.Net Console Application works just fine until it is uploaded as Azure WebJob to Azure website. Code to replicate:
using System;
using System.Runtime.InteropServices;
using System.Windows.Input;
namespace ConsoleApplication2
{
class Program
{
[DllImport("user32.dll")]
private static extern uint MapVirtualKey(uint uCode, uint uMapType);
static void Main()
{
foreach (uint c in new uint[] {18, 31})
{
var mapped = (int) MapVirtualKey(c, 1);
Console.WriteLine($"{mapped} : {KeyInterop.KeyFromVirtualKey(mapped)}");
}
}
}
}
Expected output:
69 : E
83 : S
Actual output:
-1073741790 : None
-1073741790 : None
Not sure where to go from here. does it mean that access is denied for this api call?
The reason this doesn't work is that the MapVirtualKey API is blocked by the Azure Web App sandbox. You can learn more about the sandbox on https://github.com/projectkudu/kudu/wiki/Azure-Web-App-sandbox. See in particular this paragraph:
For the sake of radical attack surface area reduction, the sandbox prevents almost all of the Win32k.sys APIs from being called, which practically means that most of User32/GDI32 system calls are blocked. For most applications this is not an issue since most Azure Web Apps do not require access to Windows UI functionality (they are web applications after all).
Related
I have a web application acting as a gateway to a variety of internal services. These services are consumed by using a single instance of HttpClient, instantiated at startup (i.e. Startup.cs)
After a certain period of time, something is causing our HttpClient to stop hitting our APIs and immediately fail with HTTP 502 errors for every call using that client. (Note that I can still hit our APIs using other means, such as Postman)
Also be aware that this is all deployed to a variety of AppServices in Azure.
Any ideas as to what could corrupt HttpClient in this manner?
Thanks,
-Tim
This error is usually given when you are behind a proxy server.
If you are using a proxy you will probably have to authenticate the http client again.
Another possibility is to generate the Singleton instance again when it gives an error, for Example Singleton.killInstance(); If your implementation is like this:
public class Singleton
{
private static Singleton instance;
private Singleton() {}
public static Singleton instance
{
get
{
if (instance == null)
{
instance = new Singleton();
}
return instance;
}
}
public static void Singleton killInstance()
{
instance == null
}
}
Whatever the error might be, your httpclient request is causing your web server to crash. In order to investigate it, you need to go to to the Event Viewer of your AppService.
Here are the steps to launch the event viewer:
Go to Kudu management site of your website (ie https://{sitename}.scm.azurewebsites.net
Open menu item: Tools => Support
Choose relevant Azure AD Directory of your website
Click on Analyze => Event Viewer.
Check the error messages
How can I restart Web-Apps and API-Apps on Azure programmatically?
(I'd like to call it from another API-App within the same App service plan.)
There's also the "Microsoft Azure Management Libraries" Nuget that allows you to work with Azure services from inside of applications.
See this page for an example on how to create new web sites from inside of an Azure Web site. Restarting web services work in a similar way to creating new services. See this page for a list of available web site related methods.
Also, for authenticating is used certificate base authentication, see this page for more details on that.
Bellow is a short command line program that will restart all websites in all the webspaces you got in your Azure subscription. It works kinda like an iisreset for Azure Web Sites.
