vbatts
/
registry
forked from mirrors/docker-distribution
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Use go-events package 

TBD: Queue not converted yet

Signed-off-by: Elliot Pahl <elliot.pahl@gmail.com>
This commit is contained in:
Elliot Pahl 2018-03-14 11:08:11 +11:00 committed by Derek McGowan
parent 2d1126ecc1
commit 800cb95821
No known key found for this signature in database
GPG Key ID: F58C5D0A4405ACDB
25 changed files with 1354 additions and 530 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
go.mod
View File

@ -16,6 +16,7 @@ require (
github.com/denverdino/aliyungo v0.0.0-20190125010748-a747050bb1ba
github.com/dgrijalva/jwt-go v0.0.0-20170104182250-a601269ab70c // indirect
github.com/dnaeon/go-vcr v1.0.1 // indirect
github.com/docker/go-events v0.0.0-20190806004212-e31b211e4f1c
github.com/docker/go-metrics v0.0.1
github.com/docker/libtrust v0.0.0-20150114040149-fa567046d9b1
github.com/garyburd/redigo v0.0.0-20150301180006-535138d7bcd7

2
go.sum
View File

@ -35,6 +35,8 @@ github.com/dgrijalva/jwt-go v0.0.0-20170104182250-a601269ab70c h1:KJAnOBuY9cTKVq
github.com/dgrijalva/jwt-go v0.0.0-20170104182250-a601269ab70c/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
github.com/dnaeon/go-vcr v1.0.1 h1:r8L/HqC0Hje5AXMu1ooW8oyQyOFv4GxqpL0nRP7SLLY=
github.com/dnaeon/go-vcr v1.0.1/go.mod h1:aBB1+wY4s93YsC3HHjMBMrwTj2R9FHDzUr9KyGc8n1E=
github.com/docker/go-events v0.0.0-20190806004212-e31b211e4f1c h1:+pKlWGMw7gf6bQ+oDZB4KHQFypsfjYlq/C4rfL7D3g8=
github.com/docker/go-events v0.0.0-20190806004212-e31b211e4f1c/go.mod h1:Uw6UezgYA44ePAFQYUehOuCzmy5zmg/+nl2ZfMWGkpA=
github.com/docker/go-metrics v0.0.1 h1:AgB/0SvBxihN0X8OR4SjsblXkbMvalQ8cjmtKQ2rQV8=
github.com/docker/go-metrics v0.0.1/go.mod h1:cG1hvH2utMXtqgqqYE9plW6lDxS3/5ayHzueweSI3Vw=
github.com/docker/libtrust v0.0.0-20150114040149-fa567046d9b1 h1:ZClxb8laGDf5arXfYcAtECDFgAgHklGI8CxgjHnXKJ4=

5
notifications/bridge.go
View File

@ -8,6 +8,7 @@ import (
"github.com/docker/distribution/context"
"github.com/docker/distribution/reference"
"github.com/docker/distribution/uuid"
events "github.com/docker/go-events"
"github.com/opencontainers/go-digest"
)
@ -17,7 +18,7 @@ type bridge struct {
actor ActorRecord
source SourceRecord
request RequestRecord
sink Sink
sink events.Sink
}
var _ Listener = &bridge{}
@ -32,7 +33,7 @@ type URLBuilder interface {
// using the actor and source. Any urls populated in the events created by
// this bridge will be created using the URLBuilder.
// TODO(stevvooe): Update this to simply take a context.Context object.
func NewBridge(ub URLBuilder, source SourceRecord, actor ActorRecord, request RequestRecord, sink Sink, includeReferences bool) Listener {
func NewBridge(ub URLBuilder, source SourceRecord, actor ActorRecord, request RequestRecord, sink events.Sink, includeReferences bool) Listener {
return &bridge{
ub: ub,
includeReferences: includeReferences,

126
notifications/bridge_test.go
View File

@ -8,6 +8,7 @@ import (
"github.com/docker/distribution/reference"
v2 "github.com/docker/distribution/registry/api/v2"
"github.com/docker/distribution/uuid"
events "github.com/docker/go-events"
"github.com/docker/libtrust"
"github.com/opencontainers/go-digest"
)
@ -46,8 +47,8 @@ var (
)
func TestEventBridgeManifestPulled(t *testing.T) {
l := createTestEnv(t, testSinkFn(func(events ...Event) error {
checkCommonManifest(t, EventActionPull, events...)
l := createTestEnv(t, testSinkFn(func(event events.Event) error {
checkCommonManifest(t, EventActionPull, event)
return nil
}))
@ -59,8 +60,8 @@ func TestEventBridgeManifestPulled(t *testing.T) {
}
func TestEventBridgeManifestPushed(t *testing.T) {
l := createTestEnv(t, testSinkFn(func(events ...Event) error {
checkCommonManifest(t, EventActionPush, events...)
l := createTestEnv(t, testSinkFn(func(event events.Event) error {
checkCommonManifest(t, EventActionPush, event)
return nil
}))
@ -72,10 +73,10 @@ func TestEventBridgeManifestPushed(t *testing.T) {
}
func TestEventBridgeManifestPushedWithTag(t *testing.T) {
l := createTestEnv(t, testSinkFn(func(events ...Event) error {
checkCommonManifest(t, EventActionPush, events...)
if events[0].Target.Tag != "latest" {
t.Fatalf("missing or unexpected tag: %#v", events[0].Target)
l := createTestEnv(t, testSinkFn(func(event events.Event) error {
checkCommonManifest(t, EventActionPush, event)
if event.(Event).Target.Tag != "latest" {
t.Fatalf("missing or unexpected tag: %#v", event.(Event).Target)
}
return nil
@ -88,10 +89,10 @@ func TestEventBridgeManifestPushedWithTag(t *testing.T) {
}
func TestEventBridgeManifestPulledWithTag(t *testing.T) {
l := createTestEnv(t, testSinkFn(func(events ...Event) error {
checkCommonManifest(t, EventActionPull, events...)
if events[0].Target.Tag != "latest" {
t.Fatalf("missing or unexpected tag: %#v", events[0].Target)
l := createTestEnv(t, testSinkFn(func(event events.Event) error {
checkCommonManifest(t, EventActionPull, event)
if event.(Event).Target.Tag != "latest" {
t.Fatalf("missing or unexpected tag: %#v", event.(Event).Target)
}
return nil
@ -104,10 +105,10 @@ func TestEventBridgeManifestPulledWithTag(t *testing.T) {
}
func TestEventBridgeManifestDeleted(t *testing.T) {
l := createTestEnv(t, testSinkFn(func(events ...Event) error {
checkDeleted(t, EventActionDelete, events...)
if events[0].Target.Digest != dgst {
t.Fatalf("unexpected digest on event target: %q != %q", events[0].Target.Digest, dgst)
l := createTestEnv(t, testSinkFn(func(event events.Event) error {
checkDeleted(t, EventActionDelete, event)
if event.(Event).Target.Digest != dgst {
t.Fatalf("unexpected digest on event target: %q != %q", event.(Event).Target.Digest, dgst)
}
return nil
}))
@ -119,10 +120,10 @@ func TestEventBridgeManifestDeleted(t *testing.T) {
}
func TestEventBridgeTagDeleted(t *testing.T) {
l := createTestEnv(t, testSinkFn(func(events ...Event) error {
checkDeleted(t, EventActionDelete, events...)
if events[0].Target.Tag != m.Tag {
t.Fatalf("unexpected tag on event target: %q != %q", events[0].Target.Tag, m.Tag)
l := createTestEnv(t, testSinkFn(func(event events.Event) error {
checkDeleted(t, EventActionDelete, event)
if event.(Event).Target.Tag != m.Tag {
t.Fatalf("unexpected tag on event target: %q != %q", event.(Event).Target.Tag, m.Tag)
}
return nil
}))
@ -134,8 +135,8 @@ func TestEventBridgeTagDeleted(t *testing.T) {
}
func TestEventBridgeRepoDeleted(t *testing.T) {
l := createTestEnv(t, testSinkFn(func(events ...Event) error {
checkDeleted(t, EventActionDelete, events...)
l := createTestEnv(t, testSinkFn(func(event events.Event) error {
checkDeleted(t, EventActionDelete, event)
return nil
}))
@ -162,36 +163,29 @@ func createTestEnv(t *testing.T, fn testSinkFn) Listener {
return NewBridge(ub, source, actor, request, fn, true)
}
func checkDeleted(t *testing.T, action string, events ...Event) {
if len(events) != 1 {
t.Fatalf("unexpected number of events: %v != 1", len(events))
func checkDeleted(t *testing.T, action string, event events.Event) {
if event.(Event).Source != source {
t.Fatalf("source not equal: %#v != %#v", event.(Event).Source, source)
}
event := events[0]
if event.Source != source {
t.Fatalf("source not equal: %#v != %#v", event.Source, source)
if event.(Event).Request != request {
t.Fatalf("request not equal: %#v != %#v", event.(Event).Request, request)
}
if event.Request != request {
t.Fatalf("request not equal: %#v != %#v", event.Request, request)
if event.(Event).Actor != actor {
t.Fatalf("request not equal: %#v != %#v", event.(Event).Actor, actor)
}
if event.Actor != actor {
t.Fatalf("request not equal: %#v != %#v", event.Actor, actor)
}
if event.Target.Repository != repo {
t.Fatalf("unexpected repository: %q != %q", event.Target.Repository, repo)
if event.(Event).Target.Repository != repo {
t.Fatalf("unexpected repository: %q != %q", event.(Event).Target.Repository, repo)
}
}
func checkCommonManifest(t *testing.T, action string, events ...Event) {
checkCommon(t, events...)
func checkCommonManifest(t *testing.T, action string, event events.Event) {
checkCommon(t, event)
event := events[0]
if event.Action != action {
t.Fatalf("unexpected event action: %q != %q", event.Action, action)
if event.(Event).Action != action {
t.Fatalf("unexpected event action: %q != %q", event.(Event).Action, action)
}
repoRef, _ := reference.WithName(repo)
@ -201,57 +195,51 @@ func checkCommonManifest(t *testing.T, action string, events ...Event) {
t.Fatalf("error building expected url: %v", err)
}
if event.Target.URL != u {
t.Fatalf("incorrect url passed: \n%q != \n%q", event.Target.URL, u)
if event.(Event).Target.URL != u {
t.Fatalf("incorrect url passed: \n%q != \n%q", event.(Event).Target.URL, u)
}
if len(event.Target.References) != len(layers) {
t.Fatalf("unexpected number of references %v != %v", len(event.Target.References), len(layers))
if len(event.(Event).Target.References) != len(layers) {
t.Fatalf("unexpected number of references %v != %v", len(event.(Event).Target.References), len(layers))
}
for i, targetReference := range event.Target.References {
for i, targetReference := range event.(Event).Target.References {
if targetReference.Digest != layers[i].BlobSum {
t.Fatalf("unexpected reference: %q != %q", targetReference.Digest, layers[i].BlobSum)
}
}
}
func checkCommon(t *testing.T, events ...Event) {
if len(events) != 1 {
t.Fatalf("unexpected number of events: %v != 1", len(events))
func checkCommon(t *testing.T, event events.Event) {
if event.(Event).Source != source {
t.Fatalf("source not equal: %#v != %#v", event.(Event).Source, source)
}
event := events[0]
if event.Source != source {
t.Fatalf("source not equal: %#v != %#v", event.Source, source)
if event.(Event).Request != request {
t.Fatalf("request not equal: %#v != %#v", event.(Event).Request, request)
}
if event.Request != request {
t.Fatalf("request not equal: %#v != %#v", event.Request, request)
if event.(Event).Actor != actor {
t.Fatalf("request not equal: %#v != %#v", event.(Event).Actor, actor)
}
if event.Actor != actor {
t.Fatalf("request not equal: %#v != %#v", event.Actor, actor)
if event.(Event).Target.Digest != dgst {
t.Fatalf("unexpected digest on event target: %q != %q", event.(Event).Target.Digest, dgst)
}
if event.Target.Digest != dgst {
t.Fatalf("unexpected digest on event target: %q != %q", event.Target.Digest, dgst)
if event.(Event).Target.Length != int64(len(payload)) {
t.Fatalf("unexpected target length: %v != %v", event.(Event).Target.Length, len(payload))
}
if event.Target.Length != int64(len(payload)) {
t.Fatalf("unexpected target length: %v != %v", event.Target.Length, len(payload))
}
if event.Target.Repository != repo {
t.Fatalf("unexpected repository: %q != %q", event.Target.Repository, repo)
if event.(Event).Target.Repository != repo {
t.Fatalf("unexpected repository: %q != %q", event.(Event).Target.Repository, repo)
}
}
type testSinkFn func(events ...Event) error
type testSinkFn func(event events.Event) error
func (tsf testSinkFn) Write(events ...Event) error {
return tsf(events...)
func (tsf testSinkFn) Write(event events.Event) error {
return tsf(event)
}
func (tsf testSinkFn) Close() error { return nil }

