github/containerd
4
0
Fork 0
Code Issues Pull Requests Packages Projects Releases 2 Wiki Activity

events: refactor event distribution

Browse Source 
In the course of setting out to add filters and address some cleanup, it
was found that we had a few problems in the events subsystem that needed
addressing before moving forward.

The biggest change was to move to the more standard terminology of
publish and subscribe. We make this terminology change across the Go
interface and the GRPC API, making the behavior more familier. The
previous system was very context-oriented, which is no longer required.

With this, we've removed a large amount of dead and unneeded code. Event
transactions, context storage and the concept of `Poster` is gone. This
has been replaced in most places with a `Publisher`, which matches the
actual usage throughout the codebase, removing the need for helpers.

There are still some questions around the way events are handled in the
shim. Right now, we've preserved some of the existing bugs which may
require more extensive changes to resolve correctly.

Signed-off-by: Stephen J Day <stephen.day@docker.com>
This commit is contained in:
Stephen J Day
2017-07-24 22:19:02 -07:00
parent a9ab45fb77
commit a615a6fe5d
30 changed files with 669 additions and 644 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
services/containers/service.go
View File

@@ -24,23 +24,22 @@ func init() {
plugin.MetadataPlugin,
},
Init: func(ic *plugin.InitContext) (interface{}, error) {
e := events.GetPoster(ic.Context)
m, err := ic.Get(plugin.MetadataPlugin)
if err != nil {
return nil, err
}
return NewService(m.(*bolt.DB), e), nil
return NewService(m.(*bolt.DB), ic.Events), nil
},
})
}
type Service struct {
db *bolt.DB
emitter events.Poster
db *bolt.DB
publisher events.Publisher
}
func NewService(db *bolt.DB, evts events.Poster) api.ContainersServer {
return &Service{db: db, emitter: evts}
func NewService(db *bolt.DB, publisher events.Publisher) api.ContainersServer {
return &Service{db: db, publisher: publisher}
}
func (s *Service) Register(server *grpc.Server) error {
@@ -94,7 +93,7 @@ func (s *Service) Create(ctx context.Context, req *api.CreateContainerRequest) (
}); err != nil {
return &resp, errdefs.ToGRPC(err)
}
if err := s.emit(ctx, "/containers/create", &eventsapi.ContainerCreate{
if err := s.publisher.Publish(ctx, "/containers/create", &eventsapi.ContainerCreate{
ID: resp.Container.ID,
Image: resp.Container.Image,
Runtime: &eventsapi.ContainerCreate_Runtime{
@@ -136,7 +135,7 @@ func (s *Service) Update(ctx context.Context, req *api.UpdateContainerRequest) (
return &resp, errdefs.ToGRPC(err)
}
if err := s.emit(ctx, "/containers/update", &eventsapi.ContainerUpdate{
if err := s.publisher.Publish(ctx, "/containers/update", &eventsapi.ContainerUpdate{
ID: resp.Container.ID,
Image: resp.Container.Image,
Labels: resp.Container.Labels,
@@ -155,7 +154,7 @@ func (s *Service) Delete(ctx context.Context, req *api.DeleteContainerRequest) (
return &empty.Empty{}, errdefs.ToGRPC(err)
}
if err := s.emit(ctx, "/containers/delete", &eventsapi.ContainerDelete{
if err := s.publisher.Publish(ctx, "/containers/delete", &eventsapi.ContainerDelete{
ID: req.ID,
}); err != nil {
return &empty.Empty{}, err
@@ -175,12 +174,3 @@ func (s *Service) withStoreView(ctx context.Context, fn func(ctx context.Context
func (s *Service) withStoreUpdate(ctx context.Context, fn func(ctx context.Context, store containers.Store) error) error {
return s.db.Update(s.withStore(ctx, fn))
}
func (s *Service) emit(ctx context.Context, topic string, evt interface{}) error {
emitterCtx := events.WithTopic(ctx, topic)
if err := s.emitter.Post(emitterCtx, evt); err != nil {
return err
}
return nil
}

