Iis 502 ошибка

I ran into this same problem when I deployed my application. There were several problems on my end

I went through this page very carefully: ASP.NET Core: Publishing to IIS

First, I didn’t have all parts of the .NET Core Windows Server Hosting bundle installed. I ended up doing a fremework-dependent deployment instead of a self-contained deployment. We have a lot of apps and don’t want/need each on their own versions of .net core. There would be way too many versions of .net on the box.

Also, note that if your admins performed any updates/upgrades to the server, they could have jacked up your ASP.NET Core installation (see ASP.NET Core: Publishing to IIS troubleshooting section)

Then, I had to fix my web.config… here is my working published web.config:
I didn’t publish as an *.exe, I did *.dll (notice my arguments value). Also, my processPath is set to «dotnet».

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <system.webServer>
    <handlers>
      <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModule" resourceType="Unspecified" />
    </handlers>
    <aspNetCore processPath="dotnet" arguments=".DT.Web.dll" stdoutLogEnabled="false" stdoutLogFile=".logsstdout" forwardWindowsAuthToken="false" />
  </system.webServer>
</configuration>

Also, ensure that your project.json options are all set compatible with your server environment (see ASP.NET Core: Publishing to IIS troubleshooting section)

Here is a copy of the of my project.json if it can be of any help:

{
  "version": "2.0.1.0",

  "dependencies": {
    "DT.Common": "2.*",
    "DT.Configuration": "2.*",
    "DT.Services": "2.*",
    "DT.Web.ViewModels": "2.*",
    "Microsoft.ApplicationInsights.AspNetCore": "1.0.2",
    "Microsoft.AspNetCore.Authentication": "1.1.0",
    "Microsoft.AspNetCore.Authentication.Cookies": "1.1.0",
    "Microsoft.AspNetCore.Authentication.OpenIdConnect": "1.1.0",
    "Microsoft.AspNetCore.Diagnostics": "1.1.0",
    "Microsoft.AspNetCore.Mvc": "1.1.0",
    "Microsoft.AspNetCore.Razor.Tools": {
      "version": "1.1.0-preview4-final",
      "type": "build"
    },
    "Microsoft.AspNetCore.Routing": "1.1.0",
    "Microsoft.AspNetCore.Server.IISIntegration": "1.1.0",
    "Microsoft.AspNetCore.Server.IISIntegration.Tools": {
      "version": "1.1.0-preview4-final",
      "type": "build"
    },
    "Microsoft.AspNetCore.Server.Kestrel": "1.1.0",
    "Microsoft.AspNetCore.Server.Kestrel.Https": "1.1.0",
    "Microsoft.AspNetCore.Session": "1.0.0",
    "Microsoft.AspNetCore.StaticFiles": "1.1.0",
    "Microsoft.Extensions.Caching.SqlServer": "1.0.0",
    "Microsoft.Extensions.Configuration.Abstractions": "1.1.0",
    "Microsoft.Extensions.Configuration.FileExtensions": "1.1.0",
    "Microsoft.Extensions.Configuration.Json": "1.1.0",
    "Microsoft.Extensions.Logging.Console": "1.1.0",
    "Microsoft.Extensions.Logging.Debug": "1.1.0",
    "Microsoft.Extensions.Options.ConfigurationExtensions": "1.0.0",
    "Microsoft.Graph": "1.1.1",
    "Microsoft.IdentityModel.Clients.ActiveDirectory": "3.13.6"
  },

  "tools": {
    "Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.1.0-preview4-final",
    "Microsoft.AspNetCore.Razor.Tools": {
      "version": "1.1.0-preview4-final",
      "imports": "portable-net45+win8+dotnet5.6"
    },
    "Microsoft.Extensions.Caching.SqlConfig.Tools": "1.1.0-preview4-final"
  },

  "frameworks": {
    "netcoreapp1.1": {
      "imports": [
        "dotnet5.6",
        "portable-net45+win8"
      ],
      "dependencies": {
        "Microsoft.NETCore.App": {
          "version": "1.1.0",
          "type": "platform"
        }
      }
    }
  },

  "buildOptions": {
    "emitEntryPoint": true,
    "preserveCompilationContext": true
  },

  "runtimeOptions": {
    "configProperties": {
      "System.GC.Server": true
    }
  },

  "publishOptions": {
    "include": [
      "wwwroot",
      "views/**/*.cshtml",
      "appsettings.json",
      "appsettings.*.json",
      "web.config"
    ]
  },

  "scripts": {
    "prepublish": [ "bower install", "gulp buildprod" ],
    "postpublish": [ "dotnet publish-iis --publish-folder %publish:OutputPath% --framework %publish:FullTargetFramework%" ]
  }
}

When deploying an ASP.NET Core application to IIS, you may find IIS returning HTTP Error 502.5 instead of your web page.

