How to effectively set the ServerUrl in the NSwag settings? - asp.net-core

I have a working ASP .NET 5 application with a REST API and a Swagger interface using the NSwag library (so not Swashbuckle as many people use instead). I have found (or at least I have thought so) a way to set the server url. There is a property to set this. Here is my code:
app.UseSwaggerUi3(settings =>
{
settings.ServerUrl = "https://XXXXX.YYYYY.com/ZZZZ";
settings.TransformToExternalPath = (url, request) =>
{
// Get the UI to properly find the relative path of the swagger json instead of absolute path.
string outputUrl;
if (url.EndsWith(".json") || request.Path.ToString().EndsWith("/")) outputUrl = ".." + url;
else outputUrl = request.PathBase + "." + url;
return outputUrl;
};
});
However, when running my application and using the swagger interface, the set server url is not used at all... It simply refers to same host as it does without setting it. I know it is possible to change the routing behavior of swagger when needed (as explained here and I also used this code) but that basically solves the problem of not being able to find the swagger json. However, I did not find a way to effectively set the server url. When I use the code shown in this post, the request url when executing a request refers to the same url when not using it.
How can I fix this? How to effectively set the server url? This is so strange. I looks like the property does not do anything at all.

For me it seems to work well using the Host property in PostProcess. I set it to null to get the UI working for all incoming host names.
I'm on Owin version but same looks like it should work in 5/6 as well.
RouteTable.Routes.MapOwinPath("swagger", app =>
{
..
app.UseSwaggerUi3(typeof(Global).Assembly, c => {
// Fix to make UI work regardless of hostname serving
c.PostProcess = document => {
document.Host = null;
};
});
});
The ServerUrl property looks like it's only used as RedirectUrl in an eventual OAuth2 flow.

Related

Can't perform HTTP Post Action from Logic App to Asp.net Core Web API

I've built many Logic Apps. I've also integrated with the Logic App API. For some reason, a Post request to an Asp.net Core Web API won't work. It works in Postman, but I can't get Logic Apps to complete the request.
The request arrives at my Web API. I can step through it during a remote debug session. I'm using the [FromBody] decorator on the API method. All the string values in the object are null.
Logic App Headers
Accept = "application/json"
ContentType = "application/json"
ContentLength = "35"
Host = "****.centralus.logic.azure.com"
API method
[HttpPost]
[Route("CreateSomething")]
public async Task<IActionResult> CreateSomething([FromBody] MyObject object)
{
//Create something great
}
I think it might have something to do with the Headers. I noticed that the Postman request won't succeed unless I check the Host and Content-Length box in the Headers section. According to this article, Logic Apps ignores those Headers.
https://learn.microsoft.com/en-us/azure/connectors/connectors-native-http
I've built the HTTP Post Action using the API as well as configured it manually using the Logic App UI in Azure.
By the way, does anyone know the Expression that will automatically calculate the ContentLength?
UPDATE:
I finally figured this out. I had to do some Ninja coding crap to make this work. I'll post my solution tomorrow.
Does anyone know how to make this work? Thanks in advance!
When you use the Logic App API to programmatically create Logic Apps, you have to specify the Body class for when you do something like an HTTP Post. When the Body JSON displayed in the designer, it contained a single object with the objects properties. My API method could not handle this. The key was to simply post the properties in the JSON Body. To make matters worse, I'm doing two HTTP Posts in this particular Logic App. When I tried to add my object properties to the existing Body class, it caused my other HTTP Post to stop working. To overcome this, I had to create a Body2 class with the objects properties. I then had to use the following line of code to replace body2 with body before adding the JSON to the Logic App API call.
This did not work.
body = new Body()
{
object = new Object()
{
//Properties
}
}
This worked.
body2 = new Body2()
{
Type = 0,
Description = "#{items('For_each_2')?['day']?['description']}",
Locations = item.Locations,
Cold = "#{items('For_each_2')?['temperature']?['cold']?['value']}",
Hot = "#{items('For_each_2')?['temperature']?['hot']?['value']}",
Hide = 0
}
Notice I used Replace on body2.
var options = new JsonSerializerOptions { WriteIndented = true, IgnoreNullValues = true};
string jsonString = ReplaceFirst(JsonSerializer.Serialize(myApp, options), "schema", "$schema").Replace("_else", "else").Replace("_foreach", "foreach").Replace("body2", "body");

