// Connect - Will connect and ping connection in hope that all is ok
func (m *Connection) Connect() error {
m.Logger.Debug("Connecting to MySQL server (uri: %s) ...", m.URI)
var err error
m.DB, err = gorm.Open("mysql", m.URI)
//m.DB.SetLogger(m.Logger)
if err != nil {
m.Logger.Error("Got error while attempting to create mysql connection: %s", err)
return err
}
if err := m.DB.DB().Ping(); err != nil {
m.Logger.Error("Got error while attempting to PING database: %s", err)
return err
}
concurrency := utils.GetConcurrencyCount("PU_GO_MAX_CONCURRENCY")
// Setting up max idle conns based on concurrency
m.DB.DB().SetMaxIdleConns(int(concurrency))
m.DB.DB().SetMaxOpenConns(int(concurrency))
return nil
}
// Start -
func (c *Connection) Start(done chan bool) error {
opts := MQTT.NewClientOptions().AddBroker(c.GetBrokerAddr())
opts.SetClientID(c.GetBrokerClientID())
opts.SetDefaultPublishHandler(c.BrokerHandler)
opts.SetAutoReconnect(true)
username, password := c.GetBrokerCredentials()
opts.SetUsername(username)
opts.SetPassword(password)
concurrency := utils.GetConcurrencyCount("PU_GO_MAX_CONCURRENCY")
c.events = make(chan events.Event, concurrency)
errors := make(chan error)
connected := make(chan bool)
go func() {
for {
c.Info("Starting MQTT (connection: %s) on (addr: %s)...", c.Name(), c.GetBrokerAddr())
reload := make(chan bool)
c.conn = MQTT.NewClient(opts)
if token := c.conn.Connect(); token.Wait() && token.Error() != nil {
errors <- fmt.Errorf("Failed to establish connection with mqtt server (error: %s)", token.Error())
continue
}
if !c.conn.IsConnected() {
continue
}
c.Subscribe(c.GetBrokerTopicName(), MaxTopicSubscribeAttempts)
// Notify rest of the app that we're ready ...
close(connected)
go func() {
cct := time.Tick(2 * time.Second)
for {
select {
case <-cct:
if !c.conn.IsConnected() {
reload <- true
return
}
case <-done:
c.Warning("Received stop signal for mqtt (worker: %s). Will not attempt to restart worker ...", c.Name())
return
}
}
}()
reloadloop:
for {
select {
case <-reload:
c.Warning("Mqtt (worker: %s) seems not to be connected. Restarting loop in 2 seconds ...", c.Name())
time.Sleep(2 * time.Second)
break reloadloop
}
}
}
}()
select {
case <-connected:
c.Info(
"Successfully established mqtt connection for (worker: %s) on (addr: %s)",
c.Name(), c.GetBrokerAddr(),
)
break
// @TODO - Figure out how to handle multiple errors ...
case err := <-errors:
return err
case <-time.After(time.Duration(InitialConnectionTimeout) * time.Second):
errors <- fmt.Errorf(
"Could not establish mqtt connection for (worker: %s) on (addr: %s) due to initial connection (timeout: %ds)",
c.Name(), c.GetBrokerAddr(), InitialConnectionTimeout,
)
break
}
return nil
}
