refactor(client): speed up service list call (N -> 1 broadcast RPC)

pkg/client/service.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"maps"
 	"slices"
 	"sync"
 
@@ -320,40 +321,18 @@ func (cli *Client) StartService(ctx context.Context, id string) error {
 
 // ListServices returns a list of all services and their containers.
 func (cli *Client) ListServices(ctx context.Context) ([]api.Service, error) {
-	machines, err := cli.ListMachines(ctx, nil)
-	if err != nil {
-		return nil, fmt.Errorf("list machines: %w", err)
-	}
-
-	// Broadcast the container list request to all available machines.
-	md := metadata.New(nil)
-	for _, m := range machines {
-		if m.State == pb.MachineMember_UP || m.State == pb.MachineMember_SUSPECT {
-			md.Append("machines", m.Machine.Id)
-		} else {
-			tui.PrintWarning(fmt.Sprintf("failed to list service containers on machine '%s' (state is %s). "+
-				"The results may be incomplete.", m.Machine.Name, m.State.String()))
-		}
-	}
-	listCtx := metadata.NewOutgoingContext(ctx, md)
-
-	// List all containers including stopped ones.
+	// Broadcast the container list request to all machines in the cluster.
+	listCtx := ProxyMachinesContext(ctx, nil)
+	// List all containers including stopped ones and deployment hooks.
 	opts := container.ListOptions{All: true}
 	machineContainers, err := cli.Docker.ListServiceContainers(listCtx, "", opts)
 	if err != nil {
 		return nil, fmt.Errorf("list containers: %w", err)
 	}
 
-	// TODO: optimise by extracting services from the list of all containers instead of inspecting each service.
-	//  Most of the code can be reused in both InspectService and ListServices.
+	// Group containers by service ID using the broadcast results.
 	servicesByID := make(map[string]api.Service)
 	for _, mc := range machineContainers {
-		// NOTE: Metadata should never be nil in practice. This is legacy fallback that will be removed.
-		if mc.Metadata == nil {
-			tui.PrintWarning("metadata is missing in response from unknown server")
-			continue
-		}
-
 		if mc.Metadata.Error != "" {
 			// TODO: return failed machines in the response.
 			tui.PrintWarning(fmt.Sprintf("failed to list containers on machine '%s': %s",
@@ -362,25 +341,30 @@ func (cli *Client) ListServices(ctx context.Context) ([]api.Service, error) {
 		}
 
 		for _, ctr := range append(mc.Containers, mc.HookContainers...) {
-			if _, ok := servicesByID[ctr.ServiceID()]; ok {
-				continue
-			}
-
-			svc, err := cli.InspectService(ctx, ctr.ServiceID())
-			if err != nil {
-				if errors.Is(err, api.ErrNotFound) {
-					continue
+			serviceID := ctr.ServiceID()
+			svc, ok := servicesByID[serviceID]
+			if !ok {
+				svc = api.Service{
+					ID:   serviceID,
+					Name: ctr.ServiceName(),
+					Mode: ctr.ServiceMode(),
 				}
-				return nil, fmt.Errorf("inspect service: %w", err)
 			}
 
-			servicesByID[ctr.ServiceID()] = svc
+			machineContainer := api.MachineServiceContainer{
+				MachineID:   mc.Metadata.MachineId,
+				MachineName: mc.Metadata.MachineName,
+				Container:   ctr,
+			}
+			if ctr.IsHook() {
+				svc.HookContainers = append(svc.HookContainers, machineContainer)
+			} else {
+				svc.Containers = append(svc.Containers, machineContainer)
+			}
+
+			servicesByID[serviceID] = svc
 		}
 	}
 
-	services := make([]api.Service, 0, len(servicesByID))
-	for _, svc := range servicesByID {
-		services = append(services, svc)
-	}
-	return services, nil
+	return slices.Collect(maps.Values(servicesByID)), nil
 }