Add basic websocket structure and request upgrader

api/runners.go

@@ -32,12 +32,12 @@ func provideRunner(writer http.ResponseWriter, request *http.Request) {
 		writeNotFound(writer, err)
 		return
 	}
-	runner, err := env.NextRunner()
+	nextRunner, err := env.NextRunner()
 	if err != nil {
 		writeInternalServerError(writer, err, dto.ErrorNomadOverload)
 		return
 	}
-	sendJson(writer, &dto.RunnerResponse{Id: runner.Id()}, http.StatusOK)
+	sendJson(writer, &dto.RunnerResponse{Id: nextRunner.Id()}, http.StatusOK)
 }
 
 // executeCommand takes an ExecutionRequest and stores it for a runner.
@@ -80,14 +80,6 @@ func executeCommand(router *mux.Router) func(w http.ResponseWriter, r *http.Requ
 	}
 }
 
-// connectToRunner is a placeholder for now and will become the endpoint for websocket connections.
-func connectToRunner(writer http.ResponseWriter, request *http.Request) {
-	// Todo: Execute the command, upgrade the connection to websocket and handle forwarding
-	executionId := request.URL.Query()[ExecutionIdKey]
-	log.WithField("executionId", executionId).Info("Websocket for execution requested.")
-	writer.WriteHeader(http.StatusNotImplemented)
-}
-
 // The findRunnerMiddleware looks up the runnerId for routes containing it
 // and adds the runner to the context of the request.
 func findRunnerMiddleware(runnerPool environment.RunnerPool) func(handler http.Handler) http.Handler {

api/websocket.go

@@ -0,0 +1,46 @@
+package api
+
+import (
+	"errors"
+	"github.com/gorilla/websocket"
+	"gitlab.hpi.de/codeocean/codemoon/poseidon/api/dto"
+	"gitlab.hpi.de/codeocean/codemoon/poseidon/runner"
+	"net/http"
+)
+
+var connUpgrade = websocket.Upgrader{
+	ReadBufferSize:  1024,
+	WriteBufferSize: 1024,
+}
+
+// connectToRunner is a placeholder for now and will become the endpoint for websocket connections.
+func connectToRunner(writer http.ResponseWriter, request *http.Request) {
+	r, ok := runner.FromContext(request.Context())
+	if !ok {
+		log.Error("Runner not set in request context.")
+		writeInternalServerError(writer, errors.New("findRunnerMiddleware failure"), dto.ErrorUnknown)
+		return
+	}
+	executionId := request.URL.Query().Get(ExecutionIdKey)
+	connClient, err := connUpgrade.Upgrade(writer, request, nil)
+	if err != nil {
+		writeInternalServerError(writer, err, dto.ErrorUnknown)
+		return
+	}
+	defer func(connClient *websocket.Conn) {
+		err := connClient.Close()
+		if err != nil {
+			writeInternalServerError(writer, err, dto.ErrorUnknown)
+		}
+	}(connClient)
+
+	// ToDo: Implement communication forwarding
+	err, ok = r.Execute(runner.ExecutionId(executionId))
+	if !ok {
+		writeBadRequest(writer, errors.New("invalid Execution Id"))
+		return
+	} else if err != nil {
+		writeInternalServerError(writer, err, dto.ErrorUnknown)
+		return
+	}
+}

api/websocket_test.go

@@ -0,0 +1,12 @@
+package api
+
+import (
+	"testing"
+)
+
+func TestInvalidExecutionId(t *testing.T) {
+
+}
+
+func TestEstablishWebsocketConnection(t *testing.T) {
+}