5
notifications/endpoint.go
View File

@ -5,6 +5,7 @@ import (
"time"
"github.com/docker/distribution/configuration"
events "github.com/docker/go-events"
)
// EndpointConfig covers the optional configuration parameters for an active
@ -42,7 +43,7 @@ func (ec *EndpointConfig) defaults() {
// services when events are written. Writes are non-blocking and always
// succeed for callers but events may be queued internally.
type Endpoint struct {
Sink
events.Sink
url string
name string
@ -64,7 +65,7 @@ func NewEndpoint(name, url string, config EndpointConfig) *Endpoint {
endpoint.Sink = newHTTPSink(
endpoint.url, endpoint.Timeout, endpoint.Headers,
endpoint.Transport, endpoint.metrics.httpStatusListener())
endpoint.Sink = newRetryingSink(endpoint.Sink, endpoint.Threshold, endpoint.Backoff)
endpoint.Sink = events.NewRetryingSink(endpoint.Sink, events.NewBreaker(endpoint.Threshold, endpoint.Backoff))
endpoint.Sink = newEventQueue(endpoint.Sink, endpoint.metrics.eventQueueListener())
mediaTypes := append(config.Ignore.MediaTypes, config.IgnoredMediaTypes...)
endpoint.Sink = newIgnoredSink(endpoint.Sink, mediaTypes, config.Ignore.Actions)

16
notifications/event.go
View File

@ -5,6 +5,7 @@ import (
"time"
"github.com/docker/distribution"
events "github.com/docker/go-events"
)
// EventAction constants used in action field of Event.
@ -30,7 +31,7 @@ const (
type Envelope struct {
// Events make up the contents of the envelope. Events present in a single
// envelope are not necessarily related.
Events []Event `json:"events,omitempty"`
Events []events.Event `json:"events,omitempty"`
}
// TODO(stevvooe): The event type should be separate from the json format. It
@ -148,16 +149,3 @@ var (
// retries will not be successful.
ErrSinkClosed = fmt.Errorf("sink: closed")
)
// Sink accepts and sends events.
type Sink interface {
// Write writes one or more events to the sink. If no error is returned,
// the caller will assume that all events have been committed and will not
// try to send them again. If an error is received, the caller may retry
// sending the event. The caller should cede the slice of memory to the
// sink and not modify it after calling this method.
Write(events ...Event) error
// Close the sink, possibly waiting for pending events to flush.
Close() error
}

20
notifications/http.go
View File

@ -7,6 +7,8 @@ import (
"net/http"
"sync"
"time"
events "github.com/docker/go-events"
)
// httpSink implements a single-flight, http notification endpoint. This is
@ -45,15 +47,15 @@ func newHTTPSink(u string, timeout time.Duration, headers http.Header, transport
// httpStatusListener is called on various outcomes of sending notifications.
type httpStatusListener interface {
success(status int, events ...Event)
failure(status int, events ...Event)
err(err error, events ...Event)
success(status int, event events.Event)
failure(status int, events events.Event)
err(err error, events events.Event)
}
// Accept makes an attempt to notify the endpoint, returning an error if it
// fails. It is the caller's responsibility to retry on error. The events are
// accepted or rejected as a group.
func (hs *httpSink) Write(events ...Event) error {
func (hs *httpSink) Write(event events.Event) error {
hs.mu.Lock()
defer hs.mu.Unlock()
defer hs.client.Transport.(*headerRoundTripper).CloseIdleConnections()
@ -63,7 +65,7 @@ func (hs *httpSink) Write(events ...Event) error {
}
envelope := Envelope{
Events: events,
Events: []events.Event{event},
}
// TODO(stevvooe): It is not ideal to keep re-encoding the request body on
@ -73,7 +75,7 @@ func (hs *httpSink) Write(events ...Event) error {
p, err := json.MarshalIndent(envelope, "", " ")
if err != nil {
for _, listener := range hs.listeners {
listener.err(err, events...)
listener.err(err, event)
}
return fmt.Errorf("%v: error marshaling event envelope: %v", hs, err)
}
@ -82,7 +84,7 @@ func (hs *httpSink) Write(events ...Event) error {
resp, err := hs.client.Post(hs.url, EventsMediaType, body)
if err != nil {
for _, listener := range hs.listeners {
listener.err(err, events...)
listener.err(err, event)
}
return fmt.Errorf("%v: error posting: %v", hs, err)
@ -94,7 +96,7 @@ func (hs *httpSink) Write(events ...Event) error {
switch {
case resp.StatusCode >= 200 && resp.StatusCode < 400:
for _, listener := range hs.listeners {
listener.success(resp.StatusCode, events...)
listener.success(resp.StatusCode, event)
}
// TODO(stevvooe): This is a little accepting: we may want to support
@ -104,7 +106,7 @@ func (hs *httpSink) Write(events ...Event) error {
return nil
default:
for _, listener := range hs.listeners {
listener.failure(resp.StatusCode, events...)
listener.failure(resp.StatusCode, event)
}
return fmt.Errorf("%v: response status %v unaccepted", hs, resp.Status)
}