19
services/content/service.go
View File

@@ -23,8 +23,8 @@ import (
)
type Service struct {
store content.Store
emitter events.Poster
store content.Store
publisher events.Publisher
}
var bufPool = sync.Pool{
@@ -58,8 +58,8 @@ func NewService(ic *plugin.InitContext) (interface{}, error) {
}
cs := metadata.NewContentStore(m.(*bolt.DB), c.(content.Store))
return &Service{
store: cs,
emitter: events.GetPoster(ic.Context),
store: cs,
publisher: ic.Events,
}, nil
}
@@ -149,7 +149,7 @@ func (s *Service) Delete(ctx context.Context, req *api.DeleteContentRequest) (*e
return nil, errdefs.ToGRPC(err)
}
if err := s.emit(ctx, "/content/delete", &eventsapi.ContentDelete{
if err := s.publisher.Publish(ctx, "/content/delete", &eventsapi.ContentDelete{
Digest: req.Digest,
}); err != nil {
return nil, err
@@ -459,12 +459,3 @@ func (s *Service) Abort(ctx context.Context, req *api.AbortRequest) (*empty.Empt
return &empty.Empty{}, nil
}
func (s *Service) emit(ctx context.Context, topic string, evt interface{}) error {
emitterCtx := events.WithTopic(ctx, topic)
if err := s.emitter.Post(emitterCtx, evt); err != nil {
return err
}
return nil
}

56
services/events/service.go
View File

@@ -1,14 +1,13 @@
package events
import (
"fmt"
"time"
api "github.com/containerd/containerd/api/services/events/v1"
"github.com/containerd/containerd/errdefs"
"github.com/containerd/containerd/events"
"github.com/containerd/containerd/filters"
"github.com/containerd/containerd/plugin"
"github.com/golang/protobuf/ptypes/empty"
"github.com/sirupsen/logrus"
"github.com/pkg/errors"
"golang.org/x/net/context"
"google.golang.org/grpc"
)
@@ -18,18 +17,17 @@ func init() {
Type: plugin.GRPCPlugin,
ID: "events",
Init: func(ic *plugin.InitContext) (interface{}, error) {
return NewService(ic.Emitter), nil
return NewService(ic.Events), nil
},
})
}
type Service struct {
emitter *events.Emitter
timeouts map[string]*time.Timer
events *events.Exchange
}
func NewService(e *events.Emitter) api.EventsServer {
return &Service{emitter: e}
func NewService(events *events.Exchange) api.EventsServer {
return &Service{events: events}
}
func (s *Service) Register(server *grpc.Server) error {
@@ -37,28 +35,36 @@ func (s *Service) Register(server *grpc.Server) error {
return nil
}
func (s *Service) Stream(req *api.StreamEventsRequest, srv api.Events_StreamServer) error {
clientID := fmt.Sprintf("%d", time.Now().UnixNano())
func (s *Service) Subscribe(req *api.SubscribeRequest, srv api.Events_SubscribeServer) error {
ctx, cancel := context.WithCancel(srv.Context())
defer cancel()
filter, err := filters.ParseAll(req.Filters...)
if err != nil {
return errdefs.ToGRPC(err)
}
eventq, errq := s.events.Subscribe(ctx, filter)
for {
e := <-s.emitter.Events(srv.Context(), clientID)
// upon the client event timeout this will be nil; ignore
if e == nil {
select {
case ev := <-eventq:
if err := srv.Send(ev); err != nil {
return errors.Wrapf(err, "failed sending event to subscriber")
}
case err := <-errq:
if err != nil {
return errors.Wrapf(err, "subscription error")
}
return nil
}
if err := srv.Send(e); err != nil {
logrus.WithFields(logrus.Fields{
"client": clientID,
}).Debug("error sending event; unsubscribing client")
s.emitter.Remove(clientID)
return err
}
}
}
func (s *Service) Post(ctx context.Context, r *api.PostEventRequest) (*empty.Empty, error) {
ctx = events.WithTopic(ctx, r.Envelope.Topic)
if err := s.emitter.Post(ctx, r.Envelope); err != nil {
return nil, err
func (s *Service) Publish(ctx context.Context, r *api.PublishRequest) (*empty.Empty, error) {
if err := s.events.Forward(ctx, r.Envelope); err != nil {
return nil, errdefs.ToGRPC(err)
}
return &empty.Empty{}, nil
}

