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]()