55
notifications/http_test.go
View File

@ -14,6 +14,7 @@ import (
"testing"
"github.com/docker/distribution/manifest/schema1"
events "github.com/docker/go-events"
)
// TestHTTPSink mocks out an http endpoint and notifies it under a couple of
@ -68,8 +69,8 @@ func TestHTTPSink(t *testing.T) {
&endpointMetricsHTTPStatusListener{safeMetrics: metrics})
// first make sure that the default transport gives x509 untrusted cert error
events := []Event{}
err := sink.Write(events...)
event := Event{}
err := sink.Write(event)
if !strings.Contains(err.Error(), "x509") && !strings.Contains(err.Error(), "unknown ca") {
t.Fatal("TLS server with default transport should give unknown CA error")
}
@ -83,12 +84,13 @@ func TestHTTPSink(t *testing.T) {
}
sink = newHTTPSink(server.URL, 0, nil, tr,
&endpointMetricsHTTPStatusListener{safeMetrics: metrics})
err = sink.Write(events...)
err = sink.Write(event)
if err != nil {
t.Fatalf("unexpected error writing events: %v", err)
t.Fatalf("unexpected error writing event: %v", err)
}
// reset server to standard http server and sink to a basic sink
metrics = newSafeMetrics("")
server = httptest.NewServer(serverHandler)
sink = newHTTPSink(server.URL, 0, nil, nil,
&endpointMetricsHTTPStatusListener{safeMetrics: metrics})
@ -111,46 +113,52 @@ func TestHTTPSink(t *testing.T) {
}()
for _, tc := range []struct {
events []Event // events to send
event events.Event // events to send
url string
failure bool // true if there should be a failure.
isFailure bool // true if there should be a failure.
isError bool // true if the request returns an error
statusCode int // if not set, no status code should be incremented.
}{
{
statusCode: http.StatusOK,
events: []Event{
createTestEvent("push", "library/test", schema1.MediaTypeSignedManifest)},
event: createTestEvent("push", "library/test", schema1.MediaTypeSignedManifest),
},
{
statusCode: http.StatusOK,
events: []Event{
createTestEvent("push", "library/test", schema1.MediaTypeSignedManifest),
createTestEvent("push", "library/test", layerMediaType),
createTestEvent("push", "library/test", layerMediaType),
},
event: createTestEvent("push", "library/test", schema1.MediaTypeSignedManifest),
},
{
statusCode: http.StatusOK,
event: createTestEvent("push", "library/test", layerMediaType),
},
{
statusCode: http.StatusOK,
event: createTestEvent("push", "library/test", layerMediaType),
},
{
statusCode: http.StatusTemporaryRedirect,
},
{
statusCode: http.StatusBadRequest,
failure: true,
isFailure: true,
},
{
// Case where connection is immediately closed
url: closeL.Addr().String(),
failure: true,
url: "http://" + closeL.Addr().String(),
isError: true,
},
} {
if tc.failure {
expectedMetrics.Failures += len(tc.events)
if tc.isFailure {
expectedMetrics.Failures++
} else if tc.isError {
expectedMetrics.Errors++
} else {
expectedMetrics.Successes += len(tc.events)
expectedMetrics.Successes++
}
if tc.statusCode > 0 {
expectedMetrics.Statuses[fmt.Sprintf("%d %s", tc.statusCode, http.StatusText(tc.statusCode))] += len(tc.events)
expectedMetrics.Statuses[fmt.Sprintf("%d %s", tc.statusCode, http.StatusText(tc.statusCode))]++
}
url := tc.url
@ -161,11 +169,11 @@ func TestHTTPSink(t *testing.T) {
url += fmt.Sprintf("?status=%v", tc.statusCode)
sink.url = url
t.Logf("testcase: %v, fail=%v", url, tc.failure)
t.Logf("testcase: %v, fail=%v, error=%v", url, tc.isFailure, tc.isError)
// Try a simple event emission.
err := sink.Write(tc.events...)
err := sink.Write(tc.event)
if !tc.failure {
if !tc.isFailure && !tc.isError {
if err != nil {
t.Fatalf("unexpected error send event: %v", err)
}
@ -173,6 +181,7 @@ func TestHTTPSink(t *testing.T) {
if err == nil {
t.Fatalf("the endpoint should have rejected the request")
}
t.Logf("write error: %v", err)
}
if !reflect.DeepEqual(metrics.EndpointMetrics, expectedMetrics) {

35
notifications/metrics.go
View File

@ -7,6 +7,7 @@ import (
"sync"
prometheus "github.com/docker/distribution/metrics"
events "github.com/docker/go-events"
"github.com/docker/go-metrics"
)
@ -70,32 +71,32 @@ type endpointMetricsHTTPStatusListener struct {
var _ httpStatusListener = &endpointMetricsHTTPStatusListener{}
func (emsl *endpointMetricsHTTPStatusListener) success(status int, events ...Event) {
func (emsl *endpointMetricsHTTPStatusListener) success(status int, event events.Event) {
emsl.safeMetrics.Lock()
defer emsl.safeMetrics.Unlock()
emsl.Statuses[fmt.Sprintf("%d %s", status, http.StatusText(status))] += len(events)
emsl.Successes += len(events)
emsl.Statuses[fmt.Sprintf("%d %s", status, http.StatusText(status))]++
emsl.Successes++
statusCounter.WithValues(fmt.Sprintf("%d %s", status, http.StatusText(status)), emsl.EndpointName).Inc(1)
eventsCounter.WithValues("Successes", emsl.EndpointName).Inc(float64(len(events)))
eventsCounter.WithValues("Successes", emsl.EndpointName).Inc(1)
}
func (emsl *endpointMetricsHTTPStatusListener) failure(status int, events ...Event) {
func (emsl *endpointMetricsHTTPStatusListener) failure(status int, event events.Event) {
emsl.safeMetrics.Lock()
defer emsl.safeMetrics.Unlock()
emsl.Statuses[fmt.Sprintf("%d %s", status, http.StatusText(status))] += len(events)
emsl.Failures += len(events)
emsl.Statuses[fmt.Sprintf("%d %s", status, http.StatusText(status))]++
emsl.Failures++
statusCounter.WithValues(fmt.Sprintf("%d %s", status, http.StatusText(status)), emsl.EndpointName).Inc(1)
eventsCounter.WithValues("Failures", emsl.EndpointName).Inc(float64(len(events)))
eventsCounter.WithValues("Failures", emsl.EndpointName).Inc(1)
}
func (emsl *endpointMetricsHTTPStatusListener) err(err error, events ...Event) {
func (emsl *endpointMetricsHTTPStatusListener) err(err error, event events.Event) {
emsl.safeMetrics.Lock()
defer emsl.safeMetrics.Unlock()
emsl.Errors += len(events)
emsl.Errors++
eventsCounter.WithValues("Errors", emsl.EndpointName).Inc(float64(len(events)))
eventsCounter.WithValues("Errors", emsl.EndpointName).Inc(1)
}
// endpointMetricsEventQueueListener maintains the incoming events counter and
@ -104,20 +105,20 @@ type endpointMetricsEventQueueListener struct {
*safeMetrics
}
func (eqc *endpointMetricsEventQueueListener) ingress(events ...Event) {
func (eqc *endpointMetricsEventQueueListener) ingress(event events.Event) {
eqc.Lock()
defer eqc.Unlock()
eqc.Events += len(events)
eqc.Pending += len(events)
eqc.Events++
eqc.Pending++
eventsCounter.WithValues("Events", eqc.EndpointName).Inc()
pendingGauge.WithValues(eqc.EndpointName).Inc(float64(len(events)))
pendingGauge.WithValues(eqc.EndpointName).Inc(1)
}
func (eqc *endpointMetricsEventQueueListener) egress(events ...Event) {
func (eqc *endpointMetricsEventQueueListener) egress(event events.Event) {
eqc.Lock()
defer eqc.Unlock()
eqc.Pending -= len(events)
eqc.Pending--
pendingGauge.WithValues(eqc.EndpointName).Dec(1)
}

