//process recreates the request that should be sent to the target host
//it stores the response in the store of replies.
func (c *Consumer) process(petition *Petition) {
var (
req *http.Request
resp *http.Response
reply *Reply
start = bson.Now()
)
db := c.SessionSeed.DB(c.Cfg.Database)
petColl := db.C(c.Cfg.Instance + c.Cfg.PetitionsColl)
replyColl := db.C(c.Cfg.ResponsesColl)
errColl := db.C(c.Cfg.ErrorsColl)
mylog.Debugf("processing petition %+v", petition)
req, err := petition.Request()
if err != nil {
mylog.Alert(petition.ID, err)
return
}
mylog.Debugf("restored request %+v", req)
mylog.Debug("before making request", petition.ID)
resp, err = c.doRequest(req, petition.ID)
if err == nil {
mylog.Debug("after making request", petition.ID)
defer func() {
mylog.Debug("closing response body", petition.ID)
resp.Body.Close()
}()
}
reply = newReply(resp, petition, err)
reply.Created = start
mylog.Debugf("created reply %+v", reply)
if err != nil || resp.StatusCode < 200 || resp.StatusCode >= 300 {
e := errColl.Insert(reply)
if e != nil {
mylog.Alert("ERROR inserting erroneous reply", petition.ID, err)
c.SessionSeed.Refresh()
}
}
mylog.Debugf("before insert reply %+v", reply)
err = replyColl.Insert(reply)
mylog.Debugf("after insert reply %+v", reply)
if err != nil {
mylog.Alert("ERROR inserting reply", petition.ID, err)
c.SessionSeed.Refresh()
}
mylog.Debugf("before remove petition %+v", petition)
err = petColl.Remove(bson.M{"id": petition.ID})
mylog.Debugf("after remove petition %+v", petition)
if err != nil {
mylog.Alert("ERROR removing petition", petition.ID, err)
c.SessionSeed.Refresh()
}
}
//ServeHTTP implements HTTP handler interface
func (l *Listener) ServeHTTP(w http.ResponseWriter, r *http.Request) {
mylog.Debugf("received request %+v", r)
w.Header().Set("Content-Type", "application/json")
if l.Stopped() {
mylog.Debug("warning client server is stopping")
http.Error(w, `{"error":"Server is shutting down"}`, 503)
return
}
relayedRequest, e := newPetition(r)
if e != nil {
mylog.Debug("petition with error", e)
http.Error(w, fmt.Sprintf(`{"error": %q }`, e), 400)
return
}
db := l.SessionSeed.DB(l.Cfg.Database)
petColl := db.C(l.Cfg.Instance + l.Cfg.PetitionsColl)
mylog.Debugf("petition created %+v", relayedRequest)
e = petColl.Insert(relayedRequest)
if e != nil {
http.Error(w, fmt.Sprintf(`{"error": %q, "ref":%q }`, e, relayedRequest.ID), 500)
mylog.Alert("ERROR inserting", relayedRequest.ID, e)
l.SessionSeed.Refresh()
return
}
select {
case l.SendTo <- relayedRequest:
mylog.Debug("enqueued petition", relayedRequest)
fmt.Fprintf(w, "{\"id\":%q}\n", relayedRequest.ID)
default:
mylog.Alert("server is busy")
http.Error(w, `{"error":"Server is busy"}`, 500)
mylog.Debugf("before remove petition", relayedRequest.ID)
err := petColl.Remove(bson.M{"id": relayedRequest.ID})
mylog.Debugf("after remove petition", relayedRequest.ID)
if err != nil {
mylog.Alert("ERROR removing petition", relayedRequest.ID, e)
l.SessionSeed.Refresh()
return
}
return
}
}
func main() {
var cfgFile = flag.String("config", "./gridas.yaml", "configuration file")
flag.Parse()
cfg, err := config.ReadConfig(*cfgFile)
if err != nil {
mylog.Alert(err)
os.Exit(-1)
}
fmt.Printf("configuration %q %+v\n", *cfgFile, cfg)
mylog.SetLevel(cfg.LogLevel)
mylog.Alert("hello World!")
reqChan := make(chan *gridas.Petition, cfg.QueueSize)
session, err := mgo.Dial(cfg.Mongo)
if err != nil {
mylog.Alert(err)
panic(err)
}
defer func() {
session.Close()
mylog.Debugf("mongo session closed %+v", session)
}()
mylog.Debugf("mongo session %+v", session)
db := session.DB(cfg.Database)
mylog.Debug("mongo database", db)
listener := &gridas.Listener{SendTo: reqChan, Cfg: cfg, SessionSeed: session}
mylog.Debugf("listener %+v", listener)
consumer := &gridas.Consumer{GetFrom: reqChan, Cfg: cfg, SessionSeed: session}
mylog.Debugf("consumer %+v", consumer)
rplyr := &gridas.Replyer{Cfg: cfg, SessionSeed: session}
mylog.Debugf("replyer %+v", rplyr)
rcvr := &gridas.Recoverer{SendTo: reqChan, Cfg: cfg, SessionSeed: session}
mylog.Debugf("recoverer %+v", rcvr)
endConsumers := consumer.Start(cfg.Consumers)
if err := rcvr.Recover(); err != nil {
mylog.Alert(err)
os.Exit(-1)
}
http.Handle("/", listener)
http.Handle("/responses/", http.StripPrefix("/responses/", rplyr))
go func() {
mylog.Debug("starting HTTP server (listener)")
err := http.ListenAndServe(":"+cfg.Port, nil)
if err != nil {
mylog.Alert(err)
os.Exit(-1)
}
}()
onEnd(func() {
mylog.Info("shutting down gridas ...")
listener.Stop()
mylog.Debug("listener stopped")
consumer.Stop()
mylog.Debug("consumer stopped")
})
<-endConsumers
mylog.Alert("bye World!")
}