Get Swagger URL programmatically in ASP.NET Core

I'm using ASP.NET Core 5, and Swagger. I know how to use Swagger, and it works properly.
Swagger is served on foo:5001/swagger - but I need to determine that URL programmatically at runtime.
How can I do that?
I already tried:
Getting it by injecting IEnumerable<EndpointDataSource> into some helper/controller class, but that shows me all routes EXCEPT swagger's.
Getting it while setting up endpoint routing and inspecting IEndpointRouteBuilder, but once again it shows me all routes EXCEPT swagger's.
According to sources at https://github.com/domaindrivendev/Swashbuckle.AspNetCore/blob/master/src/Swashbuckle.AspNetCore.SwaggerUI/SwaggerUIMiddleware.cs you can use an instance of class SwaggerUIOptions:
Register instance in DI container:
var options = new SwaggerUIOptions
{
RoutePrefix = "swagger"
};
options.SwaggerEndpoint("/swagger/v1/swagger.json", "waiting_list v1");
services.AddSingleton(options);
Use configured instance:
app.UseSwaggerUI(app.ApplicationServices.GetRequiredService<SwaggerUIOptions>());
Inject instance to any controller/class:
public WeatherForecastController(ILogger<WeatherForecastController> logger, SwaggerUIOptions swaggerOptions)
{
}
Property RoutePrefix contains swagger prefix (without leading '/')
This idea works only if options object passed to UseSwaggerUI method (available since version 6.0.0). If UseSwaggerUI invoked using callback (like a UseSwaggerUI(a => { a.RoutePrefix = string.Empty; })) it won't work.

ASP.net Core web API Swagger UI version field - Is it possible to set this value in code?

I have a ASP.Net Core Web API with Swagger configured that shows the API End Points.Also API Versioning is enabled. However, the swagger UI is not populating the mandatory field Version when checking the End Point.See image below:
Is it possible to populate this field automatically by code given that the API Action already configures this value i.e. the MaptoApiVersion. In theory this field should be populated automatically??
[MapToApiVersion("2")]
[HttpGet("GetV2")]
[ProducesResponseType(StatusCodes.Status200OK)]
[ProducesResponseType(StatusCodes.Status500InternalServerError)]
public async Task<IEnumerable<TodoDto>> GetV2()
{
var query = new AllTodosQuery(_context);
var todos = await query.ExecuteAsync();
return todos;
}
The issue is at least two-fold. First, the extensions to the API Explorer from API Versioning do provide the version parameter with a default value, but many Swagger/OpenAPI generators (such as Swashbuckle) still do not yet honor it. If you want to enable this behavior, you need a custom IOperationFilter which does something to the effect of:
var parameter = operation.Parameters.First(p => p.Name == "version");
var description = context.ApiDescription.ParameterDescriptions.First(p => p.Name == "version");
if (parameter.Schema.Default == null && description.DefaultValue != null)
{
parameter.Schema.Default = new OpenApiString(description.DefaultValue.ToString());
}
You can find a complete end-to-end example in the API Versioning repo in:
SwaggerDefaultValues.cs
Since you're versioning by URL segment, if you want that inlined into the route template without a corresponding parameter, you need only configure the API Explorer extensions to do so like this:
services.AddVersionedApiExplorer(options => options.SubstituteApiVersionInUrl = true);
This option only applies to the URL segment versioning method.
A complete end-to-end Swashbuckle example with API Versioning can be found inside Startup.cs inside the repo.

