Enabling Open API on Azure Functions

01-func-init.sh

func init MyFunctionApp --worker-runtime dotnet

02-func-new.sh

func new --name DefaultHttpTrigger --language C#  --template "HTTP trigger"

03-default-http-trigger.cs

public static class DefaultHttpTrigger
{
    [FunctionName("DefaultHttpTrigger")]
    public static async Task<IActionResult> Run(
        [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
        ILogger log)
    {
        ...
    }
}

04-func-start.sh

func host start

05-dotnet-add-package.sh

dotnet add package Microsoft.Azure.WebJobs.Extensions.OpenApi \
                   --version 0.5.1-preview

06-default-http-trigger.cs

public static class DefaultHttpTrigger
{
    [OpenApiOperation(operationId: "Run", tags: new[] { "name" })]
    [OpenApiParameter(name: "name", In = ParameterLocation.Query, Required = true, Type = of(string), Description = "The **Name** parameter")]
    [OpenApiResponseWithBody(statusCode: HttpStatusCode.OK, contentType: "text/plain", bodyType: typeof(string), Description = "The OK response")]

    [FunctionName("DefaultHttpTrigger")]
    public static async Task<IActionResult> Run(
        [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
        ILogger log)
    {
        ...
    }
}

07-default-http-trigger.cs

public static class DefaultHttpTrigger
{
    [OpenApiOperation(operationId: "Run", tags: new[] { "name" })]
    [OpenApiParameter(name: "name", In = ParameterLocation.Query, Required = true, Type = of(string), Description = "The **Name** parameter")]
    [OpenApiResponseWithBody(statusCode: HttpStatusCode.OK, contentType: "text/plain", bodyType: typeof(string), Description = "The OK response")]

    [OpenApiSecurity("function_key", SecuritySchemeType.ApiKey, Name = "code", In = OpenApiSecurityLocationType.Query)]

    [FunctionName("DefaultHttpTrigger")]
    public static async Task<IActionResult> Run(
        [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
        ILogger log)
    {
        ...
    }
}