28
services/images/service.go
View File

@@ -24,25 +24,24 @@ func init() {
plugin.MetadataPlugin,
},
Init: func(ic *plugin.InitContext) (interface{}, error) {
e := events.GetPoster(ic.Context)
m, err := ic.Get(plugin.MetadataPlugin)
if err != nil {
return nil, err
}
return NewService(m.(*bolt.DB), e), nil
return NewService(m.(*bolt.DB), ic.Events), nil
},
})
}
type Service struct {
db *bolt.DB
emitter events.Poster
db *bolt.DB
publisher events.Publisher
}
func NewService(db *bolt.DB, evts events.Poster) imagesapi.ImagesServer {
func NewService(db *bolt.DB, publisher events.Publisher) imagesapi.ImagesServer {
return &Service{
db: db,
emitter: evts,
db: db,
publisher: publisher,
}
}
@@ -100,7 +99,7 @@ func (s *Service) Create(ctx context.Context, req *imagesapi.CreateImageRequest)
return nil, errdefs.ToGRPC(err)
}
if err := s.emit(ctx, "/images/create", &eventsapi.ImageCreate{
if err := s.publisher.Publish(ctx, "/images/create", &eventsapi.ImageCreate{
Name: resp.Image.Name,
Labels: resp.Image.Labels,
}); err != nil {
@@ -139,7 +138,7 @@ func (s *Service) Update(ctx context.Context, req *imagesapi.UpdateImageRequest)
return nil, errdefs.ToGRPC(err)
}
if err := s.emit(ctx, "/images/update", &eventsapi.ImageUpdate{
if err := s.publisher.Publish(ctx, "/images/update", &eventsapi.ImageUpdate{
Name: resp.Image.Name,
Labels: resp.Image.Labels,
}); err != nil {
@@ -156,7 +155,7 @@ func (s *Service) Delete(ctx context.Context, req *imagesapi.DeleteImageRequest)
return nil, err
}
if err := s.emit(ctx, "/images/delete", &eventsapi.ImageDelete{
if err := s.publisher.Publish(ctx, "/images/delete", &eventsapi.ImageDelete{
Name: req.Name,
}); err != nil {
return nil, err
@@ -176,12 +175,3 @@ func (s *Service) withStoreView(ctx context.Context, fn func(ctx context.Context
func (s *Service) withStoreUpdate(ctx context.Context, fn func(ctx context.Context, store images.Store) error) error {
return s.db.Update(s.withStore(ctx, fn))
}
func (s *Service) emit(ctx context.Context, topic string, evt interface{}) error {
emitterCtx := events.WithTopic(ctx, topic)
if err := s.emitter.Post(emitterCtx, evt); err != nil {
return err
}
return nil
}

28
services/namespaces/service.go
View File

@@ -25,27 +25,26 @@ func init() {
plugin.MetadataPlugin,
},
Init: func(ic *plugin.InitContext) (interface{}, error) {
e := events.GetPoster(ic.Context)
m, err := ic.Get(plugin.MetadataPlugin)
if err != nil {
return nil, err
}
return NewService(m.(*bolt.DB), e), nil
return NewService(m.(*bolt.DB), ic.Events), nil
},
})
}
type Service struct {
db *bolt.DB
emitter events.Poster
db *bolt.DB
publisher events.Publisher
}
var _ api.NamespacesServer = &Service{}
func NewService(db *bolt.DB, evts events.Poster) api.NamespacesServer {
func NewService(db *bolt.DB, publisher events.Publisher) api.NamespacesServer {
return &Service{
db: db,
emitter: evts,
db: db,
publisher: publisher,
}
}
@@ -119,7 +118,7 @@ func (s *Service) Create(ctx context.Context, req *api.CreateNamespaceRequest) (
return &resp, err
}
if err := s.emit(ctx, "/namespaces/create", &eventsapi.NamespaceCreate{
if err := s.publisher.Publish(ctx, "/namespaces/create", &eventsapi.NamespaceCreate{
Name: req.Namespace.Name,
Labels: req.Namespace.Labels,
}); err != nil {
@@ -172,7 +171,7 @@ func (s *Service) Update(ctx context.Context, req *api.UpdateNamespaceRequest) (
return &resp, err
}
if err := s.emit(ctx, "/namespaces/update", &eventsapi.NamespaceUpdate{
if err := s.publisher.Publish(ctx, "/namespaces/update", &eventsapi.NamespaceUpdate{
Name: req.Namespace.Name,
Labels: req.Namespace.Labels,
}); err != nil {
@@ -189,7 +188,7 @@ func (s *Service) Delete(ctx context.Context, req *api.DeleteNamespaceRequest) (
return &empty.Empty{}, err
}
if err := s.emit(ctx, "/namespaces/delete", &eventsapi.NamespaceDelete{
if err := s.publisher.Publish(ctx, "/namespaces/delete", &eventsapi.NamespaceDelete{
Name: req.Name,
}); err != nil {
return &empty.Empty{}, err
@@ -209,12 +208,3 @@ func (s *Service) withStoreView(ctx context.Context, fn func(ctx context.Context
func (s *Service) withStoreUpdate(ctx context.Context, fn func(ctx context.Context, store namespaces.Store) error) error {
return s.db.Update(s.withStore(ctx, fn))
}
func (s *Service) emit(ctx context.Context, topic string, evt interface{}) error {
emitterCtx := events.WithTopic(ctx, topic)
if err := s.emitter.Post(emitterCtx, evt); err != nil {
return err
}
return nil
}