263
notifications/sinks.go
View File

@ -4,107 +4,16 @@ import (
"container/list"
"fmt"
"sync"
"time"
events "github.com/docker/go-events"
"github.com/sirupsen/logrus"
)
// NOTE(stevvooe): This file contains definitions for several utility sinks.
// Typically, the broadcaster is the only sink that should be required
// externally, but others are suitable for export if the need arises. Albeit,
// the tight integration with endpoint metrics should be removed.
// Broadcaster sends events to multiple, reliable Sinks. The goal of this
// component is to dispatch events to configured endpoints. Reliability can be
// provided by wrapping incoming sinks.
type Broadcaster struct {
sinks []Sink
events chan []Event
closed chan chan struct{}
}
// NewBroadcaster ...
// Add appends one or more sinks to the list of sinks. The broadcaster
// behavior will be affected by the properties of the sink. Generally, the
// sink should accept all messages and deal with reliability on its own. Use
// of EventQueue and RetryingSink should be used here.
func NewBroadcaster(sinks ...Sink) *Broadcaster {
b := Broadcaster{
sinks: sinks,
events: make(chan []Event),
closed: make(chan chan struct{}),
}
// Start the broadcaster
go b.run()
return &b
}
// Write accepts a block of events to be dispatched to all sinks. This method
// will never fail and should never block (hopefully!). The caller cedes the
// slice memory to the broadcaster and should not modify it after calling
// write.
func (b *Broadcaster) Write(events ...Event) error {
select {
case b.events <- events:
case <-b.closed:
return ErrSinkClosed
}
return nil
}
// Close the broadcaster, ensuring that all messages are flushed to the
// underlying sink before returning.
func (b *Broadcaster) Close() error {
logrus.Infof("broadcaster: closing")
select {
case <-b.closed:
// already closed
return fmt.Errorf("broadcaster: already closed")
default:
// do a little chan handoff dance to synchronize closing
closed := make(chan struct{})
b.closed <- closed
close(b.closed)
<-closed
return nil
}
}
// run is the main broadcast loop, started when the broadcaster is created.
// Under normal conditions, it waits for events on the event channel. After
// Close is called, this goroutine will exit.
func (b *Broadcaster) run() {
for {
select {
case block := <-b.events:
for _, sink := range b.sinks {
if err := sink.Write(block...); err != nil {
logrus.Errorf("broadcaster: error writing events to %v, these events will be lost: %v", sink, err)
}
}
case closing := <-b.closed:
// close all the underlying sinks
for _, sink := range b.sinks {
if err := sink.Close(); err != nil {
logrus.Errorf("broadcaster: error closing sink %v: %v", sink, err)
}
}
closing <- struct{}{}
logrus.Debugf("broadcaster: closed")
return
}
}
}
// eventQueue accepts all messages into a queue for asynchronous consumption
// by a sink. It is unbounded and thread safe but the sink must be reliable or
// events will be dropped.
type eventQueue struct {
sink Sink
sink events.Sink
events *list.List
listeners []eventQueueListener
cond *sync.Cond
@ -114,13 +23,13 @@ type eventQueue struct {
// eventQueueListener is called when various events happen on the queue.
type eventQueueListener interface {
ingress(events ...Event)
egress(events ...Event)
ingress(event events.Event)
egress(event events.Event)
}
// newEventQueue returns a queue to the provided sink. If the updater is non-
// nil, it will be called to update pending metrics on ingress and egress.
func newEventQueue(sink Sink, listeners ...eventQueueListener) *eventQueue {
func newEventQueue(sink events.Sink, listeners ...eventQueueListener) *eventQueue {
eq := eventQueue{
sink: sink,
events: list.New(),
@ -134,7 +43,7 @@ func newEventQueue(sink Sink, listeners ...eventQueueListener) *eventQueue {
// Write accepts the events into the queue, only failing if the queue has
// beend closed.
func (eq *eventQueue) Write(events ...Event) error {
func (eq *eventQueue) Write(event events.Event) error {
eq.mu.Lock()
defer eq.mu.Unlock()
@ -143,9 +52,9 @@ func (eq *eventQueue) Write(events ...Event) error {
}
for _, listener := range eq.listeners {
listener.ingress(events...)
listener.ingress(event)
}
eq.events.PushBack(events)
eq.events.PushBack(event)
eq.cond.Signal() // signal waiters
return nil
@ -171,18 +80,18 @@ func (eq *eventQueue) Close() error {
// run is the main goroutine to flush events to the target sink.
func (eq *eventQueue) run() {
for {
block := eq.next()
event := eq.next()
if block == nil {
if event == nil {
return // nil block means event queue is closed.
}
if err := eq.sink.Write(block...); err != nil {
if err := eq.sink.Write(event); err != nil {
logrus.Warnf("eventqueue: error writing events to %v, these events will be lost: %v", eq.sink, err)
}
for _, listener := range eq.listeners {
listener.egress(block...)
listener.egress(event)
}
}
}
@ -190,7 +99,7 @@ func (eq *eventQueue) run() {
// next encompasses the critical section of the run loop. When the queue is
// empty, it will block on the condition. If new data arrives, it will wake
// and return a block. When closed, a nil slice will be returned.
func (eq *eventQueue) next() []Event {
func (eq *eventQueue) next() events.Event {
eq.mu.Lock()
defer eq.mu.Unlock()
@ -204,7 +113,7 @@ func (eq *eventQueue) next() []Event {
}
front := eq.events.Front()
block := front.Value.([]Event)
block := front.Value.(events.Event)
eq.events.Remove(front)
return block
@ -213,12 +122,12 @@ func (eq *eventQueue) next() []Event {
// ignoredSink discards events with ignored target media types and actions.
// passes the rest along.
type ignoredSink struct {
Sink
events.Sink
ignoreMediaTypes map[string]bool
ignoreActions map[string]bool
}
func newIgnoredSink(sink Sink, ignored []string, ignoreActions []string) Sink {
func newIgnoredSink(sink events.Sink, ignored []string, ignoreActions []string) events.Sink {
if len(ignored) == 0 {
return sink
}
@ -242,146 +151,14 @@ func newIgnoredSink(sink Sink, ignored []string, ignoreActions []string) Sink {
// Write discards events with ignored target media types and passes the rest
// along.
func (imts *ignoredSink) Write(events ...Event) error {
var kept []Event
for _, e := range events {
if !imts.ignoreMediaTypes[e.Target.MediaType] {
kept = append(kept, e)
}
}
if len(kept) == 0 {
func (imts *ignoredSink) Write(event events.Event) error {
if imts.ignoreMediaTypes[event.(Event).Target.MediaType] || imts.ignoreActions[event.(Event).Action] {
return nil
}
var results []Event
for _, e := range kept {
if !imts.ignoreActions[e.Action] {
results = append(results, e)
}
}
if len(results) == 0 {
return nil
}
return imts.Sink.Write(results...)
return imts.Sink.Write(event)
}
// retryingSink retries the write until success or an ErrSinkClosed is
// returned. Underlying sink must have p > 0 of succeeding or the sink will
// block. Internally, it is a circuit breaker retries to manage reset.
// Concurrent calls to a retrying sink are serialized through the sink,
// meaning that if one is in-flight, another will not proceed.
type retryingSink struct {
mu sync.Mutex
sink Sink
closed bool
// circuit breaker heuristics
failures struct {
threshold int
recent int
last time.Time
backoff time.Duration // time after which we retry after failure.
}
}
// TODO(stevvooe): We are using circuit break here, which actually doesn't
// make a whole lot of sense for this use case, since we always retry. Move
// this to use bounded exponential backoff.
// newRetryingSink returns a sink that will retry writes to a sink, backing
// off on failure. Parameters threshold and backoff adjust the behavior of the
// circuit breaker.
func newRetryingSink(sink Sink, threshold int, backoff time.Duration) *retryingSink {
rs := &retryingSink{
sink: sink,
}
rs.failures.threshold = threshold
rs.failures.backoff = backoff
return rs
}
// Write attempts to flush the events to the downstream sink until it succeeds
// or the sink is closed.
func (rs *retryingSink) Write(events ...Event) error {
rs.mu.Lock()
defer rs.mu.Unlock()
retry:
if rs.closed {
return ErrSinkClosed
}
if !rs.proceed() {
logrus.Warnf("%v encountered too many errors, backing off", rs.sink)
rs.wait(rs.failures.backoff)
goto retry
}
if err := rs.write(events...); err != nil {
if err == ErrSinkClosed {
// terminal!
return err
}
logrus.Errorf("retryingsink: error writing events: %v, retrying", err)
goto retry
}
func (imts *ignoredSink) Close() error {
return nil
}
// Close closes the sink and the underlying sink.
func (rs *retryingSink) Close() error {
rs.mu.Lock()
defer rs.mu.Unlock()
if rs.closed {
return fmt.Errorf("retryingsink: already closed")
}
rs.closed = true
return rs.sink.Close()
}
// write provides a helper that dispatches failure and success properly. Used
// by write as the single-flight write call.
func (rs *retryingSink) write(events ...Event) error {
if err := rs.sink.Write(events...); err != nil {
rs.failure()
return err
}
rs.reset()
return nil
}
// wait backoff time against the sink, unlocking so others can proceed. Should
// only be called by methods that currently have the mutex.
func (rs *retryingSink) wait(backoff time.Duration) {
rs.mu.Unlock()
defer rs.mu.Lock()
// backoff here
time.Sleep(backoff)
}
// reset marks a successful call.
func (rs *retryingSink) reset() {
rs.failures.recent = 0
rs.failures.last = time.Time{}
}
// failure records a failure.
func (rs *retryingSink) failure() {
rs.failures.recent++
rs.failures.last = time.Now().UTC()
}
// proceed returns true if the call should proceed based on circuit breaker
// heuristics.
func (rs *retryingSink) proceed() bool {
return rs.failures.recent < rs.failures.threshold ||
time.Now().UTC().After(rs.failures.last.Add(rs.failures.backoff))
}

