harness-drone/handler/api/events/build.go
2019-02-19 15:56:41 -08:00

105 lines
2.4 KiB
Go

// Copyright 2019 Drone.IO Inc. All rights reserved.
// Use of this source code is governed by the Drone Non-Commercial License
// that can be found in the LICENSE file.
package events
import (
"context"
"io"
"net/http"
"time"
"github.com/drone/drone/handler/api/render"
"github.com/drone/drone/logger"
"github.com/drone/drone/core"
"github.com/sirupsen/logrus"
"github.com/go-chi/chi"
)
// interval at which the client is pinged to prevent
// reverse proxy and load balancers from closing the
// connection.
var pingInterval = time.Second * 30
// implements a 24-hour timeout for connections. This
// should not be necessary, but is put in place just
// in case we encounter dangling connections.
var timeout = time.Hour * 24
// HandleEvents creates an http.HandlerFunc that streams builds events
// to the http.Response in an event stream format.
func HandleEvents(
repos core.RepositoryStore,
events core.Pubsub,
) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
var (
namespace = chi.URLParam(r, "owner")
name = chi.URLParam(r, "name")
)
logger := logger.FromRequest(r).WithFields(
logrus.Fields{
"namespace": namespace,
"name": name,
},
)
repo, err := repos.FindName(r.Context(), namespace, name)
if err != nil {
render.NotFound(w, err)
logger.WithError(err).Debugln("events: cannot find repository")
return
}
h := w.Header()
h.Set("Content-Type", "text/event-stream")
h.Set("Cache-Control", "no-cache")
h.Set("Connection", "keep-alive")
h.Set("X-Accel-Buffering", "no")
f, ok := w.(http.Flusher)
if !ok {
return
}
io.WriteString(w, ": ping\n\n")
f.Flush()
ctx, cancel := context.WithCancel(r.Context())
defer cancel()
events, errc := events.Subscribe(ctx)
logger.Debugln("events: stream opened")
L:
for {
select {
case <-ctx.Done():
logger.Debugln("events: stream cancelled")
break L
case <-errc:
logger.Debugln("events: stream error")
break L
case <-time.After(time.Hour):
logger.Debugln("events: stream timeout")
break L
case <-time.After(pingInterval):
io.WriteString(w, ": ping\n\n")
f.Flush()
case event := <-events:
if event.Repository == repo.Slug {
io.WriteString(w, "data: ")
w.Write(event.Data)
io.WriteString(w, "\n\n")
f.Flush()
}
}
}
io.WriteString(w, "event: error\ndata: eof\n\n")
f.Flush()
logger.Debugln("events: stream closed")
}
}