20
services/snapshot/service.go
View File

@@ -45,11 +45,10 @@ var empty = &protoempty.Empty{}
type service struct {
snapshotters map[string]snapshot.Snapshotter
defaultSnapshotterName string
emitter events.Poster
publisher events.Publisher
}
func newService(ic *plugin.InitContext) (interface{}, error) {
evts := events.GetPoster(ic.Context)
rawSnapshotters, err := ic.GetAll(plugin.SnapshotPlugin)
if err != nil {
return nil, err
@@ -72,7 +71,7 @@ func newService(ic *plugin.InitContext) (interface{}, error) {
return &service{
snapshotters: snapshotters,
defaultSnapshotterName: cfg.Default,
emitter: evts,
publisher: ic.Events,
}, nil
}
@@ -105,7 +104,7 @@ func (s *service) Prepare(ctx context.Context, pr *snapshotapi.PrepareSnapshotRe
return nil, errdefs.ToGRPC(err)
}
if err := s.emit(ctx, "/snapshot/prepare", &eventsapi.SnapshotPrepare{
if err := s.publisher.Publish(ctx, "/snapshot/prepare", &eventsapi.SnapshotPrepare{
Key: pr.Key,
Parent: pr.Parent,
}); err != nil {
@@ -162,7 +161,7 @@ func (s *service) Commit(ctx context.Context, cr *snapshotapi.CommitSnapshotRequ
return nil, errdefs.ToGRPC(err)
}
if err := s.emit(ctx, "/snapshot/commit", &eventsapi.SnapshotCommit{
if err := s.publisher.Publish(ctx, "/snapshot/commit", &eventsapi.SnapshotCommit{
Key: cr.Key,
Name: cr.Name,
}); err != nil {
@@ -183,7 +182,7 @@ func (s *service) Remove(ctx context.Context, rr *snapshotapi.RemoveSnapshotRequ
return nil, errdefs.ToGRPC(err)
}
if err := s.emit(ctx, "/snapshot/remove", &eventsapi.SnapshotRemove{
if err := s.publisher.Publish(ctx, "/snapshot/remove", &eventsapi.SnapshotRemove{
Key: rr.Key,
}); err != nil {
return nil, err
@@ -294,12 +293,3 @@ func fromMounts(mounts []mount.Mount) []*types.Mount {
}
return out
}
func (s *service) emit(ctx context.Context, topic string, evt interface{}) error {
emitterCtx := events.WithTopic(ctx, topic)
if err := s.emitter.Post(emitterCtx, evt); err != nil {
return err
}
return nil
}

26
services/tasks/service.go
View File

@@ -67,20 +67,19 @@ func New(ic *plugin.InitContext) (interface{}, error) {
r := rr.(runtime.Runtime)
runtimes[r.ID()] = r
}
e := events.GetPoster(ic.Context)
return &Service{
runtimes: runtimes,
db: m.(*bolt.DB),
store: cs,
emitter: e,
runtimes: runtimes,
db: m.(*bolt.DB),
store: cs,
publisher: ic.Events,
}, nil
}
type Service struct {
runtimes map[string]runtime.Runtime
db *bolt.DB
store content.Store
emitter events.Poster
runtimes map[string]runtime.Runtime
db *bolt.DB
store content.Store
publisher events.Publisher
}
func (s *Service) Register(server *grpc.Server) error {
@@ -502,12 +501,3 @@ func (s *Service) getRuntime(name string) (runtime.Runtime, error) {
}
return runtime, nil
}
func (s *Service) emit(ctx context.Context, topic string, evt interface{}) error {
emitterCtx := events.WithTopic(ctx, topic)
if err := s.emitter.Post(emitterCtx, evt); err != nil {
return err
}
return nil
}