202
notifications/sinks_test.go
View File

@ -1,68 +1,17 @@
package notifications
import (
"fmt"
"math/rand"
"reflect"
"sync"
"time"
events "github.com/docker/go-events"
"github.com/sirupsen/logrus"
"testing"
)
func TestBroadcaster(t *testing.T) {
const nEvents = 1000
var sinks []Sink
for i := 0; i < 10; i++ {
sinks = append(sinks, &testSink{})
}
b := NewBroadcaster(sinks...)
var block []Event
var wg sync.WaitGroup
for i := 1; i <= nEvents; i++ {
block = append(block, createTestEvent("push", "library/test", "blob"))
if i%10 == 0 && i > 0 {
wg.Add(1)
go func(block ...Event) {
if err := b.Write(block...); err != nil {
t.Errorf("error writing block of length %d: %v", len(block), err)
}
wg.Done()
}(block...)
block = nil
}
}
wg.Wait() // Wait until writes complete
if t.Failed() {
t.FailNow()
}
checkClose(t, b)
// Iterate through the sinks and check that they all have the expected length.
for _, sink := range sinks {
ts := sink.(*testSink)
ts.mu.Lock()
defer ts.mu.Unlock()
if len(ts.events) != nEvents {
t.Fatalf("not all events ended up in testsink: len(testSink) == %d, not %d", len(ts.events), nEvents)
}
if !ts.closed {
t.Fatalf("sink should have been closed")
}
}
}
func TestEventQueue(t *testing.T) {
const nevents = 1000
var ts testSink
@ -75,20 +24,16 @@ func TestEventQueue(t *testing.T) {
}, metrics.eventQueueListener())
var wg sync.WaitGroup
var block []Event
var event events.Event
for i := 1; i <= nevents; i++ {
block = append(block, createTestEvent("push", "library/test", "blob"))
if i%10 == 0 && i > 0 {
wg.Add(1)
go func(block ...Event) {
if err := eq.Write(block...); err != nil {
t.Errorf("error writing event block: %v", err)
}
wg.Done()
}(block...)
block = nil
}
event = createTestEvent("push", "library/test", "blob")
wg.Add(1)
go func(event events.Event) {
if err := eq.Write(event); err != nil {
t.Errorf("error writing event block: %v", err)
}
wg.Done()
}(event)
}
wg.Wait()
@ -102,8 +47,8 @@ func TestEventQueue(t *testing.T) {
metrics.Lock()
defer metrics.Unlock()
if len(ts.events) != nevents {
t.Fatalf("events did not make it to the sink: %d != %d", len(ts.events), 1000)
if ts.count != nevents {
t.Fatalf("events did not make it to the sink: %d != %d", ts.count, 1000)
}
if !ts.closed {
@ -126,16 +71,14 @@ func TestIgnoredSink(t *testing.T) {
type testcase struct {
ignoreMediaTypes []string
ignoreActions []string
expected []Event
expected events.Event
}
cases := []testcase{
{nil, nil, []Event{blob, manifest}},
{[]string{"other"}, []string{"other"}, []Event{blob, manifest}},
{[]string{"blob"}, []string{"other"}, []Event{manifest}},
{nil, nil, blob},
{[]string{"other"}, []string{"other"}, blob},
{[]string{"blob", "manifest"}, []string{"other"}, nil},
{[]string{"other"}, []string{"push"}, []Event{manifest}},
{[]string{"other"}, []string{"pull"}, []Event{blob}},
{[]string{"other"}, []string{"pull"}, blob},
{[]string{"other"}, []string{"pull", "push"}, nil},
}
@ -143,78 +86,54 @@ func TestIgnoredSink(t *testing.T) {
ts := &testSink{}
s := newIgnoredSink(ts, c.ignoreMediaTypes, c.ignoreActions)
if err := s.Write(blob, manifest); err != nil {
if err := s.Write(blob); err != nil {
t.Fatalf("error writing event: %v", err)
}
ts.mu.Lock()
if !reflect.DeepEqual(ts.events, c.expected) {
t.Fatalf("unexpected events: %#v != %#v", ts.events, c.expected)
if !reflect.DeepEqual(ts.event, c.expected) {
t.Fatalf("unexpected event: %#v != %#v", ts.event, c.expected)
}
ts.mu.Unlock()
}
cases = []testcase{
{nil, nil, manifest},
{[]string{"other"}, []string{"other"}, manifest},
{[]string{"blob"}, []string{"other"}, manifest},
{[]string{"blob", "manifest"}, []string{"other"}, nil},
{[]string{"other"}, []string{"push"}, manifest},
{[]string{"other"}, []string{"pull", "push"}, nil},
}
for _, c := range cases {
ts := &testSink{}
s := newIgnoredSink(ts, c.ignoreMediaTypes, c.ignoreActions)
if err := s.Write(manifest); err != nil {
t.Fatalf("error writing event: %v", err)
}
ts.mu.Lock()
if !reflect.DeepEqual(ts.event, c.expected) {
t.Fatalf("unexpected event: %#v != %#v", ts.event, c.expected)
}
ts.mu.Unlock()
}
}
func TestRetryingSink(t *testing.T) {
// Make a sync that fails most of the time, ensuring that all the events
// make it through.
var ts testSink
flaky := &flakySink{
rate: 1.0, // start out always failing.
Sink: &ts,
}
s := newRetryingSink(flaky, 3, 10*time.Millisecond)
var wg sync.WaitGroup
var block []Event
for i := 1; i <= 100; i++ {
block = append(block, createTestEvent("push", "library/test", "blob"))
// Above 50, set the failure rate lower
if i > 50 {
s.mu.Lock()
flaky.rate = 0.90
s.mu.Unlock()
}
if i%10 == 0 && i > 0 {
wg.Add(1)
go func(block ...Event) {
defer wg.Done()
if err := s.Write(block...); err != nil {
t.Errorf("error writing event block: %v", err)
}
}(block...)
block = nil
}
}
wg.Wait()
if t.Failed() {
t.FailNow()
}
checkClose(t, s)
ts.mu.Lock()
defer ts.mu.Unlock()
if len(ts.events) != 100 {
t.Fatalf("events not propagated: %d != %d", len(ts.events), 100)
}
}
type testSink struct {
events []Event
event events.Event
count int
mu sync.Mutex
closed bool
}
func (ts *testSink) Write(events ...Event) error {
func (ts *testSink) Write(event events.Event) error {
ts.mu.Lock()
defer ts.mu.Unlock()
ts.events = append(ts.events, events...)
ts.event = event
ts.count++
return nil
}
@ -228,29 +147,16 @@ func (ts *testSink) Close() error {
}
type delayedSink struct {
Sink
events.Sink
delay time.Duration
}
func (ds *delayedSink) Write(events ...Event) error {
func (ds *delayedSink) Write(event events.Event) error {
time.Sleep(ds.delay)
return ds.Sink.Write(events...)
return ds.Sink.Write(event)
}
type flakySink struct {
Sink
rate float64
}
func (fs *flakySink) Write(events ...Event) error {
if rand.Float64() < fs.rate {
return fmt.Errorf("error writing %d events", len(events))
}
return fs.Sink.Write(events...)
}
func checkClose(t *testing.T, sink Sink) {
func checkClose(t *testing.T, sink events.Sink) {
if err := sink.Close(); err != nil {
t.Fatalf("unexpected error closing: %v", err)
}
@ -261,7 +167,7 @@ func checkClose(t *testing.T, sink Sink) {
}
// Write after closed should be an error
if err := sink.Write([]Event{}...); err == nil {
if err := sink.Write(Event{}); err == nil {
t.Fatalf("write after closed did not have an error")
} else if err != ErrSinkClosed {
t.Fatalf("error should be ErrSinkClosed")

7
registry/handlers/app.go
View File

@ -36,6 +36,7 @@ import (
"github.com/docker/distribution/registry/storage/driver/factory"
storagemiddleware "github.com/docker/distribution/registry/storage/driver/middleware"
"github.com/docker/distribution/version"
events "github.com/docker/go-events"
"github.com/docker/go-metrics"
"github.com/docker/libtrust"
"github.com/garyburd/redigo/redis"
@ -70,7 +71,7 @@ type App struct {
// events contains notification related configuration.
events struct {
sink notifications.Sink
sink events.Sink
source notifications.SourceRecord
}
@ -446,7 +447,7 @@ func (app *App) register(routeName string, dispatch dispatchFunc) {
// configureEvents prepares the event sink for action.
func (app *App) configureEvents(configuration *configuration.Configuration) {
// Configure all of the endpoint sinks.
var sinks []notifications.Sink
var sinks []events.Sink
for _, endpoint := range configuration.Notifications.Endpoints {
if endpoint.Disabled {
dcontext.GetLogger(app).Infof("endpoint %s disabled, skipping", endpoint.Name)
@ -470,7 +471,7 @@ func (app *App) configureEvents(configuration *configuration.Configuration) {
// replacing broadcaster with a rabbitmq implementation. It's recommended
// that the registry instances also act as the workers to keep deployment
// simple.
app.events.sink = notifications.NewBroadcaster(sinks...)
app.events.sink = events.NewBroadcaster(sinks...)
// Populate registry event source
hostname, err := os.Hostname()

24
vendor/github.com/docker/go-events/.gitignore generated vendored Normal file
View File

@ -0,0 +1,24 @@
# Compiled Object files, Static and Dynamic libs (Shared Objects)
*.o
*.a
*.so
# Folders
_obj
_test
# Architecture specific extensions/prefixes
*.[568vq]
[568vq].out
*.cgo1.go
*.cgo2.c
_cgo_defun.c
_cgo_gotypes.go
_cgo_export.*
_testmain.go
*.exe
*.test
*.prof

70
vendor/github.com/docker/go-events/CONTRIBUTING.md generated vendored Normal file
View File

@ -0,0 +1,70 @@
# Contributing to Docker open source projects
Want to hack on go-events? Awesome! Here are instructions to get you started.
go-events is part of the [Docker](https://www.docker.com) project, and
follows the same rules and principles. If you're already familiar with the way
Docker does things, you'll feel right at home.
Otherwise, go read Docker's
[contributions guidelines](https://github.com/docker/docker/blob/master/CONTRIBUTING.md),
[issue triaging](https://github.com/docker/docker/blob/master/project/ISSUE-TRIAGE.md),
[review process](https://github.com/docker/docker/blob/master/project/REVIEWING.md) and
[branches and tags](https://github.com/docker/docker/blob/master/project/BRANCHES-AND-TAGS.md).
For an in-depth description of our contribution process, visit the
contributors guide: [Understand how to contribute](https://docs.docker.com/opensource/workflow/make-a-contribution/)
### Sign your work
The sign-off is a simple line at the end of the explanation for the patch. Your
signature certifies that you wrote the patch or otherwise have the right to pass
it on as an open-source patch. The rules are pretty simple: if you can certify
the below (from [developercertificate.org](http://developercertificate.org/)):
```
Developer Certificate of Origin
Version 1.1
Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
660 York Street, Suite 102,
San Francisco, CA 94110 USA
Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.
Developer's Certificate of Origin 1.1
By making a contribution to this project, I certify that:
(a) The contribution was created in whole or in part by me and I
have the right to submit it under the open source license
indicated in the file; or
(b) The contribution is based upon previous work that, to the best
of my knowledge, is covered under an appropriate open source
license and I have the right under that license to submit that
work with modifications, whether created in whole or in part
by me, under the same open source license (unless I am
permitted to submit under a different license), as indicated
in the file; or
(c) The contribution was provided directly to me by some other
person who certified (a), (b) or (c) and I have not modified
it.
(d) I understand and agree that this project and the contribution
are public and that a record of the contribution (including all
personal information I submit with it, including my sign-off) is
maintained indefinitely and may be redistributed consistent with
this project or the open source license(s) involved.
```
Then you just add a line to every git commit message:
Signed-off-by: Joe Smith <joe.smith@email.com>
Use your real name (sorry, no pseudonyms or anonymous contributions.)
If you set your `user.name` and `user.email` git configs, you can sign your
commit automatically with `git commit -s`.

