Issue with "launch URL" in launchsettings.json file of my ASP.Net Core project to create a REST API

Jonathan Manoharan 1

I need to create a REST API simulating some typical bank operations. I have created an ASP.Net Core project and use a Code first approach with Entity Framework. I have successfully created the database and the REST CRUD functions.

I have two controllers in my project :- BankMembersController.cs and UserAccountsController.cs. I have attached the BankMembersController.cs file and launchSettings.json files.

In the launchSettings.json file, I have modified the "launchUrl" field to "api/bankMember" in the "profiles" and "Bank_Account" sections.

When I run the program using IIS Express and Google Chrome as the browser, a page renders with the following error information: for the URL https://localhost:44335/api/bankMember :-

Bad Request - Invalid Hostname
133983-launchsettings.txt 133939-bankmemberscontroller.txt
HTTP Error 400. The request hostname is invalid.

I have tried varios combinations for the "launchUrl" field e.g. BankMember, bankMembers, but all with same error message.

Further there is a second Controller call UserAccountsController. That is not currently mentioned in the launchsettings.json file.

Any help much appreciated!

AgaveJoe 26,136 Reputation points

2021-09-21T14:29:44.84+00:00
The launch setting should be set in the profiles section for IIS Express.

"profiles": { "IIS Express": { "commandName": "IISExpress", "launchBrowser": true, "launchUrl": "api/bankMember", "environmentVariables": { "ASPNETCORE_ENVIRONMENT": "Development" } },

The Bank_Account section is used when you change IIS Express to Bank_Account and run the project.

Keep in mind, launchSettings.json only applies to running the project from Visual Studio.
Jonathan Manoharan 1 Reputation point

2021-09-21T19:58:12.003+00:00

Hi @AgaveJoe ,

The code that you listed is exactly the same as the text file I listed originally, so your suggestion won't make any difference. Thanks anyway. I have been running the project using IIS Express and know that the launchSettings.json file is only used for localhost development.
Brando Zhang-MSFT 2,956 Reputation points Microsoft Vendor

2021-09-23T07:38:59.753+00:00

Hi @Jonathan Manoharan ,

As far as I know, the HTTP Error 400. The request hostname is invalid. is not related with launch url, it is related with your IIS binding information. Could you please tell me where you hosted your application IIS express or you have hosted this application on IIS now. Could you please tell me if you directly run this application, is it working well ?
Jonathan Manoharan 1 Reputation point

2021-09-23T07:54:16.667+00:00

Hi @Brando Zhang-MSFT

First let me thank you for helping me! Much appreciated. I thought it was the launch URL, even though all the resarch I've done says that the launch URL I set is correct.

IIS binding information:- I am developing this on my home desktop, so when I run the program it's localhost and I select the option IIS Express (google chrome is the web browser) and hit the play button.
So in answer to your question I believe I am running the application directly on my desktop using IIS Express as the web server. I'm not sure what you mean by IIS binding information. I am using the default settings for IIS Express.

Please give me some very specific questions, so we can resolve this. Once again thanks for your help!
Brando Zhang-MSFT 2,956 Reputation points Microsoft Vendor

2021-09-23T09:24:14.747+00:00

Hi @Jonathan Manoharan ,

Could you please tell me if you remove the launchUrl settings and your web application will running well when you click the VS's start button?
Jonathan Manoharan 1 Reputation point

2021-09-23T10:06:51.447+00:00

Ok, If I understood you correctly, I commented out the line like ths:-
//"launchUrl": "api/bankMember", //TODO

Ran the progaram and got the same result
Jonathan Manoharan 1 Reputation point

2021-09-23T10:53:23.413+00:00

I also excluded the launchSettings.json file and ran the program. Same result again -Bad Request HTTP Error 400
Jonathan Manoharan 1 Reputation point

2021-09-23T11:16:47.13+00:00

I have also installed the project on another machine and get the same result. so default IIS settings. I'm also using an SSL certificate generated by IIS
Brando Zhang-MSFT 2,956 Reputation points Microsoft Vendor

2021-09-24T07:23:20.057+00:00

I guess there is something wrong with your applicationhost.config IISexpress binding settings.

I suggest you could try to go to C:\Users\{UserName}\Documents\Visual Studio 2019\Projects\{SolutionName}\.vs\config\applicationhost.config to check if the stie bingding is like below format.

<binding protocol="https" bindingInformation="*:44302:localhost" />
Jonathan Manoharan 1 Reputation point

2021-09-24T08:05:08.057+00:00

Hi @Brando Zhang-MSFT ,

I used to build my projects from the Projects.... paths as you mentioned. However, the paths pathe set by Visual Studio is: Users{UserName}\source\repos{Solution Name}. Wondering if that is the problem? I don't think it should be. I will relocate it to the Documents path as you specified and investigate by running the program.

Also I could not find the .vs directory under {SolutionName}, which was concerning as this should be autogenerated

Jonathan Manoharan 1

Hi @Bruce Zhang-MSFT ,

II found the "applicationhost.config" file (the folder was hidden). Binding are as follows:

  <site name="WebSite1" id="1" serverAutoStart="true">  
    <application path="/">  
      <virtualDirectory path="/" physicalPath="%IIS_SITES_HOME%\WebSite1" />  
    </application>  
    <bindings>  
      <binding protocol="http" bindingInformation=":8080:localhost" />  
    </bindings>  
  </site>  
  <site name="Bank Account" id="2">  
    <application path="/" applicationPool="Bank Account AppPool">  
      <virtualDirectory path="/" physicalPath="C:\Users\jonat\source\repos\Bank Account\Bank Account" />  
    </application>  
    <bindings>  
      <binding protocol="http" bindingInformation="*:57934:localhost" />  
      <binding protocol="https" bindingInformation="*:44335:localhost" />  
    </bindings>  
  </site>

This is an auto- generated file. Are you thinking ther is a port conflict?? There are two sets of bindings. I wasn't sure which one you wer referring to?

Also I copied the project from the repos path to the Documenst folder and excuted. No difference

Jonathan Manoharan 1 Reputation point

2021-09-24T09:01:13.63+00:00

Also, I notice in the applicationhost.config file:-

<sites>
<site name="WebSite1" id="1" serverAutoStart="true">
<application path="/">
<virtualDirectory path="/" physicalPath="%IIS_SITES_HOME%\WebSite1" />
</application>
<bindings>
<binding protocol="http" bindingInformation=":8080:localhost" />
</bindings>
</site>

Do you think site name ="WebSite1" is a problem?