Enabling binary media types breaks Option POST call (CORS) in AWS Lambda

New to AWS..
We have a .NET Core Microservice running on a serverless aws instance as lambda functions.
Our Controller looks like this
[Route("api/[controller]")]
[ApiController]
public class SomeController : ControllerBase
{
[HttpGet()]
[Route("getsomedoc")]
public async Task<IActionResult> GetSomeDoc()
{
byte[] content;
//UI needs this to process the document
var contentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment");
contentDisposition.FileName = "File Name";
Response.Headers[HeaderNames.ContentDisposition] = contentDisposition.ToString();
return File(content, "application/octet-stream");
}
[HttpPost()]
[Route("somepost")]
public async Task<IActionResult> SomePost()
{
return null;
}
}
URL's
{{URL}}/getsomedoc
{{URL}}/somepost
We have enabled 'Binary Media Types' in AWS package settings to / for the getsomedoc to work otherwise it was returning the byte array back instead of the file.
But this is breaking our 'somepost' call when UI is accessing the API using
Method: OPTIONS & Access-Control-Request-Method as POST
When we remove the binary media type the 'somepost' starts working.
Looking for suggestions as why this might be happening? and what can we add/remove from gateway to get this fixed.
Well we ended up resolving this in a strange way.
Added two gateways for the lambda
- on one of them have binary enabled
- Disabled on the other one.
For
getsomedoc - Using the one where binary media types are enabled
postsomedoc - Using the other one
Wish there was a better way!!
I have found this same behavior with my API. While looking everywhere for some help, I found a few things that address the issue:
Basically, this bug report says the problem is having CORS enabled while also using the generic Binary Media Type "*/*". Apparently the OPTIONS method gets confused by this. They discuss this in terms of using Serverless, but it should apply to using the console or other ways of interacting with AWS.
They link to a possible solution: you can modify the Integration Response of the OPTIONS method - change the Mapping Template's Content-Type to an actual binary media type, like image/jpeg. They say this allows you to leave the binary media type in Settings as "*/*". This is a little hacky, but at least it is something.
There also was this alternate suggestion in the issues section of this GitHub repo that is a little less hacky. You can set the content handling parameter of the OPTIONS Integration Request to "CONVERT_TO_TEXT"... but you can only do this via CloudFormation or the CLI (not via the console). This is also the recommended solution by some AWS Technicians.
Another possible workaround is to setup a custom Lambda function to handle the OPTIONS request, this way the API gateway may have the "*/*" Binary Media Type.
Create a new lambda function for handling OPTIONS requests:
exports.handler = async (event) => {
const response = {
statusCode: 200,
headers:{
'access-control-allow-origin':'*',
'Access-Control-Allow-Headers': 'access-control-allow-origin, content-type, access-control-allow-methods',
'Access-Control-Allow-Methods':"GET,POST,PUT,DELETE,OPTIONS"
},
body: JSON.stringify("OK")
};
return response;
};
In your API Gateway OPTION method, change the integration type from Mock to Lambda Function.
Make sure to check 'Use Lambda proxy integration'
Select the correct region and point to the created Lambda Function
This way any OPTIONS request made from the browser will trigger the Lambda function and return the custom response.
Be aware this solution might involve costs.

AssumeDefaultVersionWhenUnspecified is not working as expected

I have been using asp net core versioning component for my WebAPI. Need your help in understanding how AssumeDefaultVersionWhenUnspecified is working. (tried searching for documentation, but couldn't find one)
My startup looks like below
services.AddApiVersioning(o => {
o.ReportApiVersions = true;
o.AssumeDefaultVersionWhenUnspecified = true;
o.DefaultApiVersion = new ApiVersion(2, 0);
o.ApiVersionReader = new UrlSegmentApiVersionReader();
});
When the route attribute is something like below
[ApiVersion("2.0")]
[Route("api/v{version:apiVersion}/values")]
[ApiController]
public class ValuesV2Controller : ControllerBase
{
...
}
The above route works only when the api version is specified. ie: http://localhost:55401/api/v2/values
If I call like http://localhost:55401/api/values, getting 404 error
My question is this... How AssumeDefaultVersionWhenUnspecified works. Wouldn't it ignore the version in Route? Looks like Route attribute takes precedence over AssumeDefaultVersionWhenUnspecified. If I choose QueryString or Header versioning and when the Route looks like
[ApiVersion("2.0")]
[Route("api/values")]
the default routing reaches the API
Am I missing anything or is my understanding wrong? How shall I achieve default routing to the latest version API using url versioning?
I am also trying to achieve the same functionality. By looking into [https://github.com/Microsoft/aspnet-api-versioning/issues/351#issuecomment-425106940]
I am assuming that we can't achieve default API version AssumeDefaultVersionWhenUnspecified functionality with only a single style of versioning uses a URL segment [Route("api/v{version:apiVersion}/[controller]")]
We have to define two routes separately as follow
[Route("api/[controller]")]
[Route("api/v{version:apiVersion}/[controller]")]
and to hide the two implementations from swagger you can achieve using this link
Summarizing the the solution from the github issue linked by Athi S, here's what you need to do :
In ConfigureServices inside Startup.cs file :
services.AddApiVersioning(o =>
{
o.AssumeDefaultVersionWhenUnspecified = true;
o.ApiVersionSelector = new CurrentImplementationApiVersionSelector(o);
// o.DefaultApiVersion = new ApiVersion(1, 0);
});
You can optionally set ApiVersionSelector to a new instance of CurrentImplementationApiVersionSelector. What this does is, it automatically selects the highest api version registered in controllers. E.g. A controller decorated with [ApiVersion("1.2")] takes precedence over [ApiVersion("1.1")].
If you want to specify default api version explicitly, you can do so by leaving ApiVersionSelector to DefaultApiVersionSelector and setting DefaultApiVersion to your required api version.
In your controllers :
Register the required routes by decorating your controllers with the given Route attributes
[Route("api/[controller]")]
Or if you want the api to work both with and without the api version number specified, you can do so by declaring two routes for the controller.
[Route("api/[controller]")]
[Route("api/v{version:apiVersion}/[controller]")]