != nil {
-				return nil, fmt.Errorf("environment: decode Docker container list: %w", err)
+				return WorkloadDiscovery{}, 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
+		message := ""
+		if len(result) == 0 {
+			message = "Docker is active, but no containers are configured."
+		}
+		return WorkloadDiscovery{Available: true, Message: message, Items: result}, nil
 	case model.JobVM:
+		if !unraidServiceEnabled("/boot/config/domain.cfg") {
+			return WorkloadDiscovery{Available: false, Message: "The Unraid VM Manager is not enabled. Enable VMs under Settings > VM Manager to select virtual machines.", Items: []Workload{}}, nil
+		}
 		output, err := exec.CommandContext(ctx, "virsh", "list", "--all", "--name").Output()
 		if err != nil {
-			return nil, fmt.Errorf("environment: list virtual machines: %w", err)
+			return WorkloadDiscovery{}, fmt.Errorf("environment: VM Manager is enabled but virtual machines could not be listed: %w", err)
 		}
 		var result []Workload
 		for _, name := range strings.Split(strings.TrimSpace(string(output)), "\n") {
@@ -66,12 +82,30 @@ func (w *WorkloadManager) Discover(ctx context.Context, kind model.JobType) ([]W
 			state, _ := exec.CommandContext(ctx, "virsh", "domstate", name).Output()
 			result = append(result, Workload{ID: name, Name: name, Status: strings.TrimSpace(string(state))})
 		}
-		return result, nil
+		message := ""
+		if len(result) == 0 {
+			message = "The VM Manager is active, but no virtual machines are configured."
+		}
+		return WorkloadDiscovery{Available: true, Message: message, Items: result}, nil
 	default:
-		return nil, fmt.Errorf("validation: unsupported workload type %q", kind)
+		return WorkloadDiscovery{}, fmt.Errorf("validation: unsupported workload type %q", kind)
 	}
 }
 
+func unraidServiceEnabled(path string) bool {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return false
+	}
+	for _, line := range strings.Split(string(data), "\n") {
+		parts := strings.SplitN(strings.TrimSpace(line), "=", 2)
+		if len(parts) == 2 && parts[0] == "SERVICE" {
+			return strings.Trim(strings.TrimSpace(parts[1]), "\"'") == "enable"
+		}
+	}
+	return false
+}
+
 func (w *WorkloadManager) Prepare(ctx context.Context, job model.Job) (Prepared, error) {
 	prepared := Prepared{Kind: job.Type}
 	for _, source := range job.Sources {