Implement even more merge request comments

ci/demo-job.tpl.nomad

@@ -1,6 +1,6 @@
 // This job is used by the e2e tests as a demo job.
 
-job "0-default" {
+job "template-0" {
   datacenters = ["dc1"]
   type = "batch"
   namespace = "${NOMAD_NAMESPACE}"
@@ -49,4 +49,30 @@ job "0-default" {
       }
     }
   }
+  group "config" {
+      // We want to store whether a task is in use in order to recover from a downtime.
+      // Without a separate config task, marking a task as used would result in a restart of that task,
+      // as the meta information is passed to the container as environment variables.
+      count = 0
+      task "config" {
+        driver = "exec"
+        config {
+          command = "whoami"
+        }
+        logs {
+          max_files     = 1
+          max_file_size = 1
+        }
+        resources {
+          // minimum values
+          cpu    = 1
+          memory = 10
+        }
+      }
+      meta {
+        environment = "0"
+        used = "false"
+        prewarmingPoolSize = "1"
+      }
+    }
 }

environment/manager.go

@@ -13,18 +13,23 @@ import (
 	"strconv"
 )
 
-// defaultJobHCL holds our default job in HCL format.
+// templateEnvironmentJobHCL holds our default job in HCL format.
 // The default job is used when creating new job and provides
 // common settings that all the jobs share.
-//go:embed default-job.hcl
+//go:embed template-environment-job.hcl
-var defaultJobHCL string
+var templateEnvironmentJobHCL string
 
 var log = logging.GetLogger("environment")
 
 // Manager encapsulates API calls to the executor API for creation and deletion of execution environments.
 type Manager interface {
+	// Load fetches all already created execution environments from the executor and registers them at the runner manager.
+	// It should be called during the startup process (e.g. on creation of the Manager).
+	Load() error
+
 	// CreateOrUpdate creates/updates an execution environment on the executor.
-	// Iff the job was created, the returned boolean is true and the returned error is nil.
+	// If the job was created, the returned boolean is true, if it was updated, it is false.
+	// If err is not nil, that means the environment was neither created nor updated.
 	CreateOrUpdate(
 		id runner.EnvironmentID,
 		request dto.ExecutionEnvironmentRequest,
@@ -34,24 +39,27 @@ type Manager interface {
 	Delete(id string)
 }
 
-func NewNomadEnvironmentManager(runnerManager runner.Manager, apiClient nomad.ExecutorAPI) (
+func NewNomadEnvironmentManager(runnerManager runner.Manager,
-	*NomadEnvironmentManager, error) {
+	apiClient nomad.ExecutorAPI) (m *NomadEnvironmentManager) {
-	environmentManager := &NomadEnvironmentManager{runnerManager, apiClient, *parseJob(defaultJobHCL)}
+	m = &NomadEnvironmentManager{runnerManager, apiClient, *parseJob(templateEnvironmentJobHCL)}
-	err := environmentManager.loadExistingEnvironments()
+	if err := m.Load(); err != nil {
-	return environmentManager, err
+		log.WithError(err).Error("Error recovering the execution environments")
+	}
+	runnerManager.Load()
+	return
 }
 
 type NomadEnvironmentManager struct {
-	runnerManager runner.Manager
+	runnerManager          runner.Manager
-	api           nomad.ExecutorAPI
+	api                    nomad.ExecutorAPI
-	defaultJob    nomadApi.Job
+	templateEnvironmentJob nomadApi.Job
 }
 
 func (m *NomadEnvironmentManager) CreateOrUpdate(
 	id runner.EnvironmentID,
 	request dto.ExecutionEnvironmentRequest,
 ) (bool, error) {
-	templateJob, err := m.api.RegisterTemplateJob(&m.defaultJob, int(id),
+	templateJob, err := m.api.RegisterTemplateJob(&m.templateEnvironmentJob, runner.TemplateJobID(id),
 		request.PrewarmingPoolSize, request.CPULimit, request.MemoryLimit,
 		request.Image, request.NetworkAccess, request.ExposedPorts)
 
@@ -59,7 +67,7 @@ func (m *NomadEnvironmentManager) CreateOrUpdate(
 		return false, err
 	}
 