201
vendor/github.com/docker/go-events/LICENSE generated vendored Normal file
View File

@ -0,0 +1,201 @@
Apache License
Version 2.0, January 2004
http://www.apache.org/licenses/
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
1. Definitions.
"License" shall mean the terms and conditions for use, reproduction,
and distribution as defined by Sections 1 through 9 of this document.
"Licensor" shall mean the copyright owner or entity authorized by
the copyright owner that is granting the License.
"Legal Entity" shall mean the union of the acting entity and all
other entities that control, are controlled by, or are under common
control with that entity. For the purposes of this definition,
"control" means (i) the power, direct or indirect, to cause the
direction or management of such entity, whether by contract or
otherwise, or (ii) ownership of fifty percent (50%) or more of the
outstanding shares, or (iii) beneficial ownership of such entity.
"You" (or "Your") shall mean an individual or Legal Entity
exercising permissions granted by this License.
"Source" form shall mean the preferred form for making modifications,
including but not limited to software source code, documentation
source, and configuration files.
"Object" form shall mean any form resulting from mechanical
transformation or translation of a Source form, including but
not limited to compiled object code, generated documentation,
and conversions to other media types.
"Work" shall mean the work of authorship, whether in Source or
Object form, made available under the License, as indicated by a
copyright notice that is included in or attached to the work
(an example is provided in the Appendix below).
"Derivative Works" shall mean any work, whether in Source or Object
form, that is based on (or derived from) the Work and for which the
editorial revisions, annotations, elaborations, or other modifications
represent, as a whole, an original work of authorship. For the purposes
of this License, Derivative Works shall not include works that remain
separable from, or merely link (or bind by name) to the interfaces of,
the Work and Derivative Works thereof.
"Contribution" shall mean any work of authorship, including
the original version of the Work and any modifications or additions
to that Work or Derivative Works thereof, that is intentionally
submitted to Licensor for inclusion in the Work by the copyright owner
or by an individual or Legal Entity authorized to submit on behalf of
the copyright owner. For the purposes of this definition, "submitted"
means any form of electronic, verbal, or written communication sent
to the Licensor or its representatives, including but not limited to
communication on electronic mailing lists, source code control systems,
and issue tracking systems that are managed by, or on behalf of, the
Licensor for the purpose of discussing and improving the Work, but
excluding communication that is conspicuously marked or otherwise
designated in writing by the copyright owner as "Not a Contribution."
"Contributor" shall mean Licensor and any individual or Legal Entity
on behalf of whom a Contribution has been received by Licensor and
subsequently incorporated within the Work.
2. Grant of Copyright License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
copyright license to reproduce, prepare Derivative Works of,
publicly display, publicly perform, sublicense, and distribute the
Work and such Derivative Works in Source or Object form.
3. Grant of Patent License. Subject to the terms and conditions of
this License, each Contributor hereby grants to You a perpetual,
worldwide, non-exclusive, no-charge, royalty-free, irrevocable
(except as stated in this section) patent license to make, have made,
use, offer to sell, sell, import, and otherwise transfer the Work,
where such license applies only to those patent claims licensable
by such Contributor that are necessarily infringed by their
Contribution(s) alone or by combination of their Contribution(s)
with the Work to which such Contribution(s) was submitted. If You
institute patent litigation against any entity (including a
cross-claim or counterclaim in a lawsuit) alleging that the Work
or a Contribution incorporated within the Work constitutes direct
or contributory patent infringement, then any patent licenses
granted to You under this License for that Work shall terminate
as of the date such litigation is filed.
4. Redistribution. You may reproduce and distribute copies of the
Work or Derivative Works thereof in any medium, with or without
modifications, and in Source or Object form, provided that You
meet the following conditions:
(a) You must give any other recipients of the Work or
Derivative Works a copy of this License; and
(b) You must cause any modified files to carry prominent notices
stating that You changed the files; and
(c) You must retain, in the Source form of any Derivative Works
that You distribute, all copyright, patent, trademark, and
attribution notices from the Source form of the Work,
excluding those notices that do not pertain to any part of
the Derivative Works; and
(d) If the Work includes a "NOTICE" text file as part of its
distribution, then any Derivative Works that You distribute must
include a readable copy of the attribution notices contained
within such NOTICE file, excluding those notices that do not
pertain to any part of the Derivative Works, in at least one
of the following places: within a NOTICE text file distributed
as part of the Derivative Works; within the Source form or
documentation, if provided along with the Derivative Works; or,
within a display generated by the Derivative Works, if and
wherever such third-party notices normally appear. The contents
of the NOTICE file are for informational purposes only and
do not modify the License. You may add Your own attribution
notices within Derivative Works that You distribute, alongside
or as an addendum to the NOTICE text from the Work, provided
that such additional attribution notices cannot be construed
as modifying the License.
You may add Your own copyright statement to Your modifications and
may provide additional or different license terms and conditions
for use, reproduction, or distribution of Your modifications, or
for any such Derivative Works as a whole, provided Your use,
reproduction, and distribution of the Work otherwise complies with
the conditions stated in this License.
5. Submission of Contributions. Unless You explicitly state otherwise,
any Contribution intentionally submitted for inclusion in the Work
by You to the Licensor shall be under the terms and conditions of
this License, without any additional terms or conditions.
Notwithstanding the above, nothing herein shall supersede or modify
the terms of any separate license agreement you may have executed
with Licensor regarding such Contributions.
6. Trademarks. This License does not grant permission to use the trade
names, trademarks, service marks, or product names of the Licensor,
except as required for reasonable and customary use in describing the
origin of the Work and reproducing the content of the NOTICE file.
7. Disclaimer of Warranty. Unless required by applicable law or
agreed to in writing, Licensor provides the Work (and each
Contributor provides its Contributions) on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
implied, including, without limitation, any warranties or conditions
of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
PARTICULAR PURPOSE. You are solely responsible for determining the
appropriateness of using or redistributing the Work and assume any
risks associated with Your exercise of permissions under this License.
8. Limitation of Liability. In no event and under no legal theory,
whether in tort (including negligence), contract, or otherwise,
unless required by applicable law (such as deliberate and grossly
negligent acts) or agreed to in writing, shall any Contributor be
liable to You for damages, including any direct, indirect, special,
incidental, or consequential damages of any character arising as a
result of this License or out of the use or inability to use the
Work (including but not limited to damages for loss of goodwill,
work stoppage, computer failure or malfunction, or any and all
other commercial damages or losses), even if such Contributor
has been advised of the possibility of such damages.
9. Accepting Warranty or Additional Liability. While redistributing
the Work or Derivative Works thereof, You may choose to offer,
and charge a fee for, acceptance of support, warranty, indemnity,
or other liability obligations and/or rights consistent with this
License. However, in accepting such obligations, You may act only
on Your own behalf and on Your sole responsibility, not on behalf
of any other Contributor, and only if You agree to indemnify,
defend, and hold each Contributor harmless for any liability
incurred by, or claims asserted against, such Contributor by reason
of your accepting any such warranty or additional liability.
END OF TERMS AND CONDITIONS
APPENDIX: How to apply the Apache License to your work.
To apply the Apache License to your work, attach the following
boilerplate notice, with the fields enclosed by brackets "{}"
replaced with your own identifying information. (Don't include
the brackets!) The text should be enclosed in the appropriate
comment syntax for the file format. We also recommend that a
file or class name and description of purpose be included on the
same "printed page" as the copyright notice for easier
identification within third-party archives.
Copyright 2016 Docker, Inc.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

46
vendor/github.com/docker/go-events/MAINTAINERS generated vendored Normal file
View File

@ -0,0 +1,46 @@
# go-events maintainers file
#
# This file describes who runs the docker/go-events project and how.
# This is a living document - if you see something out of date or missing, speak up!
#
# It is structured to be consumable by both humans and programs.
# To extract its contents programmatically, use any TOML-compliant parser.
#
# This file is compiled into the MAINTAINERS file in docker/opensource.
#
[Org]
[Org."Core maintainers"]
people = [
"aaronlehmann",
"aluzzardi",
"lk4d4",
"stevvooe",
]
[people]
# A reference list of all people associated with the project.
# All other sections should refer to people by their canonical key
# in the people section.
# ADD YOURSELF HERE IN ALPHABETICAL ORDER
[people.aaronlehmann]
Name = "Aaron Lehmann"
Email = "aaron.lehmann@docker.com"
GitHub = "aaronlehmann"
[people.aluzzardi]
Name = "Andrea Luzzardi"
Email = "al@docker.com"
GitHub = "aluzzardi"
[people.lk4d4]
Name = "Alexander Morozov"
Email = "lk4d4@docker.com"
GitHub = "lk4d4"
[people.stevvooe]
Name = "Stephen Day"
Email = "stephen.day@docker.com"
GitHub = "stevvooe"

117
vendor/github.com/docker/go-events/README.md generated vendored Normal file
View File

