Adding endpoint concept to keymaster

endpoint.scala

/******* Option-1: **********/

  /**
   * Keymaster Config:
   * 
   * "keymaster" {
   *   "upstreamEndpoints" : {
   *     identityProvider" : {
   *       "hosts" : "localhost:8081", // CSV of servers
   *       "path" : "/identityProvider" // use this path upstream
   *     },
   *     "accessIssuer" : {
   *       "hosts" : "localhost:8081", // CSV of servers
   *       "path" : "/accessIssuer" // use this path upstream
   *     },
   *     "loginForm" : {
   *       "hosts" : "localhost:8081", // CSV of servers
   *       "path" : null // use actual url on upstream
   *     }
   *   },
   *   unauthenticatedEndpoints: [{ // all Methods
   *     "hosts" : "localhost:8081", // CSV of servers
   *     "path" : "/a/recover" // path to match on request
   *   }]
   * }
   */
  case class Endpoint(hosts: String, path: Option[Path])
  case class KeymasterUpstreamEndpoints(identityProvider: Endpoint, accessIssuer: Endpoint, loginForm: Endpoint)
  case class KeymasterConfig(upstreamEndpoints: KeymasterUpstreamEndpoints, unauthenticatedEndpoints: List[Endpoint])

  // Top level Routing Service
  // Keymaster specific
  // Method.any -> /a/login => KeymasterMethodMuxLoginFilter andThen KeymasterIdpService
  // Method.any -> /a/recover => EndpointService(endpoint) // This is direct access; a sort of opening a pinhole in our firewall
  // Method.any -> _ => allOtherRequests

  // How to instantiate  "KeymasterMethodMuxLoginFilter" 
  // - IMO KeymasterMethodMuxLoginFilter we should limit this to "GET /a/login" => loginForm and "POST /a/login" => keymasterIdpService
  KeymasterMethodMuxLoginFilter(keymasterConfig.upstreamEndpoints.loginForm) {
    case Method.Get -> keymasterConfig.upstreamEndpoints.loginForm
    case Method.post -> continue to KeymasterLoginFilter andThen KeymasterIdentityService
    case _ => Request.NotFound
  }

  
/******* Option-2: **********/

  /**
   * Keymaster Config:
   * 
   * "keymaster" {
   *   "path" : "/a"
   *   "upstreamEndpoints" : {
   *     identityProvider" : {
   *       "hosts" : "localhost:8081", // CSV of servers
   *       "path" : "/a/login", 
   *       "upstreamPath" : "/identityProvider" // use this path upstream
   *     },
   *     "accessIssuer" : {
   *       "hosts" : "localhost:8081", // CSV of servers
   *       "path" : null, // Not necessary
   *       "upstreamPath" : "/accessIssuer" // use this path upstream
   *     },
   *     "loginForm" : {
   *       "hosts" : "localhost:8081", // CSV of servers
   *       "path" : "/a/login" // use actual url on upstream
   *       "upstreamPath" : null // optional; but use this path upstream
   *     }
   *   },
   *   unauthenticatedEndpoints: [{ // all Methods
   *     "hosts" : "localhost:8081", // CSV of servers
   *     "path" : "/a/recover",
   *     "upstreamPath" : null // optional; but use this path upstream
   *   }]
   * }
   */
  case class Endpoint(hosts: String, path: Option[Path], upstreamPath: Option[Path])
  case class KeymasterUpstreamEndpoints(identityProvider: Endpoint, accessIssuer: Endpoint, loginForm: Endpoint)
  case class KeymasterConfig(path: Path, upstreamEndpoints: KeymasterUpstreamEndpoints, unauthenticatedEndpoints: List[Endpoint])

  // Top level Routing Service
  // Keymaster specific
  // Method.any -> keymasterConfig.path / _ => KeymasterMethodMuxLoginFilter andThen KeymasterLoginService andThen KeymasterIdentityProvider
  // Method.any -> _ => allOtherRequests

  // How to instantiate  "KeymasterMethodMuxLoginFilter" 
  KeymasterMethodMuxLoginFilter(keymasterConfig.upstreamEndpoints.loginForm) {
    //  We are assuming keymasterConfig.upstreamEndpoints.loginForm.path is same as keymasterConfig.upstreamEndpoints.identityProvider.path
    case Method.Get -> keymasterConfig.upstreamEndpoints.path => Httpx.newClient(keymasterConfig.upstreamEndpoints.loginForm.hosts)(request)
    case Method.Post -> keymasterConfig.upstreamEndpoints.loginForm.path => continue to KeymasterLoginFilter andThen KeymasterIdentityService
    case _ -> keymasterConfig.upstreamEndpoints.loginForm.path => Request.BadRequest
    case _ -> path in keymasterConfig.unauthenticatedEndpoints(x) => Httpx.newClient(x.hosts)(request)
    case _ => Request.BadRequest
  }

  /******* Option-3: **********/

  /**
   * Keymaster Config:
   * 
   * "keymaster" {
   *   "path" : "/a"
   *   identityProvider" : {
   *     "inputPath" : "/a/login", 
   *     "upstreamHosts" : "localhost:8081", // CSV of servers
   *     "upstreamPath" : "/identityProvider" // use this path upstream
   *   },
   *   "accessIssuer" : {
   *     "inputPath" : null, // Not necessary
   *     "upstreamHosts" : "localhost:8081", // CSV of servers
   *     "upstreamPath" : "/accessIssuer" // use this path upstream
   *   },
   *   "routes" : [{
   *     "inputMethod" : "GET", 
   *     "inputPath" : "/a/login", 
   *     "upstreamHosts" : "localhost:8081", // CSV of servers
   *     "upstreamPath" : null // use inputPath as upstreamPath
   *   },{
   *     "inputMethod" : "*", // all paths 
   *     "inputPath" : "/a/recover", 
   *     "upstreamHosts" : "localhost:8081", // CSV of servers
   *     "upstreamPath" : null // use inputPath as upstreamPath
   *   }]
   * }
   */
  case class Route(inputMethod: Option[Method], inputPath: Option[Path], upstreamHosts: String, upstreamPath: Option[Path])
  case class KeymasterConfig(path: Path, identityProvider: Route, accessIssuer: Route, routes: Route)

  // Top level Routing Service
  // Keymaster specific
  // Method.any -> keymasterConfig.path / _ => KeymasterMethodMuxLoginFilter andThen KeymasterLoginService andThen KeymasterIdentityProvider
  // Method.any -> _ => allOtherRequests

  // How to instantiate  "KeymasterMethodMuxLoginFilter" 
  KeymasterMethodMuxLoginFilter(keymasterConfig) {
    val routeMap = keymasterConfig.routes.map(r => (r.method, r.path) -> r)
    case Method.Post -> keymasterConfig.identityProvider.inputPath => continue to KeymasterLoginFilter andThen KeymasterIdentityService
    routeMap(req.method, req.path) match {
      case Some(r) => Httpx.newClient(r.upstreamHosts)(request)
      case None => BadRequest
  }