The code is based on samples taken from the links earlier mentioned:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.WindowsAzure.Management.WebSites;
using Microsoft.WindowsAzure;
using System.Security.Cryptography.X509Certificates;
using Microsoft.WindowsAzure.Management.WebSites.Models;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
var subscriptionId = "[INSERT_YOUR_SUBSCRIPTION_ID_HERE]";
var cred = new CertificateCloudCredentials(subscriptionId, GetCertificate());
var client = new WebSiteManagementClient(cred);
WebSpacesListResponse webspaces = client.WebSpaces.List();
webspaces.Select(p =>
{
Console.WriteLine("Processing webspace {0}", p.Name);
WebSpacesListWebSitesResponse websitesInWebspace = client.WebSpaces.ListWebSites(p.Name,
new WebSiteListParameters()
{
});
websitesInWebspace.Select(o =>
{
Console.Write(" - Restarting {0} ... ", o.Name);
OperationResponse operation = client.WebSites.Restart(p.Name, o.Name);
Console.WriteLine(operation.StatusCode.ToString());
return o;
}).ToArray();
return p;
}).ToArray();
if(System.Diagnostics.Debugger.IsAttached)
{
Console.WriteLine("Press anykey to exit");
Console.Read();
}
}
private static X509Certificate2 GetCertificate()
{
string certPath = Environment.CurrentDirectory + "\\" + "[NAME_OF_PFX_CERTIFICATE]";
var x509Cert = new X509Certificate2(certPath,"[PASSWORD_FOR_PFX_CERTIFICATE]");
return x509Cert;
}
}
}
Another alternative, if you can't find the function you need from the above mentioned library, you can also run powershell commands programmatically from inside of your application. You most likely will need to move, the application that is supposed to run these cmdlets, to a virtual machine to be able to load the needed powershell modules. See this page for more information on running powershell cmdlets programmatically.
You can use Powershell to do this. The relevant commands are:
Start-AzureWebsite -Name “xxxx”
Stop-AzureWebsite -Name “xxxx”
You can find help on these commands at the following links:
https://msdn.microsoft.com/en-us/library/azure/dn495288.aspx
https://msdn.microsoft.com/en-us/library/azure/dn495185.aspx
I think handling the base REST API is much better option. The Azure SDK changes quite a lot and lacks good documentation.
Here is an up-to-date sample code:
https://github.com/davidebbo/AzureWebsitesSamples/
You can adapt it to your needs.
Have you ever tried to run a hosted service in the windows azure emulator with full IIS and multiple role instances? Some days ago I noticed that only one of the multiple instances of a web role is startet in IIS at a time. The following screenshot illustrates the behavior and the message box in front of the screenshot shows the reason for this behavior. The message box appears on trying to start one of the stopped websites in the IIS Manager.
Screenshot: IIS with stopped Websites
The sample cloud application contains two web roles: MvcWebRole1 and WCFServiceWebRole1 each configured to use three instances. My first thought was: "Sure! No port collision will happen in the real azure world because every role instance is an own virtual machine. It cannot work in the emulator!" But after some research and analyzing many parts of the azure compute emulator I found out that the compute emulator creates a unique IP for each role instance (in my example from 127.255.0.0 up to 127.255.0.5). This MSDN blog article (http://blogs.msdn.com/b/avkashchauhan/archive/2011/09/16/whats-new-in-windows-azure-sdk-1-5-each-instance-in-any-role-gets-its-own-ip-address-to-match-compute-emulator-close-the-cloud-environment.aspx) of the microsoft employee Avkash Chauhan describes this behavior as well. After that conclusion I came to the following question: why the hell does the compute emulator (more precisely DevFC.exe) not add the IP of the appropriate role to the binding information of each Website???
I added the IP to each Website by hand and tadaaaaa: every Website can be started without any collisions. The next screenshot demonstrates it with the changed binding information highlighted.
Screenshot: IIS with started Websites
Once again: Why the hell does the emulator not do it for me? I wrote a small static helper method to do the binding extension thing for me on every role start. Maybe someone wants to use it:
public static class Emulator
{
public static void RepairBinding(string siteNameFromServiceModel, string endpointName)
{
// Use a mutex to mutually exclude the manipulation of the iis configuration.
