Deploying dotnetcore 5 web api to iis gives 404

After searching and messing with Startup.cs file I notice that

    app.UseSwagger();
    app.UseSwaggerUI(c => c.SwaggerEndpoint("/swagger/v1/swagger.json", "api v1"));

Was inside the validation if(env.IsDevelopment()), but the api endpoints were working just fine, just that though that it doesn't work because I was unable to see the Swagger site, probably because you don't want to expose your api to everyone... feels like I miss a little explanation somewhere but all good now.

Faced the same issue. After configuring, when tried to browse 404 error came up.

The reason is, Swagger page will be configured in only for development environment as below(in Startup.cs).

 if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
                app.UseSwagger();
                app.UseSwaggerUI(c => c.SwaggerEndpoint("/swagger/v1/swagger.json", "AppName v1"));
        }

The APIs will be available if we type in the correct url. If you still wants to view the Swagger file

• Either change the code in startup.cs remove the check for

  if (env.IsDevelopment())

• Or In your web.config file set environment as Development.

If you have deployed a NET5 API to local IIS for development propose, you should set the environment to development using the web.config file

<aspNetCore processPath="dotnet" arguments=".\NewDealerWebAPI.dll" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" hostingModel="inprocess" >
          <environmentVariables>
            <environmentVariable name="ASPNETCORE_ENVIRONMENT" value="Development" />
          </environmentVariables>
      </aspNetCore

You can solve your problem by following the steps on this site.

https://docs.microsoft.com/en-us/aspnet/core/tutorials/getting-started-with-swashbuckle?view=aspnetcore-3.1&tabs=visual-studio

You didnt specify where you're pointing to swagger or directly to the api?

Additional things to check with OpenApi/Swagger/Swashbuckle/whatever the name is this week: If you're going to https://yourAppUri/swagger/index.html

• As noted in other replies, if you deploy to production, the environment may be different so the "if (env.IsDevelopment())..." is in your program.cs or startup.cs and your server has the "Production" or "Staging" value set, you'll get a 404 because swagger isn't found or generated because of that if statement.
  • There is a hierarchy to where the env vars are set if you're unsure. Basically its in this order: command line, environment variables, user secrets, appsettings.someEnvironment.json, then finally appsettings.json.
• Verify that in your .csproj file it contains the following in the PropertyGroup tag (I had recently generated a new api project via the cli and the below was conveniently left out:

...
<GenerateDocumentationFile>true</GenerateDocumentationFile>
<NoWarn>$(NoWarn);1591</NoWarn>   
</PropertyGroup>

• For internal APIs, I completely remove the if statement to always generate the swagger docs so end users can use it, but also force an api key so its semi locked down.

For hitting the api (since there's no controller code in your question):

• Validate your url is correct, I'd copy the url after visual studio or rider starts up with and replace localhost with your server name/info and hit it with PostMan or something similar
• Verify you dont have other bindings set in IIS, is the host environment using different ports to go to like: 8080.

Most other things would throw a 500 error I can think of...