Fix provideRunner with no managers enabled.

cmd/poseidon/main.go

@@ -341,6 +341,13 @@ func createManagerHandler(ctx context.Context, handler managerCreator, enabled b
 	return runnerManager, environmentManager
 }
 
+func createAbstractManager(ctx context.Context) (
+	runnerManager runner.Manager, environmentManager environment.ManagerHandler,
+) {
+	runnerManager = runner.NewAbstractManager(ctx)
+	return runnerManager, environment.NewAbstractManager(runnerManager)
+}
+
 func createNomadManager(ctx context.Context) (runner.Manager, environment.ManagerHandler) {
 	// API initialization
 	nomadAPIClient, err := nomad.NewExecutorAPI(ctx, &config.Config.Nomad)
@@ -400,8 +407,9 @@ func createAWSManager(ctx context.Context) (
 
 // initRouter builds a router that serves the API with the chain of responsibility for multiple managers.
 func initRouter(ctx context.Context) *mux.Router {
-	runnerManager, environmentManager := createManagerHandler(ctx, createNomadManager, config.Config.Nomad.Enabled,
-		nil, nil)
+	runnerManager, environmentManager := createManagerHandler(ctx, createAbstractManager, true, nil, nil)
+	runnerManager, environmentManager = createManagerHandler(ctx, createNomadManager, config.Config.Nomad.Enabled,
+		runnerManager, environmentManager)
 	runnerManager, environmentManager = createManagerHandler(ctx, createAWSManager, config.Config.AWS.Enabled,
 		runnerManager, environmentManager)
 

internal/api/environments.go

@@ -128,6 +128,7 @@ func (e *EnvironmentController) createOrUpdate(writer http.ResponseWriter, reque
 	})
 	if err != nil {
 		writeInternalServerError(request.Context(), writer, err, dto.ErrorUnknown)
+		return
 	}
 
 	if created {

internal/environment/abstract_manager.go

@@ -15,6 +15,14 @@
 	runnerManager runner.Manager
 }
 
+// NewAbstractManager creates a new abstract runner manager that keeps track of all environments of one kind.
+func NewAbstractManager(runnerManager runner.Manager) *AbstractManager {
+	return &AbstractManager{
+		nextHandler:   nil,
+		runnerManager: runnerManager,
+	}
+}
+
 func (n *AbstractManager) SetNextHandler(next ManagerHandler) {
 	n.nextHandler = next
 }
@@ -41,7 +49,7 @@
 func (n *AbstractManager) CreateOrUpdate(_ context.Context, _ dto.EnvironmentID, _ dto.ExecutionEnvironmentRequest) (
 	bool, error,
 ) {
-	return false, nil
+	return false, dto.ErrNotSupported
 }
 
 func (n *AbstractManager) Delete(environmentID dto.EnvironmentID) (bool, error) {

internal/runner/abstract_manager.go

@@ -12,7 +12,7 @@ import (
 	"github.com/openHPI/poseidon/pkg/storage"
 )
 
-var ErrNullObject = errors.New("functionality not available for the null object")
+var ErrUnknownExecutionEnvironment = errors.New("execution environment not found")
 
 // AbstractManager is used to have a fallback runner manager in the chain of responsibility
 // following the null object pattern.
@@ -99,7 +99,7 @@ func (n *AbstractManager) EnvironmentStatistics() map[dto.EnvironmentID]*dto.Sta
 }
 
 func (n *AbstractManager) Claim(_ dto.EnvironmentID, _ int) (Runner, error) {
-	return nil, ErrNullObject
+	return nil, ErrUnknownExecutionEnvironment
 }
 
 func (n *AbstractManager) Get(runnerID string) (Runner, error) {

internal/runner/nomad_manager.go

@@ -24,10 +24,9 @@
 const environmentMigrationDelay = time.Minute
 
 var (
-	log                            = logging.GetLogger("runner")
-	ErrUnknownExecutionEnvironment = errors.New("execution environment not found")
-	ErrNoRunnersAvailable          = errors.New("no runners available for this execution environment")
-	ErrRunnerNotFound              = errors.New("no runner found with this id")
+	log                   = logging.GetLogger("runner")
+	ErrNoRunnersAvailable = errors.New("no runners available for this execution environment")
+	ErrRunnerNotFound     = errors.New("no runner found with this id")
 )
 
 type alertData struct {
@@ -50,8 +49,13 @@
 func (m *NomadRunnerManager) Claim(environmentID dto.EnvironmentID, duration int) (Runner, error) {
 	environment, ok := m.GetEnvironment(environmentID)
 	if !ok {
-		return nil, ErrUnknownExecutionEnvironment
+		r, err := m.NextHandler().Claim(environmentID, duration)
+		if err != nil {
+			return nil, fmt.Errorf("nomad wrapped: %w", err)
+		}
+		return r, nil
 	}
+
 	runner, ok := environment.Sample()
 	if !ok {
 		return nil, ErrNoRunnersAvailable

internal/runner/nomad_manager_test.go

@@ -117,7 +117,7 @@ func (s *ManagerTestSuite) TestSetEnvironmentAddsNewEnvironment() {
 func (s *ManagerTestSuite) TestClaimReturnsNotFoundErrorIfEnvironmentNotFound() {
 	runner, err := s.nomadRunnerManager.Claim(anotherEnvironmentID, defaultInactivityTimeout)
 	s.Nil(runner)
-	s.Equal(ErrUnknownExecutionEnvironment, err)
+	s.ErrorIs(err, ErrUnknownExecutionEnvironment)
 }
 
 func (s *ManagerTestSuite) TestClaimReturnsRunnerIfAvailable() {