Rendering Swagger Definitions on Azure Functions

render-swagger-function.cs

public class RenderSwaggerFunction : FunctionBase<ILogger>, IRenderSwaggerFunction
{
    private readonly HttpClient _http;
    ...

    public RenderSwaggerFunction(AppSettings settings, HttpClient http)
    {
        this._http = http ?? throw new ArgumentNullException(nameof(http));
        ...
    }

    public override async Task<TOutput> InvokeAsync<TInput, TOutput>(TInput input, FunctionOptionsBase options = null)
    {
        ...

        // Get Swagger definitions from the given URL.
        var swagger = await this._http.GetStringAsync(this._settings.Swagger.ImportUrl)
                                      .ConfigureAwait(false);

        // Render as YAML
        if (IsYaml(opt.Extension))
        {
            return (TOutput)(IActionResult)new OkObjectResult(swagger);
        }

        // Render as JSON
        if (IsJson(opt.Extension))
        {
            var deserialiser = new DeserializerBuilder().Build();
            var deserialised = deserialiser.Deserialize<dynamic>(swagger);

            return (TOutput)(IActionResult)new OkObjectResult(deserialised);
        }

        throw new InvalidOperationException();
    }
}

swagger-trigger.cs

[FunctionName(nameof(RenderSwagger))]
public static async Task<IActionResult> RenderSwagger(
    [HttpTrigger(AuthorizationLevel.Function, "get", Route = "swagger.{extension}")] HttpRequest req,
    string extension,
    ILogger log)
{
    var result = await Factory.Create<IRenderSwaggerFunction, ILogger>(log)
                              .InvokeAsync<HttpRequest, IActionResult>(req, options)
                              .ConfigureAwait(false);

    return result;
}

swagger.yaml

swagger: "2.0"
info:
  description: "This is a custom Key Vault connector for Logic App."
  version: "1.0.0"
  title: "Key Vault Connector"
  termsOfService: "https://raw.githubusercontent.com/aliencube/Key-Vault-Connector-for-Logic-Apps/master/LICENSE"
  contact:
    url: "https://github.com/aliencube/Key-Vault-Connector-for-Logic-Apps/issues"
  license:
    name: "MIT"
    url: "https://raw.githubusercontent.com/aliencube/Key-Vault-Connector-for-Logic-Apps/master/LICENSE"
externalDocs:
  description: "Find out more about Key Vault Custom Connector"
  url: "https://github.com/aliencube/Key-Vault-Connector-for-Logic-Apps"
host: "keyvaultconnector.azurewebsites.net"
basePath: "/api"
tags:
- name: "secrets"
  description: "Access to the list of secrets"
  externalDocs:
    description: "Find out more"
    url: "https://github.com/aliencube/Key-Vault-Connector-for-Logic-Apps"
- name: "secret"
  description: "Access to the secret"
  externalDocs:
    description: "Find out more"
    url: "https://github.com/aliencube/Key-Vault-Connector-for-Logic-Apps"
schemes:
- "https"
paths:
  /secrets:
    get:
      tags:
      - "secrets"
      summary: "Gets the list of secretes"
      description: "This returns the list of secrets without their values"
      operationId: "Secrets"
      produces:
      - "application/json"
      x-ms-visibility: "important"
      responses:
        200:
          description: "OK"
          schema:
            type: "array"
            items:
              $ref: "#/definitions/SecretItem"
        404:
          description: "Not Found"
          schema:
            $ref: "#/definitions/Error"
        500:
          description: "Internal Server Error"
          schema:
            $ref: "#/definitions/Error"
      security:
      - authkey: []
  /secrets/{name}:
    get:
      tags:
      - "secret"
      summary: "Gets the secret details"
      description: "This returns a secreet details including its value"
      operationId: "Secret"
      produces:
      - "application/json"
      x-ms-visibility: "important"
      parameters:
      - name: "name"
        in: "path"
        description: "Secret name"
        required: true
        type: "string"
        x-ms-summary: "Name"
        x-ms-visibility: "important"
      responses:
        200:
          description: "OK"
          schema:
            $ref: "#/definitions/Secret"
        404:
          description: "Not Found"
          schema:
            $ref: "#/definitions/Error"
        500:
          description: "Internal Server Error"
          schema:
            $ref: "#/definitions/Error"
      security:
      - authkey: []
securityDefinitions:
  authkey:
    type: "apiKey"
    name: "x-functions-key"
    in: "header"
definitions:
  SecretItem:
    type: "object"
    properties:
      id:
        type: "string"
      name:
        type: "string"
      enabled:
        type: "boolean"
      managed:
        type: "boolean"
      contentType:
        type: "string"
      recoveryLevel:
        type: "string"
      created:
        type: "string"
        format: "date-time"
      updated:
        type: "string"
        format: "date-time"
      expires:
        type: "string"
        format: "date-time"
      notBefore:
        type: "string"
        format: "date-time"
    required:
    - id
    - name
    - enabled
    - recoveryLevel
  Secret:
    type: "object"
    properties:
      id:
        type: "string"
      name:
        type: "string"
      value:
        type: "string"
      enabled:
        type: "boolean"
      managed:
        type: "boolean"
      version:
        type: "string"
      contentType:
        type: "string"
      recoveryLevel:
        type: "string"
      created:
        type: "string"
        format: "date-time"
      updated:
        type: "string"
        format: "date-time"
      expires:
        type: "string"
        format: "date-time"
      notBefore:
        type: "string"
        format: "date-time"
    required:
    - id
    - name
    - enabled
    - recoveryLevel
  Error:
    type: "object"
    properties:
      statusCode:
        type: "integer"
      message:
        type: "string"
    required:
    - statusCode
    - message