static void Main(string[] args)
{
Timer tokenRenewalTimer = null;
var signalEvent = new ManualResetEvent(false);
var signalHandler = new UnixSignalHandler {
Logger = Logger
};
try
{
Logger.Info("LightNotificationClient starting...");
// intercept Unix signals (ie. CTRL-C) so we can shut down gracefully
signalHandler.HandleSignal(signal =>
{
Logger.Info("Signal received: " + signal);
signalEvent.Set();
});
// connect to pin 11
InitBoardGpio();
// get the initial daylight state and turn the light on or off accordingly
Logger.Info("Getting initial light state...");
RetryUntilSuccess(() =>
{
var lightState = (IsDaylight() ? Light.Off : Light.On);
Logger.Info("Setting light to " + lightState.ToString().ToLower());
ToggleLightSwitch(lightState);
}, numRetries: 10, delayBetweenRetriesMs: 5000);
// get service bus settings
var serviceBusNamespace = ConfigurationManager.AppSettings["ServiceBusNamespace"];
var sasKeyName = ConfigurationManager.AppSettings["SasKeyName"];
var sasKey = ConfigurationManager.AppSettings["SasKey"];
var topicName = ConfigurationManager.AppSettings["TopicName"];
var subscriptionName = Dns.GetHostName();
var topicAddress = string.Format("https://{0}.servicebus.windows.net/{1}", serviceBusNamespace, topicName);
var subscriptionAddress = string.Format("{0}/Subscriptions/{1}", topicAddress, subscriptionName);
// create service bus http client with SAS credentials good for 60 minutes
HttpClientHelper.DisableServerCertificateValidation = true;
var httpClientHelper = new HttpClientHelper(
serviceBusNamespace, sasKeyName, sasKey, AuthTokenExpirationMinutes)
{
Logger = Logger
};
// setup SAS token auto-renewal timer
tokenRenewalTimer = new Timer(x =>
{
httpClientHelper.RenewSasToken(AuthTokenExpirationMinutes);
Logger.Info("SAS token renewed");
}, null, RenewalInterval, RenewalInterval);
// verify the topic exists
Logger.Info("Querying service bus topic \"{0}\"...", topicName);
RetryUntilSuccess(() =>
{
var queryTopicResponse = httpClientHelper.GetEntity(topicAddress).Result;
var content = Encoding.UTF8.GetString(queryTopicResponse);
if (!content.Contains("TopicDescription"))
{
throw new Exception(string.Format("Service bus topic \"{0}\" does not exist.", topicName));
}
}, (exception) =>
{ // anonymous function to handle 401 unauthorized error, manually kick off the SAS renewal
if (exception is UnauthorizedAccessException)
{
HandleUnauthorizedAccessException(httpClientHelper, tokenRenewalTimer);
}
});
// get subscription configuration
var subscriptionDescriptionPath = Path.Combine(Path.GetDirectoryName(
Assembly.GetExecutingAssembly().Location), "SubscriptionDescription.xml");
var subscriptionDescription = Encoding.UTF8.GetBytes(File.ReadAllText(subscriptionDescriptionPath));
// create subscription
Logger.Info("Registering subscription \"{0}\"...", subscriptionName);
RetryUntilSuccess(() => httpClientHelper.CreateEntity(subscriptionAddress, subscriptionDescription).Wait(),
(exception) =>
{ // anonymous function to handle 401 unauthorized error, manually kick off the SAS renewal
if (exception is UnauthorizedAccessException)
{
HandleUnauthorizedAccessException(httpClientHelper, tokenRenewalTimer);
}
});
// delete current subscription rule
Logger.Info("Deleting current subscription rule...");
RetryUntilSuccess(() => httpClientHelper.DeleteEntity(subscriptionAddress + "/Rules/RecipientFilter").Wait(),
(exception) =>
{ // anonymous function to handle 401 unauthorized error, manually kick off the SAS renewal
if (exception is UnauthorizedAccessException)
{
HandleUnauthorizedAccessException(httpClientHelper, tokenRenewalTimer);
}
});
// create rule configuration
var ruleDescriptionPath = Path.Combine(Path.GetDirectoryName(
Assembly.GetExecutingAssembly().Location), "RuleDescription.xml");
var filterQuery = string.Format("RecipientId = '*' OR RecipientId = '{0}'", Dns.GetHostName().ToLower());
var ruleDescription = Encoding.UTF8.GetBytes(string.Format(File.ReadAllText(ruleDescriptionPath), filterQuery));
// create subscription rule
Logger.Info("Creating subscription rule...");
RetryUntilSuccess(() => httpClientHelper.CreateEntity(subscriptionAddress + "/Rules/RecipientFilter", ruleDescription).Wait(),
(exception) =>
{ // anonymous function to handle 401 unauthorized error, manually kick off the SAS renewal
if (exception is UnauthorizedAccessException)
{
HandleUnauthorizedAccessException(httpClientHelper, tokenRenewalTimer);
}
});
// now delete default subscription rule
Logger.Info("Deleting default subscription rule...");
RetryUntilSuccess(() => httpClientHelper.DeleteEntity(subscriptionAddress + "/Rules/$Default").Wait(),
(exception) =>
{ // anonymous function to handle 401 unauthorized error, manually kick off the SAS renewal
if (exception is UnauthorizedAccessException)
{
HandleUnauthorizedAccessException(httpClientHelper, tokenRenewalTimer);
}
});
var consecutiveErrors = 0;
Exception lastError = null;
Logger.Info("Waiting for messages...");
// start the message receiver loop
while (!signalEvent.WaitOne(TimeSpan.Zero))
{
try
{
#if DEBUG
const int timeoutInSeconds = 5;
#else
const int timeoutInSeconds = 60;
#endif
// Receive and delete message from the subscription.
var message = httpClientHelper.ReceiveAndDeleteMessage(subscriptionAddress, timeoutInSeconds).Result;
if (message != null)
{
Logger.Info("Received message: " + message.BrokerProperties.MessageId);
var light = (Light)Enum.Parse(typeof(Light), message.CustomProperties["LightState"]);
Logger.Info("Turning light " + light.ToString().ToLower());
ToggleLightSwitch(light);
}
consecutiveErrors = 0;
}
catch (AggregateException ae)
{
foreach (var ex in ae.InnerExceptions)
{
if (ex is UnauthorizedAccessException)
{
HandleUnauthorizedAccessException(httpClientHelper, tokenRenewalTimer);
}
else
{
Logger.Error(ex.Message);
}
lastError = ex;
}
Thread.Sleep(1000);
consecutiveErrors++;
}
catch (Exception ex)
{
Logger.Error(ex.Message);
lastError = ex;
Thread.Sleep(1000);
consecutiveErrors++;
}
if (consecutiveErrors >= 100)
{
throw new Exception("Unrecoverable error, giving up", lastError); // something REALLY wrong, abort mission
}
if (consecutiveErrors >= 10)
{
Thread.Sleep(TimeSpan.FromMinutes(1)); // something wrong here (network issues?), let's throttle down
}
}
}
catch (Exception ex)
{
Logger.Error("Fatal error: " + ex.Message);
var errorMessage = ex.Message;
if (ex.InnerException != null)
{
errorMessage += string.Format(": {0}", ex.InnerException.Message);
}
SendErrorMessage(errorMessage);
}
finally
{
if (tokenRenewalTimer != null)
{
tokenRenewalTimer.Dispose();
}
if (_gpio != null)
{
_gpio.Close();
}
signalHandler.Dispose();
Logger.Info("Exiting program.");
}
}