diff --git a/api/websocket_test.go b/api/websocket_test.go
index b0a1f38..40559ee 100644
--- a/api/websocket_test.go
+++ b/api/websocket_test.go
@@ -370,9 +370,9 @@ func TestCodeOceanToRawReaderReturnsOnlyAfterOneByteWasReadFromConnection(t *tes
 
 // --- Test suite specific test helpers ---
 
-func newNomadAllocationWithMockedAPIClient(runnerID string) (r runner.Runner, mock *nomad.ExecutorAPIMock) {
-	mock = &nomad.ExecutorAPIMock{}
-	r = runner.NewNomadJob(runnerID, nil, mock, nil)
+func newNomadAllocationWithMockedAPIClient(runnerID string) (r runner.Runner, executorAPIMock *nomad.ExecutorAPIMock) {
+	executorAPIMock = &nomad.ExecutorAPIMock{}
+	r = runner.NewNomadJob(runnerID, nil, executorAPIMock, nil)
 	return
 }
 
diff --git a/nomad/nomad_test.go b/nomad/nomad_test.go
index 65cfe77..17deb3d 100644
--- a/nomad/nomad_test.go
+++ b/nomad/nomad_test.go
@@ -755,3 +755,35 @@ func (s *ExecuteCommandTestSuite) mockExecute(command interface{}, exitCode int,
 		Run(runFunc).
 		Return(exitCode, err)
 }
+
+func TestAPIClient_LoadRunnerPortMappings(t *testing.T) {
+	apiMock := &apiQuerierMock{}
+	mockedCall := apiMock.On("allocation", tests.DefaultRunnerID)
+	nomadAPIClient := APIClient{apiQuerier: apiMock}
+
+	t.Run("should return error when API query fails", func(t *testing.T) {
+		mockedCall.Return(nil, tests.ErrDefault)
+		portMappings, err := nomadAPIClient.LoadRunnerPortMappings(tests.DefaultRunnerID)
+		assert.Nil(t, portMappings)
+		assert.ErrorIs(t, err, tests.ErrDefault)
+	})
+
+	t.Run("should return error when AllocatedResources is nil", func(t *testing.T) {
+		mockedCall.Return(&nomadApi.Allocation{AllocatedResources: nil}, nil)
+		portMappings, err := nomadAPIClient.LoadRunnerPortMappings(tests.DefaultRunnerID)
+		assert.ErrorIs(t, err, ErrorNoAllocatedResourcesFound)
+		assert.Nil(t, portMappings)
+	})
+
+	t.Run("should correctly return ports", func(t *testing.T) {
+		allocation := &nomadApi.Allocation{
+			AllocatedResources: &nomadApi.AllocatedResources{
+				Shared: nomadApi.AllocatedSharedResources{Ports: tests.DefaultPortMappings},
+			},
+		}
+		mockedCall.Return(allocation, nil)
+		portMappings, err := nomadAPIClient.LoadRunnerPortMappings(tests.DefaultRunnerID)
+		assert.NoError(t, err)
+		assert.Equal(t, tests.DefaultPortMappings, portMappings)
+	})
+}
diff --git a/runner/manager_test.go b/runner/manager_test.go
index 1e481d0..20265b2 100644
--- a/runner/manager_test.go
+++ b/runner/manager_test.go
@@ -284,3 +284,64 @@ func modifyMockedCall(apiMock *nomad.ExecutorAPIMock, method string, modifier fu
 		}
 	}
 }
+
+func (s *ManagerTestSuite) TestOnAllocationAdded() {
+	s.registerDefaultEnvironment()
+	s.Run("does not add environment template id job", func() {
+		alloc := &nomadApi.Allocation{JobID: TemplateJobID(tests.DefaultEnvironmentIDAsInteger)}
+		s.nomadRunnerManager.onAllocationAdded(alloc)
+		job, ok := s.nomadRunnerManager.environments.Get(tests.DefaultEnvironmentIDAsInteger)
+		s.True(ok)
+		s.Zero(job.idleRunners.Length())
+	})
+	s.Run("does not panic when environment id cannot be parsed", func() {
+		alloc := &nomadApi.Allocation{JobID: ""}
+		s.NotPanics(func() {
+			s.nomadRunnerManager.onAllocationAdded(alloc)
+		})
+	})
+	s.Run("does not panic when environment does not exist", func() {
+		nonExistentEnvironment := EnvironmentID(1234)
+		_, ok := s.nomadRunnerManager.environments.Get(nonExistentEnvironment)
+		s.Require().False(ok)
+
+		alloc := &nomadApi.Allocation{JobID: RunnerJobID(nonExistentEnvironment, "1-1-1-1")}
+		s.NotPanics(func() {
+			s.nomadRunnerManager.onAllocationAdded(alloc)
+		})
+	})
+	s.Run("adds correct job", func() {
+		s.Run("without allocated resources", func() {
+			alloc := &nomadApi.Allocation{
+				JobID:              tests.DefaultJobID,
+				AllocatedResources: nil,
+			}
+			s.nomadRunnerManager.onAllocationAdded(alloc)
+			job, ok := s.nomadRunnerManager.environments.Get(tests.DefaultEnvironmentIDAsInteger)
+			s.True(ok)
+			runner, ok := job.idleRunners.Get(tests.DefaultJobID)
+			s.True(ok)
+			nomadJob, ok := runner.(*NomadJob)
+			s.True(ok)
+			s.Equal(nomadJob.id, tests.DefaultJobID)
+			s.Empty(nomadJob.portMappings)
+		})
+		s.Run("with mapped ports", func() {
+			alloc := &nomadApi.Allocation{
+				JobID: tests.DefaultJobID,
+				AllocatedResources: &nomadApi.AllocatedResources{
+					Shared: nomadApi.AllocatedSharedResources{Ports: tests.DefaultPortMappings},
+				},
+			}
+			s.nomadRunnerManager.onAllocationAdded(alloc)
+			job, ok := s.nomadRunnerManager.environments.Get(tests.DefaultEnvironmentIDAsInteger)
+			s.True(ok)
+			runner, ok := job.idleRunners.Get(tests.DefaultJobID)
+			s.True(ok)
+			nomadJob, ok := runner.(*NomadJob)
+			s.True(ok)
+			s.Equal(nomadJob.id, tests.DefaultJobID)
+			s.Equal(nomadJob.portMappings, tests.DefaultPortMappings)
+		})
+	})
+}
diff --git a/runner/runner_test.go b/runner/runner_test.go
index be8b6f3..db957a3 100644
--- a/runner/runner_test.go
+++ b/runner/runner_test.go
@@ -25,6 +25,14 @@ func TestIdIsStored(t *testing.T) {
 	assert.Equal(t, tests.DefaultJobID, runner.ID())
 }
 
