// Starts listening for client connections.
// When a new application connects, launches listeners in a goroutine.
// Returns an error when error occurs.
func StartListen(port int, useTls bool, crtPath string, keyPath string, sname string) error {
// Create a listening address
addr, err := net.ResolveTCPAddr("tcp", fmt.Sprintf(":%d", port))
if err != nil {
return err
}
// start a new server and listen on the address
var l net.Listener
l, err = net.ListenTCP("tcp", addr)
if err != nil {
return err
}
// wrap with TLS if required
if useTls {
cert, err := tls.LoadX509KeyPair(crtPath, keyPath)
if err != nil {
return err
}
conf := tls.Config{}
certs := make([]tls.Certificate, 1)
certs[0] = cert
conf.Certificates = certs
cp := x509.NewCertPool()
caCert, err := ioutil.ReadFile(crtPath)
if err != nil {
return err
}
if !cp.AppendCertsFromPEM(caCert) {
return errors.New("Could not append PEM cert")
}
conf.RootCAs = cp
conf.ServerName = sname
conf.ClientAuth = tls.RequireAndVerifyClientCert
conf.ClientCAs = cp
l = tls.NewListener(l, &conf)
}
// at the end of this function close the server connection
defer l.Close()
logging.Debug("Starting listen loop")
for {
a, err := acceptApp(l)
if err != nil {
return err
} else {
logging.Debug("Got connection")
go ListenForCommands(a)
}
}
return nil
}
func (c *commandStrategy) msgQuerySuccess() error {
c.app.RWMutex.RLock()
defer c.app.RWMutex.RUnlock()
logging.Debug("Replying to message from app %s", c.app.Manifest.InstanceId)
var id string
if id_, ok := getString(c.body, "id"); ok {
id = id_
} else {
return errors.New("No id found")
}
ret := c.body["ret"]
body := make(jsonData)
body["fromInstanceId"] = c.app.Manifest.InstanceId
body["id"] = id
body["ret"] = ret
if recipient, ok := msg_archive.GetMsg(id); ok {
recipient.Send("MSG_QUERY_SUCCESS", body)
} else {
logging.Warning("unrecognized message query id %s from app %s",
id,
c.app.Manifest.InstanceId)
}
return nil
}
func (c *commandStrategy) msgQueryFail() error {
c.app.RWMutex.RLock()
defer c.app.RWMutex.RUnlock()
logging.Debug("Sending message query fail from %s", c.app.Manifest.InstanceId)
var id, message string
if id_, ok := getString(c.body, "id"); ok {
id = id_
} else {
return errors.New("No id found")
}
if message_, ok := getString(c.body, "message"); !ok {
message = message_
} else {
return errors.New("No message found")
}
body := make(jsonData)
body["fromInstanceId"] = c.app.Manifest.InstanceId
body["id"] = id
body["message"] = message
if recipient, ok := msg_archive.GetMsg(id); ok {
recipient.Send("MSG_QUERY_FAIL", body)
} else {
logging.Warning("unrecognized message query id %s from app %s",
id,
c.app.Manifest.InstanceId)
}
return nil
}
func (c *commandStrategy) msgBroadcast() error {
c.app.RWMutex.RLock()
defer c.app.RWMutex.RUnlock()
var id string
content := c.body["content"]
logging.Debug("Sending message broadcast from %s", c.app.Manifest.InstanceId)
if id_, ok := getString(c.body, "id"); ok {
id = id_
} else {
return errors.New("No id found")
}
msg_archive.RecordMsg(c.app, id)
toSend := make(jsonData)
toSend["fromInstanceId"] = c.app.Manifest.InstanceId
toSend["id"] = id
toSend["content"] = content
for _, cpb := range c.app.Manifest.Capabilities {
for _, dep := range registry.GetDependents(cpb) {
dep.Send("MSG_BROADCAST", toSend)
}
}
return nil
}
// Parses a command given the command's message string
// (verb and body, no message length)
func ParseCommand(a *app.App, message string) (CommandStrategy, bool) {
id := "NO_ID_FOUND"
if a.Manifest != nil {
id = a.Manifest.InstanceId
}
logging.Debug("Parsing from app %s: \n%s", id, message)
ret, err := internalParseCommand(a, message)
if err != nil {
logging.Error("Parse failed from app %s: %s", id, err.Error())
return newFailedCommandStrategy(a, message, err.Error()), false
}
return ret, true
}
func (a *App) Send(verb string, body map[string]interface{}) error {
id := "NO_ID_FOUND"
if a.Manifest != nil {
id = a.Manifest.InstanceId
}
logging.Debug("Sending message %s to instance %s", verb, id)
verb += " "
bodyBytes, err := json.Marshal(body)
if err != nil {
return err
}
toSend := append([]byte(verb), bodyBytes...)
length := fmt.Sprintf("%d\n", len(toSend))
toSend = append([]byte(length), toSend...)
_, err = a.Connection.Write(toSend)
return err
}
// construct the app based on its manifest
func (c *commandStrategy) appManifest() bool {
c.app.RWMutex.Lock()
defer c.app.RWMutex.Unlock()
logging.Debug("Parsing application's manifest")
man, err := decodeManifest(c.body)
if err != nil {
logging.Error("App's manifest is invalid: %s", err)
sendManifestFail(c.app, err.Error())
return false
}
if _, exists := registry.GetInstance(man.InstanceId); exists {
logging.Error("App's instance id is already taken: %s", man.InstanceId)
sendManifestFail(c.app, fmt.Sprintf("instanceId %s is in use", man.InstanceId))
return false
}
c.app.Status = app.STATUS_DOWN
c.app.Manifest = man
registry.Register(c.app)
sendManifestOkAndDependencies(c.app)
logging.Info("App '%s' now connected with manifest parsed", c.app.Manifest.InstanceId)
return true
}
// send this message query to all targeted apps
func (c *commandStrategy) msgQuery() error {
c.app.RWMutex.RLock()
defer c.app.RWMutex.RUnlock()
logging.Debug("Processing query from %s", c.app.Manifest.InstanceId)
mq, err := parseMsgQuery(c)
if err != nil {
return err
}
msg_archive.RecordMsg(c.app, mq.id)
body := make(jsonData)
body["fromInstanceId"] = c.app.Manifest.InstanceId
body["id"] = mq.id
body["priority"] = mq.priority
body["data"] = mq.data
body["instanceId"] = mq.instanceIds
body["action"] = mq.action
body["capability"] = mq.capability.Name
// if this is an undirected query
if len(mq.instanceIds) == 0 {
// send to all providers of the capability
for _, provider := range registry.GetProviders(mq.capability) {
provider.Send("MSG_QUERY", body)
}
} else {
// this is a directed query, send to all given instance ids
for _, instName := range mq.instanceIds {
if inst, ok := registry.GetInstance(instName); ok {
inst.Send("MSG_QUERY", body)
}
}
}
return nil
}
