distribution/storage/notifications/http_test.go
Stephen J Day 9f0c8d6616 Implement notification endpoint webhook dispatch
This changeset implements webhook notification endpoints for dispatching
registry events. Repository instances can be decorated by a listener that
converts calls into context-aware events, using a bridge. Events generated in
the bridge are written to a sink. Implementations of sink include a broadcast
and endpoint sink which can be used to configure event dispatch. Endpoints
represent a webhook notification target, with queueing and retries built in.
They can be added to a Broadcaster, which is a simple sink that writes a block
of events to several sinks, to provide a complete dispatch mechanism.

The main caveat to the current approach is that all unsent notifications are
inmemory. Best effort is made to ensure that notifications are not dropped, to
the point where queues may back up on faulty endpoints. If the endpoint is
fixed, the events will be retried and all messages will go through.

Internally, this functionality is all made up of Sink objects. The queuing
functionality is implemented with an eventQueue sink and retries are
implemented with retryingSink. Replacing the inmemory queuing with something
persistent should be as simple as replacing broadcaster with a remote queue and
that sets up the sinks to be local workers listening to that remote queue.

Metrics are kept for each endpoint and exported via expvar. This may not be a
permanent appraoch but should provide enough information for troubleshooting
notification problems.

Signed-off-by: Stephen J Day <stephen.day@docker.com>
2015-02-03 13:30:20 -08:00

156 lines
3.8 KiB
Go

package notifications
import (
"encoding/json"
"fmt"
"mime"
"net/http"
"net/http/httptest"
"reflect"
"strconv"
"testing"
)
// TestHTTPSink mocks out an http endpoint and notifies it under a couple of
// conditions, ensuring correct behavior.
func TestHTTPSink(t *testing.T) {
server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
defer r.Body.Close()
if r.Method != "POST" {
w.WriteHeader(http.StatusMethodNotAllowed)
t.Fatalf("unexpected request method: %v", r.Method)
return
}
// Extract the content type and make sure it matches
contentType := r.Header.Get("Content-Type")
mediaType, _, err := mime.ParseMediaType(contentType)
if err != nil {
w.WriteHeader(http.StatusBadRequest)
t.Fatalf("error parsing media type: %v, contenttype=%q", err, contentType)
return
}
if mediaType != EventsMediaType {
w.WriteHeader(http.StatusUnsupportedMediaType)
t.Fatalf("incorrect media type: %q != %q", mediaType, EventsMediaType)
return
}
var envelope Envelope
dec := json.NewDecoder(r.Body)
if err := dec.Decode(&envelope); err != nil {
w.WriteHeader(http.StatusBadRequest)
t.Fatalf("error decoding request body: %v", err)
return
}
// Let caller choose the status
status, err := strconv.Atoi(r.FormValue("status"))
if err != nil {
t.Logf("error parsing status: %v", err)
// May just be empty, set status to 200
status = http.StatusOK
}
w.WriteHeader(status)
}))
metrics := newSafeMetrics()
sink := newHTTPSink(server.URL, 0, nil,
&endpointMetricsHTTPStatusListener{safeMetrics: metrics})
var expectedMetrics EndpointMetrics
expectedMetrics.Statuses = make(map[string]int)
for _, tc := range []struct {
events []Event // events to send
url string
failure bool // true if there should be a failure.
statusCode int // if not set, no status code should be incremented.
}{
{
statusCode: http.StatusOK,
events: []Event{
createTestEvent("push", "library/test", "manifest")},
},
{
statusCode: http.StatusOK,
events: []Event{
createTestEvent("push", "library/test", "manifest"),
createTestEvent("push", "library/test", "layer"),
createTestEvent("push", "library/test", "layer"),
},
},
{
statusCode: http.StatusTemporaryRedirect,
},
{
statusCode: http.StatusBadRequest,
failure: true,
},
{
// Case where connection never goes through.
url: "http://shoudlntresolve/",
failure: true,
},
} {
if tc.failure {
expectedMetrics.Failures += len(tc.events)
} else {
expectedMetrics.Successes += len(tc.events)
}
if tc.statusCode > 0 {
expectedMetrics.Statuses[fmt.Sprintf("%d %s", tc.statusCode, http.StatusText(tc.statusCode))] += len(tc.events)
}
url := tc.url
if url == "" {
url = server.URL + "/"
}
// setup endpoint to respond with expected status code.
url += fmt.Sprintf("?status=%v", tc.statusCode)
sink.url = url
t.Logf("testcase: %v, fail=%v", url, tc.failure)
// Try a simple event emission.
err := sink.Write(tc.events...)
if !tc.failure {
if err != nil {
t.Fatalf("unexpected error send event: %v", err)
}
} else {
if err == nil {
t.Fatalf("the endpoint should have rejected the request")
}
}
if !reflect.DeepEqual(metrics.EndpointMetrics, expectedMetrics) {
t.Fatalf("metrics not as expected: %#v != %#v", metrics.EndpointMetrics, expectedMetrics)
}
}
if err := sink.Close(); err != nil {
t.Fatalf("unexpected error closing http sink: %v", err)
}
// double close returns error
if err := sink.Close(); err == nil {
t.Fatalf("second close should have returned error: %v", err)
}
}
func createTestEvent(action, repo, typ string) Event {
event := createEvent(action)
event.Target.Type = typ
event.Target.Name = repo
return *event
}