// Otherwise server.CommitChanges() will throw an exeption!
using (var mutex = new System.Threading.Mutex(false, "AzureTools.Emulator.RepairBinding"))
{
mutex.WaitOne();
using (var server = new Microsoft.Web.Administration.ServerManager())
{
var siteName = string.Format("{0}_{1}", Microsoft.WindowsAzure.ServiceRuntime.RoleEnvironment.CurrentRoleInstance.Id, siteNameFromServiceModel);
var site = server.Sites[siteName];
// Add the IP of the role to the binding information of the website
foreach (Binding binding in site.Bindings)
{
//"*:82:"
if (binding.BindingInformation[0] == '*')
{
var instanceEndpoint = RoleEnvironment.CurrentRoleInstance.InstanceEndpoints[endpointName];
string bindingInformation = instanceEndpoint.IPEndpoint.Address.ToString() + binding.BindingInformation.Substring(1);
binding.BindingInformation = bindingInformation;
server.CommitChanges();
}
else
{
throw new InvalidOperationException();
}
}
}
// Start all websites of the role if all bindings of all websites of the role are prepared.
using (var server = new Microsoft.Web.Administration.ServerManager())
{
var sitesOfRole = server.Sites.Where(site => site.Name.Contains(RoleEnvironment.CurrentRoleInstance.Role.Name));
if (sitesOfRole.All(site => site.Bindings.All(binding => binding.BindingInformation[0] != '*')))
{
foreach (Site site in sitesOfRole)
{
if (site.State == ObjectState.Stopped)
{
site.Start();
}
}
}
}
mutex.ReleaseMutex();
}
}
}
I call the helper method as follows
public class WebRole : RoleEntryPoint
{
public override bool OnStart()
{
if (RoleEnvironment.IsEmulated)
{
AzureTools.Emulator.RepairBinding("Web", "ServiceEndpoint");
}
return base.OnStart();
}
}
I got it!
I have this behavior on three different machines which are all formatted and served with fresh clean windows 8, Visual Studio 2012 and Azure SDK 1.8 and Azure Tools installations recently. So a reinstallation of the Azure SDK and Tools (as Anton suggests) should not change anything. But the cleanliness of my three machines is the crucial point! Anton, do you have Visual Studio 2010 on your machine with at least VS2010 SP 1 installed? I analyzed IISConfigurator.exe with ILSpy and found the code which sets the IP in the binding information of the websites to '*' (instead of 127.255.0.*). It depends on the static property Microsoft.WindowsAzure.Common.Workarounds.BindToAllIpsWorkaroundEnabled. This method internally uses Microsoft.WindowsAzure.Common.Workarounds.TryGetVS2010SPVersion and leads to setting the IP binding to '*' if the SP level of Visual Studio 2010 is smaller than 1. TryGetVS2010SPVersion checks four registry keys and I don't know why but one of the keys exists in my registry und returns the Visual Studio 2010 SP level 0 (I never installed VS2010 on no one of the three machines!!!). As I changed the value of HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\DevDiv\vs\Servicing\10.0\SP from 0 to 10 (something greater 0 should do it) the Azure Emulator starts to set the 127.255.0.* IPs of the roles to the binding information on all of the websites in the IIS and all websites are started correctly.
I have an ASP.NET MVC 4 site running perfectly well in an Azure WebRole. The ASP.NET MVC project was started on its own, after which I added an Azure Cloud Service project to the solution and added the ASP.NET project/site as one of the 'roles' of the service (so it shows up in the 'Roles' folder).
My problem is that I would like to have working a WebRole.cs file within the ASP.NET MVC project, but no matter what I've tried to do, it appears that when deployed, it just never gets called. OnStart and the override of Run (which I know, must never leave the loop) -- these just apparently never get called.
But if you startup a new CloudService project and add, at that time from the start, an ASP.NET MVC project, it automatically has a WebRole.cs file in it, so my guess is that I need to configure something somewhere for the WebRole.cs (actually speaking, the WebRole class, which inherits RoleEntryPoint) to get called. What might that be?
using System;
using System.Web;
//using Microsoft.WindowsAzure.StorageClient;
using System.Diagnostics;
using System.Threading;
namespace Us.WebUI
{
public class WebRole : Microsoft.WindowsAzure.ServiceRuntime.RoleEntryPoint
{
public override bool OnStart()
{
return true; //return base.OnStart(); // CALL THIS???