+func TestMappedPortsAreStoredCorrectly(t *testing.T) {
+	runner := NewNomadJob(tests.DefaultJobID, tests.DefaultPortMappings, nil, nil)
+	assert.Equal(t, tests.DefaultMappedPorts, runner.MappedPorts())
+
+	runner = NewNomadJob(tests.DefaultJobID, nil, nil, nil)
+	assert.Empty(t, runner.MappedPorts())
+}
+
 func TestMarshalRunner(t *testing.T) {
 	runner := NewNomadJob(tests.DefaultJobID, nil, nil, nil)
 	marshal, err := json.Marshal(runner)
diff --git a/tests/constants.go b/tests/constants.go
index 52a139e..40bc963 100644
--- a/tests/constants.go
+++ b/tests/constants.go
@@ -2,6 +2,8 @@ package tests
 
 import (
 	"errors"
+	nomadApi "github.com/hashicorp/nomad/api"
+	"gitlab.hpi.de/codeocean/codemoon/poseidon/api/dto"
 	"time"
 )
 
@@ -28,5 +30,7 @@ const (
 )
 
 var (
-	ErrDefault = errors.New("an error occurred")
+	ErrDefault          = errors.New("an error occurred")
+	DefaultPortMappings = []nomadApi.PortMapping{{To: 42, Value: 1337, Label: "lit", HostIP: "127.0.0.1"}}
+	DefaultMappedPorts  = []*dto.MappedPort{{ExposedPort: 42, HostAddress: "127.0.0.1:1337"}}
 )