@ -0,0 +1,117 @@
# Docker Events Package
[![GoDoc](https://godoc.org/github.com/docker/go-events?status.svg)](https://godoc.org/github.com/docker/go-events)
[![Circle CI](https://circleci.com/gh/docker/go-events.svg?style=shield)](https://circleci.com/gh/docker/go-events)
The Docker `events` package implements a composable event distribution package
for Go.
Originally created to implement the [notifications in Docker Registry
2](https://github.com/docker/distribution/blob/master/docs/notifications.md),
we've found the pattern to be useful in other applications. This package is
most of the same code with slightly updated interfaces. Much of the internals
have been made available.
## Usage
The `events` package centers around a `Sink` type. Events are written with
calls to `Sink.Write(event Event)`. Sinks can be wired up in various
configurations to achieve interesting behavior.
The canonical example is that employed by the
[docker/distribution/notifications](https://godoc.org/github.com/docker/distribution/notifications)
package. Let's say we have a type `httpSink` where we'd like to queue
notifications. As a rule, it should send a single http request and return an
error if it fails:
```go
func (h *httpSink) Write(event Event) error {
p, err := json.Marshal(event)
if err != nil {
return err
}
body := bytes.NewReader(p)
resp, err := h.client.Post(h.url, "application/json", body)
if err != nil {
return err
}
defer resp.Body.Close()
if resp.Status != 200 {
return errors.New("unexpected status")
}
return nil
}
// implement (*httpSink).Close()
```
With just that, we can start using components from this package. One can call
`(*httpSink).Write` to send events as the body of a post request to a
configured URL.
### Retries
HTTP can be unreliable. The first feature we'd like is to have some retry:
```go
hs := newHTTPSink(/*...*/)
retry := NewRetryingSink(hs, NewBreaker(5, time.Second))
```
We now have a sink that will retry events against the `httpSink` until they
succeed. The retry will backoff for one second after 5 consecutive failures
using the breaker strategy.
### Queues
This isn't quite enough. We we want a sink that doesn't block while we are
waiting for events to be sent. Let's add a `Queue`:
```go
queue := NewQueue(retry)
```
Now, we have an unbounded queue that will work through all events sent with
`(*Queue).Write`. Events can be added asynchronously to the queue without
blocking the current execution path. This is ideal for use in an http request.
### Broadcast
It usually turns out that you want to send to more than one listener. We can
use `Broadcaster` to support this:
```go
var broadcast = NewBroadcaster() // make it available somewhere in your application.
broadcast.Add(queue) // add your queue!
broadcast.Add(queue2) // and another!
```
With the above, we can now call `broadcast.Write` in our http handlers and have
all the events distributed to each queue. Because the events are queued, not
listener blocks another.
### Extending
For the most part, the above is sufficient for a lot of applications. However,
extending the above functionality can be done implementing your own `Sink`. The
behavior and semantics of the sink can be completely dependent on the
application requirements. The interface is provided below for reference:
```go
type Sink {
Write(Event) error
Close() error
}
```
Application behavior can be controlled by how `Write` behaves. The examples
above are designed to queue the message and return as quickly as possible.
Other implementations may block until the event is committed to durable
storage.
## Copyright and license
Copyright © 2016 Docker, Inc. go-events is licensed under the Apache License,
Version 2.0. See [LICENSE](LICENSE) for the full license text.

178
vendor/github.com/docker/go-events/broadcast.go generated vendored Normal file
View File

@ -0,0 +1,178 @@
package events
import (
"fmt"
"sync"
"github.com/sirupsen/logrus"
)
// Broadcaster sends events to multiple, reliable Sinks. The goal of this
// component is to dispatch events to configured endpoints. Reliability can be
// provided by wrapping incoming sinks.
type Broadcaster struct {
sinks []Sink
events chan Event
adds chan configureRequest
removes chan configureRequest
shutdown chan struct{}
closed chan struct{}
once sync.Once
}
// NewBroadcaster appends one or more sinks to the list of sinks. The
// broadcaster behavior will be affected by the properties of the sink.
// Generally, the sink should accept all messages and deal with reliability on
// its own. Use of EventQueue and RetryingSink should be used here.
func NewBroadcaster(sinks ...Sink) *Broadcaster {
b := Broadcaster{
sinks: sinks,
events: make(chan Event),
adds: make(chan configureRequest),
removes: make(chan configureRequest),
shutdown: make(chan struct{}),
closed: make(chan struct{}),
}
// Start the broadcaster
go b.run()
return &b
}
// Write accepts an event to be dispatched to all sinks. This method will never
// fail and should never block (hopefully!). The caller cedes the memory to the
// broadcaster and should not modify it after calling write.
func (b *Broadcaster) Write(event Event) error {
select {
case b.events <- event:
case <-b.closed:
return ErrSinkClosed
}
return nil
}
// Add the sink to the broadcaster.
//
// The provided sink must be comparable with equality. Typically, this just
// works with a regular pointer type.
func (b *Broadcaster) Add(sink Sink) error {
return b.configure(b.adds, sink)
}
// Remove the provided sink.
func (b *Broadcaster) Remove(sink Sink) error {
return b.configure(b.removes, sink)
}
type configureRequest struct {
sink Sink
response chan error
}
func (b *Broadcaster) configure(ch chan configureRequest, sink Sink) error {
response := make(chan error, 1)
for {
select {
case ch <- configureRequest{
sink: sink,
response: response}:
ch = nil
case err := <-response:
return err
case <-b.closed:
return ErrSinkClosed
}
}
}
// Close the broadcaster, ensuring that all messages are flushed to the
// underlying sink before returning.
func (b *Broadcaster) Close() error {
b.once.Do(func() {
close(b.shutdown)
})
<-b.closed
return nil
}
// run is the main broadcast loop, started when the broadcaster is created.
// Under normal conditions, it waits for events on the event channel. After
// Close is called, this goroutine will exit.
func (b *Broadcaster) run() {
defer close(b.closed)
remove := func(target Sink) {
for i, sink := range b.sinks {
if sink == target {
b.sinks = append(b.sinks[:i], b.sinks[i+1:]...)
break
}
}
}
for {
select {
case event := <-b.events:
for _, sink := range b.sinks {
if err := sink.Write(event); err != nil {
if err == ErrSinkClosed {
// remove closed sinks
remove(sink)
continue
}
logrus.WithField("event", event).WithField("events.sink", sink).WithError(err).
Errorf("broadcaster: dropping event")
}
}
case request := <-b.adds:
// while we have to iterate for add/remove, common iteration for
// send is faster against slice.
var found bool
for _, sink := range b.sinks {
if request.sink == sink {
found = true
break
}
}
if !found {
b.sinks = append(b.sinks, request.sink)
}
// b.sinks[request.sink] = struct{}{}
request.response <- nil
case request := <-b.removes:
remove(request.sink)
request.response <- nil
case <-b.shutdown:
// close all the underlying sinks
for _, sink := range b.sinks {
if err := sink.Close(); err != nil && err != ErrSinkClosed {
logrus.WithField("events.sink", sink).WithError(err).
Errorf("broadcaster: closing sink failed")
}
}
return
}
}
}
func (b *Broadcaster) String() string {
// Serialize copy of this broadcaster without the sync.Once, to avoid
// a data race.
b2 := map[string]interface{}{
"sinks": b.sinks,
"events": b.events,
"adds": b.adds,
"removes": b.removes,
"shutdown": b.shutdown,
"closed": b.closed,
}
return fmt.Sprint(b2)
}

61
vendor/github.com/docker/go-events/channel.go generated vendored Normal file
View File

@ -0,0 +1,61 @@
package events
import (
"fmt"
"sync"
)
// Channel provides a sink that can be listened on. The writer and channel
// listener must operate in separate goroutines.
//
// Consumers should listen on Channel.C until Closed is closed.
type Channel struct {
C chan Event
closed chan struct{}
once sync.Once
}
// NewChannel returns a channel. If buffer is zero, the channel is
// unbuffered.
func NewChannel(buffer int) *Channel {
return &Channel{
C: make(chan Event, buffer),
closed: make(chan struct{}),
}
}
// Done returns a channel that will always proceed once the sink is closed.
func (ch *Channel) Done() chan struct{} {
return ch.closed
}
// Write the event to the channel. Must be called in a separate goroutine from
// the listener.
func (ch *Channel) Write(event Event) error {
select {
case ch.C <- event:
return nil
case <-ch.closed:
return ErrSinkClosed
}
}
// Close the channel sink.
func (ch *Channel) Close() error {
ch.once.Do(func() {
close(ch.closed)
})
return nil
}
func (ch *Channel) String() string {
// Serialize a copy of the Channel that doesn't contain the sync.Once,
// to avoid a data race.
ch2 := map[string]interface{}{
"C": ch.C,
"closed": ch.closed,
}
return fmt.Sprint(ch2)
}

10
vendor/github.com/docker/go-events/errors.go generated vendored Normal file
View File

@ -0,0 +1,10 @@
package events
import "fmt"
var (
// ErrSinkClosed is returned if a write is issued to a sink that has been
// closed. If encountered, the error should be considered terminal and
// retries will not be successful.
ErrSinkClosed = fmt.Errorf("events: sink closed")
)

15
vendor/github.com/docker/go-events/event.go generated vendored Normal file
View File

@ -0,0 +1,15 @@
package events
// Event marks items that can be sent as events.
type Event interface{}
// Sink accepts and sends events.
type Sink interface {
// Write an event to the Sink. If no error is returned, the caller will
// assume that all events have been committed to the sink. If an error is
// received, the caller may retry sending the event.
Write(event Event) error
// Close the sink, possibly waiting for pending events to flush.
Close() error
}

52
vendor/github.com/docker/go-events/filter.go generated vendored Normal file
View File

@ -0,0 +1,52 @@
package events
// Matcher matches events.
type Matcher interface {
Match(event Event) bool
}
// MatcherFunc implements matcher with just a function.
type MatcherFunc func(event Event) bool
// Match calls the wrapped function.
func (fn MatcherFunc) Match(event Event) bool {
return fn(event)
}
// Filter provides an event sink that sends only events that are accepted by a
// Matcher. No methods on filter are goroutine safe.
type Filter struct {
dst Sink
matcher Matcher
closed bool
}
// NewFilter returns a new filter that will send to events to dst that return
// true for Matcher.
func NewFilter(dst Sink, matcher Matcher) Sink {
return &Filter{dst: dst, matcher: matcher}
}
// Write an event to the filter.
func (f *Filter) Write(event Event) error {
if f.closed {
return ErrSinkClosed
}
if f.matcher.Match(event) {
return f.dst.Write(event)
}
return nil
}
// Close the filter and allow no more events to pass through.
func (f *Filter) Close() error {
// TODO(stevvooe): Not all sinks should have Close.
if f.closed {
return nil
}
f.closed = true
return f.dst.Close()
}

111
vendor/github.com/docker/go-events/queue.go generated vendored Normal file
View File