I recently hit this problem after manually modifying the web.config file. Fortunately, the problem is easy to fix.

In this post, we see two different causes of this error, two different solutions for the first cause, a solution for the second cause, and learn what needs to be in web.config for ASP.NET Core to operate.

The Error

Here is a screenshot of the HTTP Error 502.5 - Process Failure error. You’ll see this, in your browser, when making a request to your ASP.NET Core application, after deployment, if you have this issue.

Why do I get the error?

The HTTP Error 502.5 - Bad Gateway and HTTP Error 502.5 - Process Failure error messages occur in ASP.NET Core when IIS fails to execute the dotnet process.

I’ve seen this error happen for two different reasons:

1. .NET Core Runtime is not installed
2. web.config file has not been transformed

Fix 1a: Install the .NET Core Runtime

The most common reason for this to occur is when you haven’t installed the .NET Core runtime on the server.

You can download the latest .NET Core runtime from Microsoft’s .NET download page.

For Windows, you’ll usually want the latest .NET Core runtime (currently v2.1.1), as highlighted in the following screenshot:

This will get you the Windows Hosting Bundle Installer, which will install both the x86 and x64 runtimes on Windows Server.

Fix 1b: Publish a Self-Contained Deployment

If you don’t want to install the .NET Core Runtime. An alternative for .NET Core web applications is to publish them in the Self-Contained deployment mode, which includes the required .NET Runtime files alongside your application.

You can select this option from the advanced publish settings screen in Visual Studio:

If you go with this option, you’ll also need to choose a target runtime: win-x86, win-x64, osx-x64, or linux-x64. Because self-contained deployments are not portable.

Fix 2: Transform your web.config file

Another reason for this error to occur is when you deploy an untransformed web.config file.

This is likely to be your issue if you had a previously working web application and merely deployed a new version of it.

ASP.NET Core Web Config

In ASP.NET Core applications, the web.config file contains a handler that directs requests to the AspNetCoreModule and an aspNetCore element that defines and configures the ASP.NET Core process to execute your web application.

Here is a minimal web.config file for an ASP.NET Core application:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <system.webServer>
    <handlers>
      <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModule" resourceType="Unspecified" />
    </handlers>
    <aspNetCore processPath="%LAUNCHER_PATH%" arguments="%LAUNCHER_ARGS%" stdoutLogEnabled="true" 
        stdoutLogFile=".logsstdout" forwardWindowsAuthToken="false"/>
  </system.webServer>
</configuration>

Note that it’s possible that you don’t have a web.config file in your ASP.NET Core project. If you do not, one will be generated for you when publishing the project, as IIS and IIS Express require a web.config file when hosting an ASP.NET Core web app.

The Issue

The untransformed web.config contains the variables %LAUNCHER_PATH% and %LAUNCHER_ARGS% rather than the correct paths. When IIS tries to run ASP.NET Core, it uses %LAUNCHER_PATH% and %LAUNCHER_ARGS% rather than the correct path and arguments.

To fix the HTTP Error 502.5 in ASP.NET Core, you need to transform the web.config and replace the untransformed web.config file on the IIS web server.

How do I transform web.config?

This transformation takes place when you choose to publish your web application. The transformed web.config ends up in the published output folder. Therefore, you simply need to publish your web application and copy the resulting web.config file onto the server.

In a transformed web.config file, the aspNetCore element will look something like this:

<aspNetCore processPath="dotnet" arguments=".MyApplication.dll" stdoutLogEnabled="true" 
    stdoutLogFile=".logsstdout" forwardWindowsAuthToken="false" />

%LAUNCHER_PATH% has been replaced by dotnet and %LAUNCHER_ARGS% has been replaced by the path to the main web application dll .MyApplication.dll.

Addendum

Update (4th July 2018): The same error occurs when the .NET Core Runtime is not installed. So, I have updated the article to include the solution to this more common issue as well.

The HyperText Transfer Protocol (HTTP) 502 Bad Gateway the server error is generated when an invalid response is received from a server. “502 Bad Gateway” is an HTTP status code that is defined and standardized with RFC. The “502 Bad Gateway” status code is defined in RFC 10.5.3.

HTTP uses status codes in order to provide information about the HTTP request between client and servers. Every HTTP request will return a HTTP status code like successful, failed, warning etc. The web is complex where some servers can make HTTP request to other servers too. “HTTP 502 Bad Gateway” is a status code is mainly returned from a server where this server make some request to other server and can not get information and “HTTP 502 Bad Gateway” is returned to the user.

“HTTP 502 Bad Gateway” Expressions

Even the canonical name for the “HTTP 502 Bad Gateway” is used to express the error but there are other expressions to show this error. The following errors are generally used for the web.

