App service website not starting after seemingly successful deploy

Question

I'm doing the Decompose a monolithic application into a microservices architecture course and am stuck on step 7 of Exercise - Deploy a monolithic application on App Service.

Although the deploy in step 6 seems to have completed successfully and the portal shows that the web app service is running, when I hit the URL for it I get HTTP Error 500.30 - ASP.NET Core app failed to start and have no idea how to figure out why. This is not something I've written but just following provided steps so I don't understand why there would be problems with it. The AI provided answer is suggesting things that would be useful if it was my own application rather than a provided sample one.

Answer 1

Hi Steve Crane,

Thanks for posting on Q&A platform.

There may be a few reasons behind the error which you can only identify by debugging. You can try to debug this error using the steps below:

1. Navigate to the root directory of the application using CMD
2. Run the application using the command dotnet run (yourApplicationName).dll

If there are any errors, they should appear in the output.

Alternatively, you can check "Event Viewer" (search Event Viewer using Windows search) and navigate to

• Windows Logs
  • Application There may be a few reasons behind the error which you can only identify by debugging. You can try to debug this error using the steps below:

Have a look at the below link, a similar thread, hope it helps.

reference - https://stackoverflow.com/questions/67211060/http-error-500-30-asp-net-core-app-failed-to-start

Please press the Accept Answer /Upvote option if you find this helpful.

Answer 2

The error message HTTP Error 500.30 - ASP.NET Core app failed to start indicates that the ASP.NET Core app failed to start. This error can occur due to a variety of reasons, including missing or incorrect configuration files, missing dependencies, or incorrect deployment. To diagnose the issue, you can start by checking the logs for any error messages. You can also try redeploying the app and ensuring that all the necessary files and dependencies are included in the deployment package.

Here are some steps you can take to diagnose and fix the issue:

1. Check the logs: You can check the logs for any error messages that might indicate the cause of the issue. You can find the logs in the Azure portal under the "Log stream" tab for your app service.
2. Redeploy the app: Try redeploying the app and ensuring that all the necessary files and dependencies are included in the deployment package. You can use your normal method of deployment, such as Visual Studio, PowerShell, or manual deployment.
3. Check the configuration files: Ensure that the configuration files, such as the web.config file, are present in the deployment and that their contents are correct.
4. Check the dependencies: Ensure that all the necessary dependencies are included in the deployment package. You can compare the deployment on the hosting system to the contents of the project's publish folder to confirm that all of the app's files and folders are deployed.
5. Check the deployment folder: Ensure that the app is deployed to the correct folder on the hosting system. When hosting on Azure App Service, confirm that the app is deployed to the D:\home\site\wwwroot folder. When the app is hosted by IIS, confirm that the app is deployed to the IIS Physical path shown in IIS Manager's Basic Settings.

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References:

• Troubleshoot ASP.NET Core on Azure App Service and IIS