package libpod import ( "github.com/docker/docker/pkg/truncindex" "github.com/pkg/errors" "github.com/projectatomic/libpod/pkg/registrar" ) // An InMemoryState is a purely in-memory state store type InMemoryState struct { pods map[string]*Pod containers map[string]*Container podNameIndex *registrar.Registrar podIDIndex *truncindex.TruncIndex ctrNameIndex *registrar.Registrar ctrIDIndex *truncindex.TruncIndex } // NewInMemoryState initializes a new, empty in-memory state func NewInMemoryState() (State, error) { state := new(InMemoryState) state.pods = make(map[string]*Pod) state.containers = make(map[string]*Container) state.podNameIndex = registrar.NewRegistrar() state.ctrNameIndex = registrar.NewRegistrar() state.podIDIndex = truncindex.NewTruncIndex([]string{}) state.ctrIDIndex = truncindex.NewTruncIndex([]string{}) return state, nil } // Close the state before shutdown // This is a no-op as we have no backing disk func (s *InMemoryState) Close() error { return nil } // Refresh clears container and pod stats after a reboot // In-memory state won't survive a reboot so this is a no-op func (s *InMemoryState) Refresh() error { return nil } // Container retrieves a container from its full ID func (s *InMemoryState) Container(id string) (*Container, error) { if id == "" { return nil, ErrEmptyID } ctr, ok := s.containers[id] if !ok { return nil, errors.Wrapf(ErrNoSuchCtr, "no container with ID %s found", id) } return ctr, nil } // LookupContainer retrieves a container by full ID, unique partial ID, or name func (s *InMemoryState) LookupContainer(idOrName string) (*Container, error) { if idOrName == "" { return nil, ErrEmptyID } fullID, err := s.ctrNameIndex.Get(idOrName) if err != nil { if err == registrar.ErrNameNotReserved { // What was passed is not a name, assume it's an ID fullID, err = s.ctrIDIndex.Get(idOrName) if err != nil { if err == truncindex.ErrNotExist { return nil, errors.Wrapf(ErrNoSuchCtr, "no container found with name or ID %s", idOrName) } return nil, errors.Wrapf(err, "error performing truncindex lookup for ID %s", idOrName) } } else { return nil, errors.Wrapf(err, "error performing registry lookup for ID %s", idOrName) } } ctr, ok := s.containers[fullID] if !ok { // This should never happen return nil, errors.Wrapf(ErrInternal, "mismatch in container ID registry and containers map for ID %s", fullID) } return ctr, nil } // HasContainer checks if a container with the given ID is present in the state func (s *InMemoryState) HasContainer(id string) (bool, error) { if id == "" { return false, ErrEmptyID } _, ok := s.containers[id] return ok, nil } // AddContainer adds a container to the state // If the container belongs to a pod, the pod must already be present when the // container is added, and the container must be present in the pod func (s *InMemoryState) AddContainer(ctr *Container) error { if !ctr.valid { return errors.Wrapf(ErrCtrRemoved, "container with ID %s is not valid", ctr.ID()) } _, ok := s.containers[ctr.ID()] if ok { return errors.Wrapf(ErrCtrExists, "container with ID %s already exists in state", ctr.ID()) } if ctr.pod != nil { if _, ok := s.pods[ctr.pod.ID()]; !ok { return errors.Wrapf(ErrNoSuchPod, "pod %s does not exist, cannot add container %s", ctr.pod.ID(), ctr.ID()) } hasCtr, err := ctr.pod.HasContainer(ctr.ID()) if err != nil { return errors.Wrapf(err, "error checking if container %s is present in pod %s", ctr.ID(), ctr.pod.ID()) } else if !hasCtr { return errors.Wrapf(ErrNoSuchCtr, "container %s is not present in pod %s", ctr.ID(), ctr.pod.ID()) } } if err := s.ctrNameIndex.Reserve(ctr.Name(), ctr.ID()); err != nil { return errors.Wrapf(err, "error registering container name %s", ctr.Name()) } if err := s.ctrIDIndex.Add(ctr.ID()); err != nil { s.ctrNameIndex.Release(ctr.Name()) return errors.Wrapf(err, "error registering container ID %s", ctr.ID()) } s.containers[ctr.ID()] = ctr return nil } // RemoveContainer removes a container from the state // The container will only be removed from the state, not from the pod the container belongs to func (s *InMemoryState) RemoveContainer(ctr *Container) error { // Almost no validity checks are performed, to ensure we can kick // misbehaving containers out of the state if _, ok := s.containers[ctr.ID()]; !ok { return errors.Wrapf(ErrNoSuchCtr, "no container exists in state with ID %s", ctr.ID()) } if err := s.ctrIDIndex.Delete(ctr.ID()); err != nil { return errors.Wrapf(err, "error removing container ID from index") } delete(s.containers, ctr.ID()) s.ctrNameIndex.Release(ctr.Name()) return nil } // UpdateContainer updates a container's state // As all state is in-memory, no update will be required // As such this is a no-op func (s *InMemoryState) UpdateContainer(ctr *Container) error { return nil } // SaveContainer saves a container's state // As all state is in-memory, any changes are always reflected as soon as they // are made // As such this is a no-op func (s *InMemoryState) SaveContainer(ctr *Container) error { return nil } // AllContainers retrieves all containers from the state func (s *InMemoryState) AllContainers() ([]*Container, error) { ctrs := make([]*Container, 0, len(s.containers)) for _, ctr := range s.containers { ctrs = append(ctrs, ctr) } return ctrs, nil } // Pod retrieves a pod from the state from its full ID func (s *InMemoryState) Pod(id string) (*Pod, error) { if id == "" { return nil, ErrEmptyID } pod, ok := s.pods[id] if !ok { return nil, errors.Wrapf(ErrNoSuchPod, "no pod with id %s found", id) } return pod, nil } // LookupPod retrieves a pod from the state from a full or unique partial ID or // a full name func (s *InMemoryState) LookupPod(idOrName string) (*Pod, error) { if idOrName == "" { return nil, ErrEmptyID } fullID, err := s.podNameIndex.Get(idOrName) if err != nil { if err == registrar.ErrNameNotReserved { // What was passed is not a name, assume it's an ID fullID, err = s.podIDIndex.Get(idOrName) if err != nil { if err == truncindex.ErrNotExist { return nil, errors.Wrapf(ErrNoSuchPod, "no pod found with name or ID %s", idOrName) } return nil, errors.Wrapf(err, "error performing truncindex lookup for ID %s", idOrName) } } else { return nil, errors.Wrapf(err, "error performing registry lookup for ID %s", idOrName) } } pod, ok := s.pods[fullID] if !ok { // This should never happen return nil, errors.Wrapf(ErrInternal, "mismatch in pod ID registry and pod map for ID %s", fullID) } return pod, nil } // HasPod checks if a pod with the given ID is present in the state func (s *InMemoryState) HasPod(id string) (bool, error) { if id == "" { return false, ErrEmptyID } _, ok := s.pods[id] return ok, nil } // AddPod adds a given pod to the state // Only empty pods can be added to the state func (s *InMemoryState) AddPod(pod *Pod) error { if !pod.valid { return errors.Wrapf(ErrPodRemoved, "pod %s is not valid and cannot be added", pod.ID()) } if _, ok := s.pods[pod.ID()]; ok { return errors.Wrapf(ErrPodExists, "pod with ID %s already exists in state", pod.ID()) } if len(pod.containers) != 0 { return errors.Wrapf(ErrInternal, "only empty pods can be added to the state") } if err := s.podNameIndex.Reserve(pod.Name(), pod.ID()); err != nil { return errors.Wrapf(err, "error registering pod name %s", pod.Name()) } if err := s.podIDIndex.Add(pod.ID()); err != nil { s.podNameIndex.Release(pod.Name()) return errors.Wrapf(err, "error registering pod ID %s", pod.ID()) } s.pods[pod.ID()] = pod return nil } // RemovePod removes a given pod from the state // Containers within the pod will not be removed or changed func (s *InMemoryState) RemovePod(pod *Pod) error { // Don't make many validity checks to ensure we can kick badly formed // pods out of the state if _, ok := s.pods[pod.ID()]; !ok { return errors.Wrapf(ErrNoSuchPod, "no pod exists in state with ID %s", pod.ID()) } if err := s.podIDIndex.Delete(pod.ID()); err != nil { return errors.Wrapf(err, "error removing pod ID %s from index", pod.ID()) } delete(s.pods, pod.ID()) s.podNameIndex.Release(pod.Name()) return nil } // AllPods retrieves all pods currently in the state func (s *InMemoryState) AllPods() ([]*Pod, error) { pods := make([]*Pod, 0, len(s.pods)) for _, pod := range s.pods { pods = append(pods, pod) } return pods, nil }