}
public override void Run()
{
while (true) {
Thread.Sleep(TimeSpan.FromSeconds(30));
try {
EmailFuncs.SendEmailToUs("An email from our WebRole?????", "Email me this, email me that.");
}
catch { }
}
}
}
}
UPDATE: Thanks, the question has been answered. But I will add: On doing this, while it clearly was working (fully deployed and in emulator), that suddenly I was having problems doing a full publish of the site. After a azure publish took 3 hours:
Verifying storage account 'xyz'... > Uploading Package... > - Updating... [stayed here for 3 hours], it failed with this error: The server encountered an internal error. Please retry the request. So one thing I was wondering is, did I need to override OnStop in WebRole.cs?
UPDATE 2: Those previous problems were fixed, and had nothing to do with this issue. Actually, I've learned this: If you ever have any warnings generated in your build, Azure often will not work with them even when they don't cause problems locally or in other hosts. Since then, I've been much more studious to tackling build warnings (but critical to this is turning off with warning codes the many warning types you want to ignore!).
Adding a class to your Web Project which inherits from RoleEntryPoint is sufficient, it should just work. Did you try setting a breakpoint in the emulator?
What you might be experiencing is that EmailFuncs.SendEmailToUs requires info from the app/web.config and that this info is not available. You need to know that your WebRole class runs in a different process (not your web application), meaning it's not using your web.config. If you want the WebRole.cs to read info from the configuration file, you'll need to add these settings in WaIISHost.exe.config
I have written a custom Windows Service that writes data to a custom Event Log (in the Windows Event Viewer).
For dev'ing the biz logic that the service uses, I created a Windows Form which simulates the Start/Stop methods of the Windows Service.
When executing the biz logic via the Windows Forms, info is successfully written to my custom Event Log. However, when I run the same biz logic from the custom Windows Service, information is failing to be written to the Event Log.
To be clear, I have written a library (.dll) that does all the work that I want my custom service to do - including the create/write to the custom Event Log. My Form application references this library as does my Windows Service.
Thinking the problem is a security issue, I manually set the custom Windows Service to "Log on" as "Administrator", but the service still did not write to the Event Log.
I'm stuck on how to even troubleshoot this problem since I can't debug and step into the code when I run the service (if there is a way to debug a service, please share).
Do you have any ideas as to what could be causing my service to fail to write to the event log?
I use it like this. There can be some typos. Writed it on my phone browser...
public class MyClass
{
private EventLog eventLog = new EventLog();
public void MyClass()
{
if (!System.Diagnostics.EventLog.SourceExists("MyLogSource"))
System.Diagnostics.EventLog.CreateEventSource("MyLogSource", "MyLogSource_Log");
eventLog.Source = "MyLogSource";
eventLog.Log = "MyLogSource_Log";
}
private void MyLogWrite()
{
eventLog.WriteEntry(ex.ToString(), EventLogEntryType.Error);
}
}
To debug a running service you need to attach to the process. See here for the steps.
You could also add parameter checking to the Main entry point and have a combination service and console app which would start based on some flag. See this SO post for a good example but here's a snippet:
using System;
using System.ServiceProcess;
namespace WindowsService1
{
static class Program
{
static void Main(string[] args)
{
if (args == null)
{
Console.WriteLine("Starting service...");
ServiceBase.Run(new ServiceBase[] { new Service1() });
}
else
{
Console.WriteLine("Hi, not from service: " + args[0]);
}
}
}
}
The above starts the app in console mode if there any parameters exist and in service mode if there are no parameters. Of course it can be much fancier but that's the gist of the switch.
I discovered why my service wasn't writing to the Event Log.
The problem had nothing to do with any part of the code/security/etc that was attempting to write to the EL. The problem was that my service wasn't successfully collecting the information that is written to the EL - therefore, the service wasn't even attempting to write the log.
Now that I fixed the code that collects the data, data is successfully writing to the event log.
I'm open to having this question closed since the question was amiss to the real problem.