feat(logs): update 'uc logs' command to support filtering by service/container

pkg/api/logs.go

@@ -46,12 +46,16 @@ func LogStreamTypeToProto(s LogStreamType) pb.LogEntry_StreamType {
 	}
 }
 
-// ServiceLogsOptions specifies parameters for ServiceLogs.
+// ServiceLogsOptions specifies parameters for ServiceLogs and MachineLogs.
 type ServiceLogsOptions struct {
 	Follow bool
 	Tail   int
 	Since  string
 	Until  string
+	// Containers filters logs to only include the specified service containers (names, full IDs,
+	// or unique ID prefixes). If empty, logs from all containers in the service are included.
+	// Ignored by MachineLogs.
+	Containers []string
 	// Machines filters logs to only include containers running on the specified machines (names or IDs).
 	// If empty, logs from all machines are included.
 	Machines []string

pkg/api/service.go

@@ -519,6 +519,29 @@ type MachineServiceContainer struct {
 	Container ServiceContainer
 }
 
+// FindContainer returns the service container by exact name, ID, or unique ID prefix.
+// Returns ErrNotFound if no container matches, or an error if an ID prefix matches more than one container.
+func (s *Service) FindContainer(nameOrID string) (MachineServiceContainer, error) {
+	var prefixMatches []MachineServiceContainer
+	for _, c := range append(s.Containers, s.HookContainers...) {
+		if c.Container.ID == nameOrID || c.Container.Name == nameOrID {
+			return c, nil
+		}
+		if strings.HasPrefix(c.Container.ID, nameOrID) {
+			prefixMatches = append(prefixMatches, c)
+		}
+	}
+
+	if len(prefixMatches) == 1 {
+		return prefixMatches[0], nil
+	}
+	if len(prefixMatches) > 1 {
+		return MachineServiceContainer{}, fmt.Errorf("multiple containers found with ID prefix '%s'", nameOrID)
+	}
+
+	return MachineServiceContainer{}, ErrNotFound
+}
+
 // MachineIDs returns a list of unique machine IDs where the service containers are running.
 func (s *Service) MachineIDs() []string {
 	ids := mapset.NewSet[string]()

pkg/client/container.go

@@ -256,26 +256,7 @@ func (cli *Client) InspectContainer(
 		return api.MachineServiceContainer{}, fmt.Errorf("inspect service: %w", err)
 	}
 
-	prefixMatchCandidates := []api.MachineServiceContainer{}
-	for _, c := range append(svc.Containers, svc.HookContainers...) {
-		if c.Container.ID == containerNameOrID ||
-			c.Container.Name == containerNameOrID {
-			return c, nil
-		}
-
-		if strings.HasPrefix(c.Container.ID, containerNameOrID) {
-			prefixMatchCandidates = append(prefixMatchCandidates, c)
-		}
-	}
-
-	if len(prefixMatchCandidates) == 1 {
-		return prefixMatchCandidates[0], nil
-	} else if len(prefixMatchCandidates) > 1 {
-		return api.MachineServiceContainer{}, fmt.Errorf(
-			"multiple containers found with ID prefix '%s'", containerNameOrID)
-	}
-
-	return api.MachineServiceContainer{}, api.ErrNotFound
+	return svc.FindContainer(containerNameOrID)
 }
 
 // StartContainer starts the specified container within the service.

pkg/client/logs.go

@@ -5,6 +5,8 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"maps"
+	"slices"
 
 	"github.com/docker/docker/pkg/stringid"
 	"github.com/psviderski/uncloud/internal/machine/api/pb"
@@ -24,11 +26,25 @@ func (cli *Client) ServiceLogs(
 		return svc, nil, fmt.Errorf("inspect service: %w", err)
 	}
 
-	allContainers := append(svc.Containers, svc.HookContainers...)
-	if len(allContainers) == 0 {
+	containers := append(svc.Containers, svc.HookContainers...)
+	if len(containers) == 0 {
 		return svc, nil, fmt.Errorf("no containers found for service: %s", serviceNameOrID)
 	}
 
+	if len(opts.Containers) > 0 {
+		selected := make(map[string]api.MachineServiceContainer, len(opts.Containers))
+		for _, nameOrID := range opts.Containers {
+			ctr, err := svc.FindContainer(nameOrID)
+			if err != nil {
+				return svc, nil, fmt.Errorf("find container '%s' in service '%s': %w",
+					nameOrID, serviceNameOrID, err)
+			}
+			selected[ctr.Container.ID] = ctr
+		}
+
+		containers = slices.Collect(maps.Values(selected))
+	}
+
 	machines, err := cli.ListMachines(ctx, &api.MachineFilter{
 		NamesOrIDs: opts.Machines,
 	})
@@ -36,8 +52,8 @@ func (cli *Client) ServiceLogs(
 		return svc, nil, fmt.Errorf("list machines: %w", err)
 	}
 
-	ctrStreams := make([]<-chan api.ServiceLogEntry, 0, len(allContainers))
-	for _, ctr := range allContainers {
+	ctrStreams := make([]<-chan api.ServiceLogEntry, 0, len(containers))
+	for _, ctr := range containers {
 		// Skip containers not running on the specified machines.
 		m := machines.FindByNameOrID(ctr.MachineID)
 		if len(opts.Machines) > 0 && m == nil {