-	created, err := m.runnerManager.CreateOrUpdateEnvironment(id, request.PrewarmingPoolSize, templateJob)
+	created, err := m.runnerManager.CreateOrUpdateEnvironment(id, request.PrewarmingPoolSize, templateJob, true)
 	if err != nil {
 		return created, err
 	}
@@ -70,52 +78,13 @@ func (m *NomadEnvironmentManager) Delete(id string) {
 
 }
 
-func (m *NomadEnvironmentManager) loadExistingEnvironments() error {
+func (m *NomadEnvironmentManager) Load() error {
-	jobs, err := m.api.LoadAllJobs()
+	templateJobs, err := m.api.LoadEnvironmentJobs()
 	if err != nil {
-		return fmt.Errorf("can't load template jobs: %w", err)
+		return fmt.Errorf("couldn't load template jobs: %w", err)
 	}
 
-	var environmentTemplates, runnerJobs []*nomadApi.Job
+	for _, job := range templateJobs {
-	for _, job := range jobs {
-		if nomad.IsEnvironmentTemplateID(*job.ID) {
-			environmentTemplates = append(environmentTemplates, job)
-		} else {
-			runnerJobs = append(runnerJobs, job)
-		}
-	}
-	m.recoverJobs(environmentTemplates, m.recoverEnvironmentTemplates)
-	m.recoverJobs(runnerJobs, m.recoverRunner)
-
-	err = m.runnerManager.ScaleAllEnvironments()
-	if err != nil {
-		return fmt.Errorf("can not restore environment scaling: %w", err)
-	}
-	return nil
-}
-
-type jobAdder func(id runner.EnvironmentID, job *nomadApi.Job, configTaskGroup *nomadApi.TaskGroup) error
-
-func (m *NomadEnvironmentManager) recoverEnvironmentTemplates(id runner.EnvironmentID, job *nomadApi.Job,
-	configTaskGroup *nomadApi.TaskGroup) error {
-	desiredIdleRunnersCount, err := strconv.Atoi(configTaskGroup.Meta[nomad.ConfigMetaPoolSizeKey])
-	if err != nil {
-		return fmt.Errorf("Couldn't convert pool size to int: %w", err)
-	}
-
-	m.runnerManager.RecoverEnvironment(id, job, uint(desiredIdleRunnersCount))
-	return nil
-}
-
-func (m *NomadEnvironmentManager) recoverRunner(id runner.EnvironmentID, job *nomadApi.Job,
-	configTaskGroup *nomadApi.TaskGroup) error {
-	isUsed := configTaskGroup.Meta[nomad.ConfigMetaUsedKey] == nomad.ConfigMetaUsedValue
-	m.runnerManager.RecoverRunner(id, job, isUsed)
-	return nil
-}
-
-func (m *NomadEnvironmentManager) recoverJobs(jobs []*nomadApi.Job, onJob jobAdder) {
-	for _, job := range jobs {
 		jobLogger := log.WithField("jobID", *job.ID)
 		if *job.Status != structs.JobStatusRunning {
 			jobLogger.Info("Job not running, skipping ...")
@@ -126,6 +95,11 @@ func (m *NomadEnvironmentManager) recoverJobs(jobs []*nomadApi.Job, onJob jobAdd
 			jobLogger.Info("Couldn't find config task group in job, skipping ...")
 			continue
 		}
+		desiredIdleRunnersCount, err := strconv.Atoi(configTaskGroup.Meta[nomad.ConfigMetaPoolSizeKey])
+		if err != nil {
+			jobLogger.Infof("Couldn't convert pool size to int: %v, skipping ...", err)
+			continue
+		}
 		environmentID, err := runner.NewEnvironmentID(configTaskGroup.Meta[nomad.ConfigMetaEnvironmentKey])
 		if err != nil {
 			jobLogger.WithField("environmentID", configTaskGroup.Meta[nomad.ConfigMetaEnvironmentKey]).
@@ -133,12 +107,13 @@ func (m *NomadEnvironmentManager) recoverJobs(jobs []*nomadApi.Job, onJob jobAdd
 				Error("Couldn't convert environment id of template job to int")
 			continue
 		}
-		err = onJob(environmentID, job, configTaskGroup)
+		_, err = m.runnerManager.CreateOrUpdateEnvironment(environmentID, uint(desiredIdleRunnersCount), job, false)
 		if err != nil {
 			jobLogger.WithError(err).Info("Could not recover job.")
 			continue
 		}
 	}
+	return nil
 }
 