@ -0,0 +1,111 @@
package events
import (
"container/list"
"sync"
"github.com/sirupsen/logrus"
)
// Queue accepts all messages into a queue for asynchronous consumption
// by a sink. It is unbounded and thread safe but the sink must be reliable or
// events will be dropped.
type Queue struct {
dst Sink
events *list.List
cond *sync.Cond
mu sync.Mutex
closed bool
}
// NewQueue returns a queue to the provided Sink dst.
func NewQueue(dst Sink) *Queue {
eq := Queue{
dst: dst,
events: list.New(),
}
eq.cond = sync.NewCond(&eq.mu)
go eq.run()
return &eq
}
// Write accepts the events into the queue, only failing if the queue has
// been closed.
func (eq *Queue) Write(event Event) error {
eq.mu.Lock()
defer eq.mu.Unlock()
if eq.closed {
return ErrSinkClosed
}
eq.events.PushBack(event)
eq.cond.Signal() // signal waiters
return nil
}
// Close shutsdown the event queue, flushing
func (eq *Queue) Close() error {
eq.mu.Lock()
defer eq.mu.Unlock()
if eq.closed {
return nil
}
// set closed flag
eq.closed = true
eq.cond.Signal() // signal flushes queue
eq.cond.Wait() // wait for signal from last flush
return eq.dst.Close()
}
// run is the main goroutine to flush events to the target sink.
func (eq *Queue) run() {
for {
event := eq.next()
if event == nil {
return // nil block means event queue is closed.
}
if err := eq.dst.Write(event); err != nil {
// TODO(aaronl): Dropping events could be bad depending
// on the application. We should have a way of
// communicating this condition. However, logging
// at a log level above debug may not be appropriate.
// Eventually, go-events should not use logrus at all,
// and should bubble up conditions like this through
// error values.
logrus.WithFields(logrus.Fields{
"event": event,
"sink": eq.dst,
}).WithError(err).Debug("eventqueue: dropped event")
}
}
}
// next encompasses the critical section of the run loop. When the queue is
// empty, it will block on the condition. If new data arrives, it will wake
// and return a block. When closed, a nil slice will be returned.
func (eq *Queue) next() Event {
eq.mu.Lock()
defer eq.mu.Unlock()
for eq.events.Len() < 1 {
if eq.closed {
eq.cond.Broadcast()
return nil
}
eq.cond.Wait()
}
front := eq.events.Front()
block := front.Value.(Event)
eq.events.Remove(front)
return block
}

260
vendor/github.com/docker/go-events/retry.go generated vendored Normal file
View File

@ -0,0 +1,260 @@
package events
import (
"fmt"
"math/rand"
"sync"
"sync/atomic"
"time"
"github.com/sirupsen/logrus"
)
// RetryingSink retries the write until success or an ErrSinkClosed is
// returned. Underlying sink must have p > 0 of succeeding or the sink will
// block. Retry is configured with a RetryStrategy. Concurrent calls to a
// retrying sink are serialized through the sink, meaning that if one is
// in-flight, another will not proceed.
type RetryingSink struct {
sink Sink
strategy RetryStrategy
closed chan struct{}
once sync.Once
}
// NewRetryingSink returns a sink that will retry writes to a sink, backing
// off on failure. Parameters threshold and backoff adjust the behavior of the
// circuit breaker.
func NewRetryingSink(sink Sink, strategy RetryStrategy) *RetryingSink {
rs := &RetryingSink{
sink: sink,
strategy: strategy,
closed: make(chan struct{}),
}
return rs
}
// Write attempts to flush the events to the downstream sink until it succeeds
// or the sink is closed.
func (rs *RetryingSink) Write(event Event) error {
logger := logrus.WithField("event", event)
retry:
select {
case <-rs.closed:
return ErrSinkClosed
default:
}
if backoff := rs.strategy.Proceed(event); backoff > 0 {
select {
case <-time.After(backoff):
// TODO(stevvooe): This branch holds up the next try. Before, we
// would simply break to the "retry" label and then possibly wait
// again. However, this requires all retry strategies to have a
// large probability of probing the sync for success, rather than
// just backing off and sending the request.
case <-rs.closed:
return ErrSinkClosed
}
}
if err := rs.sink.Write(event); err != nil {
if err == ErrSinkClosed {
// terminal!
return err
}
logger := logger.WithError(err) // shadow!!
if rs.strategy.Failure(event, err) {
logger.Errorf("retryingsink: dropped event")
return nil
}
logger.Errorf("retryingsink: error writing event, retrying")
goto retry
}
rs.strategy.Success(event)
return nil
}
// Close closes the sink and the underlying sink.
func (rs *RetryingSink) Close() error {
rs.once.Do(func() {
close(rs.closed)
})
return nil
}
func (rs *RetryingSink) String() string {
// Serialize a copy of the RetryingSink without the sync.Once, to avoid
// a data race.
rs2 := map[string]interface{}{
"sink": rs.sink,
"strategy": rs.strategy,
"closed": rs.closed,
}
return fmt.Sprint(rs2)
}
// RetryStrategy defines a strategy for retrying event sink writes.
//
// All methods should be goroutine safe.
type RetryStrategy interface {
// Proceed is called before every event send. If proceed returns a
// positive, non-zero integer, the retryer will back off by the provided
// duration.
//
// An event is provided, by may be ignored.
Proceed(event Event) time.Duration
// Failure reports a failure to the strategy. If this method returns true,
// the event should be dropped.
Failure(event Event, err error) bool
// Success should be called when an event is sent successfully.
Success(event Event)
}
// Breaker implements a circuit breaker retry strategy.
//
// The current implementation never drops events.
type Breaker struct {
threshold int
recent int
last time.Time
backoff time.Duration // time after which we retry after failure.
mu sync.Mutex
}
var _ RetryStrategy = &Breaker{}
// NewBreaker returns a breaker that will backoff after the threshold has been
// tripped. A Breaker is thread safe and may be shared by many goroutines.
func NewBreaker(threshold int, backoff time.Duration) *Breaker {
return &Breaker{
threshold: threshold,
backoff: backoff,
}
}
// Proceed checks the failures against the threshold.
func (b *Breaker) Proceed(event Event) time.Duration {
b.mu.Lock()
defer b.mu.Unlock()
if b.recent < b.threshold {
return 0
}
return b.last.Add(b.backoff).Sub(time.Now())
}
// Success resets the breaker.
func (b *Breaker) Success(event Event) {
b.mu.Lock()
defer b.mu.Unlock()
b.recent = 0
b.last = time.Time{}
}
// Failure records the failure and latest failure time.
func (b *Breaker) Failure(event Event, err error) bool {
b.mu.Lock()
defer b.mu.Unlock()
b.recent++
b.last = time.Now().UTC()
return false // never drop events.
}
var (
// DefaultExponentialBackoffConfig provides a default configuration for
// exponential backoff.
DefaultExponentialBackoffConfig = ExponentialBackoffConfig{
Base: time.Second,
Factor: time.Second,
Max: 20 * time.Second,
}
)
// ExponentialBackoffConfig configures backoff parameters.
//
// Note that these parameters operate on the upper bound for choosing a random
// value. For example, at Base=1s, a random value in [0,1s) will be chosen for
// the backoff value.
type ExponentialBackoffConfig struct {
// Base is the minimum bound for backing off after failure.
Base time.Duration
// Factor sets the amount of time by which the backoff grows with each
// failure.
Factor time.Duration
// Max is the absolute maxiumum bound for a single backoff.
Max time.Duration
}
// ExponentialBackoff implements random backoff with exponentially increasing
// bounds as the number consecutive failures increase.
type ExponentialBackoff struct {
failures uint64 // consecutive failure counter (needs to be 64-bit aligned)
config ExponentialBackoffConfig
}
// NewExponentialBackoff returns an exponential backoff strategy with the
// desired config. If config is nil, the default is returned.
func NewExponentialBackoff(config ExponentialBackoffConfig) *ExponentialBackoff {
return &ExponentialBackoff{
config: config,
}
}
// Proceed returns the next randomly bound exponential backoff time.
func (b *ExponentialBackoff) Proceed(event Event) time.Duration {
return b.backoff(atomic.LoadUint64(&b.failures))
}
// Success resets the failures counter.
func (b *ExponentialBackoff) Success(event Event) {
atomic.StoreUint64(&b.failures, 0)
}
// Failure increments the failure counter.
func (b *ExponentialBackoff) Failure(event Event, err error) bool {
atomic.AddUint64(&b.failures, 1)
return false
}
// backoff calculates the amount of time to wait based on the number of
// consecutive failures.
func (b *ExponentialBackoff) backoff(failures uint64) time.Duration {
if failures <= 0 {
// proceed normally when there are no failures.
return 0
}
factor := b.config.Factor
if factor <= 0 {
factor = DefaultExponentialBackoffConfig.Factor
}
backoff := b.config.Base + factor*time.Duration(1<<(failures-1))
max := b.config.Max
if max <= 0 {
max = DefaultExponentialBackoffConfig.Max
}
if backoff > max || backoff < 0 {
backoff = max
}
// Choose a uniformly distributed value from [0, backoff).
return time.Duration(rand.Int63n(int64(backoff)))
}

2
vendor/modules.txt vendored
View File

@ -61,6 +61,8 @@ github.com/denverdino/aliyungo/oss
github.com/denverdino/aliyungo/util
# github.com/dgrijalva/jwt-go v0.0.0-20170104182250-a601269ab70c
github.com/dgrijalva/jwt-go
# github.com/docker/go-events v0.0.0-20190806004212-e31b211e4f1c
github.com/docker/go-events
# github.com/docker/go-metrics v0.0.1
github.com/docker/go-metrics
# github.com/docker/libtrust v0.0.0-20150114040149-fa567046d9b1