func main() {
flag.Parse()
wl, err := whiplash.New(*whipconf, true)
if err != nil {
log.Fatalf("error reading configuration file: %v\n", err)
}
sigchan := whiplash.AppSetup("whiplash-client", "0.1.0", pclient.Pkgname, pclient.Version)
defer whiplash.AppCleanup("whiplash-client")
// need a pclient configuration to talk to the aggregator with
pcconf = &pclient.Config{
Addr: wl.Aggregator.BindAddr + ":" + wl.Aggregator.BindPort,
Timeout: wl.Client.Timeout,
}
// decide what notification interval to use
rand.Seed(time.Now().UnixNano())
intv = rand.Intn(len(intvs))
log.Printf("using interval set: %q\n", intvs[intv])
// create tickers and launch monitor funcs
pingticker := time.NewTicker(time.Second * intvs[intv]["ping"])
statticker := time.NewTicker(time.Second * intvs[intv]["stat"])
go pingSvcs(wl.Svcs, pingticker.C)
go statSvcs(wl.Svcs, statticker.C)
// mainloop
keepalive := true
for keepalive {
select {
case <-sigchan:
// we've trapped a signal from the OS. tell our Asock to
// shut down, but don't exit the eventloop because we want
// to handle the Msgs which will be incoming.
log.Println("OS signal received; shutting down")
keepalive = false
}
// there's no default case in the select, as that would cause
// it to be nonblocking. and that would cause main() to exit
// immediately.
}
}
func main() {
// parse flags
flag.Parse()
// read the whiplash configuration
wl, err := whiplash.New(*whipconf, false)
if err != nil {
log.Fatalf("error reading configuration file: %v\n", err)
}
// and do application initialization
sigchan := whiplash.AppSetup("whiplash-aggregator", "0.1.1", petrel.Pkgname, petrel.Version)
defer whiplash.AppCleanup("whiplash-aggregator")
// setup the client petrel instance. first set the msglvl, then
// instantiate the petrel.
phconf := &petrel.Config{
Sockname: wl.Aggregator.BindAddr + ":" + wl.Aggregator.BindPort,
Msglvl: msglvl[wl.Aggregator.MsgLvl],
Timeout: wl.Aggregator.Timeout,
}
cph, err := petrel.NewTCP(phconf)
if err != nil {
log.Fatal(err)
}
// and add command handlers to the petrel instance
handlers := map[string]petrel.DispatchFunc{
"ping": pingHandler,
"stat": statHandler,
}
for name, handler := range handlers {
err = cph.AddFunc(name, "nosplit", handler)
if err != nil {
log.Fatal(err)
}
}
log.Println("client petrel instantiated")
// now setup the query petrel instance
phconf = &petrel.Config{
Sockname: wl.Aggregator.BindAddr + ":" + wl.Aggregator.QueryPort,
Msglvl: msglvl[wl.Aggregator.MsgLvl],
Timeout: wl.Aggregator.QTimeout,
}
qph, err := petrel.NewTCP(phconf)
if err != nil {
log.Fatal(err)
}
// add command handlers to the query petrel instance
handlers = map[string]petrel.DispatchFunc{
"echo": qhEcho,
}
for name, handler := range handlers {
err = qph.AddFunc(name, "split", handler)
if err != nil {
log.Fatal(err)
}
}
log.Println("query petrel instantiated")
// create a channel for the client petrel Msgr handler
msgchan := make(chan error, 1)
// and one for the query Msgr handler
querychan := make(chan error, 1)
// and launch them
go msgHandler(cph, msgchan)
go msgHandler(qph, querychan)
log.Println("aggregator now listening")
// this is the mainloop of the application.
keepalive := true
for keepalive {
select {
case msg := <-msgchan:
// we've been handed a Msg over msgchan, which means that
// our Handler has shut itself down for some reason. if this
// were a more robust server, we would modularize Handler
// creation and this eventloop, so that should we trap a
// 599 we could spawn a new Handler and launch it in this
// one's place. but we're just gonna exit this loop,
// causing main() to terminate, and with it the server
// instance.
log.Println("Handler has shut down. Last Msg received was:")
log.Println(msg)
keepalive = false
break
case msg := <-querychan:
// the query handler has died. it should be safe to
// restart.
log.Println("Query handler has shut down. Last Msg received was:")
log.Println(msg)
log.Println("Restarting query petrel...")
// TODO what it says ^^there
case <-sigchan:
// we've trapped a signal from the OS. tell our Petrel to
// shut down, but don't exit the eventloop because we want
// to handle the Msgs which will be incoming.
log.Println("OS signal received; shutting down")
cph.Quit()
}
// there's no default case in the select, as that would cause
// it to be nonblocking. and that would cause main() to exit
// immediately.
}
}