• 502 Bad Gateway
• 502 Service Temporarily Overloaded
• Error 502
• Temporary Error (502)
• 502 Proxy Error
• 502 Server Error: The server encountered a temporary error and could not complete your request
• HTTP 502
• 502. That’s an error
• Bad Gateway: The proxy server received an invalid response from an upstream server
• HTTP Error 502 – Bad Gateway
• 502 Bad Gateway NGINX
• A blank white screen

Also other than different applications, software, operating systems uses the web for different purposes and can get “HTTP 502 Bad Gateway” error and print in different forms.

Windows Update requires to access th update servers which uses HTTP protocol to get information. The following error is returned which is related with the “HTTP 502 Bad Gateway” status code.

0x80244021 error code or the message WU_E_PT_HTTP_STATUS_BAD_GATEWAY

Google provides a lot of web related services like Gmail, Google Search, Google Cloud, Google Drive Google Map etc. These service may return the “HTTP 502 Bad Gateway” error like below.

Linux Package Management command named “apt-get” uses HTTP in order to get recent package information and issue an “Error 502 Bad Gateway” error.

W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/trusty-security/main/source/Sources  502  Bad Gateway [IP: 91.189.91.13 80]

Linux Yum is another package manager for RPM based distributions and the HTTP 502 Error is expressed like below.

error was [Errno 14] HTTP Error 502: Bad Gateway

What Cause “HTTP 502 Bad Gateway” Error?

“HTTP 502 Bad Gateway” error is mainly related to the communication problems between intermediate servers. This means we have no control over this error.

• Browser Problem
• DNS Problem
• Firewall Configuration
• Internet Access
• Remote Website Problem
• Server Overload
• Website Software Error

Microsoft IIS “HTTP 502 Bad Gateway” SubStatus Information

Microsoft IIS version 7.0 and later provides more detailed information about the “HTTP 502 Bad Gateway” error. It provides sub status code like “502.1”, “502.2” where every sub status code provides a specific case. This sub status information is not standard and only provided by the Microsoft IIS server.

• 502.1 – CGI application timeout.
• 502.2 – Bad gateway: Premature Exit.
• 502.3 – Bad Gateway: Forwarder Connection Error (ARR).
• 502.4 – Bad Gateway: No Server (ARR).

How To Fix /Solve “HTTP 502 Bad Gateway” Error?

The “HTTP 502 Bad Gateway” error can be solved in different ways. Event the error is mainly related with the remote server or network there are some basic checks in order to fix or overcome this error.

Client Side Solutions

Reload URL is the first and most practical way to solve this error. “F5” or refresh button of the web browser can be used. Actually this will not fix the problem directly but just make a check if the problem continue or not.

Start New Session is another quick fix where previous sessions garbage will be omitted.

Clear your browser cache where outdated or corrupted files that are stored in the browser will be removed which can cause “HTTP 502 Bad Gateway” error.

Delete Cookies because previosuly stored cookies will use old values for an HTTP connection which can be cause of the “502 Bad Gateway” error.

Start Browsers in Safe/Private Mode which will omit previously craeted sessions and site preferences and prevent “502 Error”.

Try Different Browser where current browser may have problems. Try different browser like Google Chrome, Mozilla Firefox, Microsoft Edge, Opera, Internet Explorer, Safari etc.

Disable Security Softwarewhere security software can block suspicious even legitimate action. Security software like Microsoft Defender, Kaspersky Endpoint Protection, Microsoft Forefront, TrendMicro Endpoint Protection etc. generally monitors network traffic and stops suspicious connections.

Restart Computer because some temporary configuration may prevent access to network and create “HTTP 502 Bad Gateway” error.

Restart Network Devices because they provide access to the internet and problem related with these devices will interrupt internet access which will cause “Bad Gateway Error”.

Change DNS Server is related with your computer or router. Some “HTTP 502 Bad Gateway” errors are related with the DNS server errors or restrictions.

Server/Network Side Solutions

Contact website owner is responsible for the website you want to access. The problem may be related with the website architecture where you can contact website owner for the problem.

Contact ISP because the internet connection is provided by the ISP where it can be responsible for the “502 Bad Gateway” error.

Check origin server where it can be down for the CDN architecture.

Check Firewall Configuration and Logswhere server firewall can prevent some transfer between client or servers which will cause “HTTP 502 Bad Gateway” error.

Check Server Software where it may provide faulty responses or create unnecessary overload.

Check Server Services where services may be unreliable. If it is possible to restart the services and look for configuration changes.

Check Database Server because slow queries slowdown the websites and cause sow responses which will end with timeout and “HTTP 502 Bad Gateway” error.

Check Hosting Provider where there may a system or network problem related to the hosting which effects the web site.

Different “HTTP 502 Bad Gateway” Error Pages

Below we will list some popular services “HTTP 502 Bad Gateway” error pages.

Cloudflare

GoDaddy

Twitter

Google

Microsoft IIS

Nginx