Integrating HealthCheck endpoint into swagger (open API) UI on dotnet core

Question

I am using Dotnet Core healthchecks as described here. In short, it looks like this:

First, you configure services like this:

services.AddHealthChecks()
    .AddSqlServer("connectionString", name: "SQlServerHealthCheck")
    ... // Add multiple other checks

Then, you register an endpoint like this:

app.UseHealthChecks("/my/healthCheck/endpoint");

We are also using Swagger (aka Open API) and we see all the endpoints via Swagger UI, but not the health check endpoint.

Is there a way to add this to a controller method so that Swagger picks up the endpoint automatically, or maybe integrate it with swagger in another way?

The best solution I found so far is to add a custom hardcoded endpoint (like described here), but it is not nice to maintain.

Answer 1

Still looking for a better solution, but a poor man's solution to this problem looks like this:

public const string HealthCheckEndpoint = "/my/healthCheck/endpoint";

public void Apply(SwaggerDocument swaggerDoc, DocumentFilterContext context)
{
    var pathItem = new PathItem();
    pathItem.Get = new Operation()
    {
        Tags = new[] { "ApiHealth" },
        Produces = new[] { "application/json" }
    };

    var properties = new Dictionary<string, Schema>();
    properties.Add("status", new Schema(){ Type = "string" });
    properties.Add("errors", new Schema(){ Type = "array" });
    
    var exampleObject = new { status = "Healthy", errors = new List<string>()};

    pathItem.Get.Responses = new Dictionary<string, Response>();
    pathItem.Get.Responses.Add("200", new Response() {
        Description = "OK",
        Schema = new Schema() {
            Properties = properties,
            Example = exampleObject }});

    swaggerDoc.Paths.Add(HealthCheckEndpoint, pathItem);
}