 func parseJob(jobHCL string) *nomadApi.Job {

environment/manager_mock.go

@@ -39,3 +39,17 @@ func (_m *ManagerMock) CreateOrUpdate(id runner.EnvironmentID, request dto.Execu
 func (_m *ManagerMock) Delete(id string) {
 	_m.Called(id)
 }
+
+// Load provides a mock function with given fields:
+func (_m *ManagerMock) Load() error {
+	ret := _m.Called()
+
+	var r0 error
+	if rf, ok := ret.Get(0).(func() error); ok {
+		r0 = rf()
+	} else {
+		r0 = ret.Error(0)
+	}
+
+	return r0
+}

environment/manager_test.go

@@ -50,20 +50,21 @@ func (s *CreateOrUpdateTestSuite) SetupTest() {
 
 func (s *CreateOrUpdateTestSuite) mockRegisterTemplateJob(job *nomadApi.Job, err error) {
 	s.apiMock.On("RegisterTemplateJob",
-		mock.AnythingOfType("*api.Job"), mock.AnythingOfType("int"),
+		mock.AnythingOfType("*api.Job"), mock.AnythingOfType("string"),
 		mock.AnythingOfType("uint"), mock.AnythingOfType("uint"), mock.AnythingOfType("uint"),
 		mock.AnythingOfType("string"), mock.AnythingOfType("bool"), mock.AnythingOfType("[]uint16")).
 		Return(job, err)
 }
 
 func (s *CreateOrUpdateTestSuite) mockCreateOrUpdateEnvironment(created bool, err error) {
-	s.runnerManagerMock.On("CreateOrUpdateEnvironment",
+	s.runnerManagerMock.On("CreateOrUpdateEnvironment", mock.AnythingOfType("EnvironmentID"),
-		mock.AnythingOfType("EnvironmentID"), mock.AnythingOfType("uint"), mock.AnythingOfType("*api.Job")).
+		mock.AnythingOfType("uint"), mock.AnythingOfType("*api.Job"), mock.AnythingOfType("bool")).
 		Return(created, err)
 }
 
 func (s *CreateOrUpdateTestSuite) createJobForRequest() *nomadApi.Job {
-	return nomad.CreateTemplateJob(&s.manager.defaultJob, tests.DefaultEnvironmentIDAsInteger,
+	return nomad.CreateTemplateJob(&s.manager.templateEnvironmentJob,
+		runner.TemplateJobID(tests.DefaultEnvironmentIDAsInteger),
 		s.request.PrewarmingPoolSize, s.request.CPULimit, s.request.MemoryLimit,
 		s.request.Image, s.request.NetworkAccess, s.request.ExposedPorts)
 }
@@ -76,7 +77,7 @@ func (s *CreateOrUpdateTestSuite) TestRegistersCorrectTemplateJob() {
 	s.NoError(err)
 
 	s.apiMock.AssertCalled(s.T(), "RegisterTemplateJob",
-		&s.manager.defaultJob, int(s.environmentID),
+		&s.manager.templateEnvironmentJob, runner.TemplateJobID(s.environmentID),
 		s.request.PrewarmingPoolSize, s.request.CPULimit, s.request.MemoryLimit,
 		s.request.Image, s.request.NetworkAccess, s.request.ExposedPorts)
 }
@@ -98,7 +99,7 @@ func (s *CreateOrUpdateTestSuite) TestCreatesOrUpdatesCorrectEnvironment() {
 	_, err := s.manager.CreateOrUpdate(s.environmentID, s.request)
 	s.NoError(err)
 	s.runnerManagerMock.AssertCalled(s.T(), "CreateOrUpdateEnvironment",
-		s.environmentID, s.request.PrewarmingPoolSize, templateJob)
+		s.environmentID, s.request.PrewarmingPoolSize, templateJob, true)
 }
 
 func (s *CreateOrUpdateTestSuite) TestReturnsErrorIfCreatesOrUpdateEnvironmentReturnsError() {
@@ -132,7 +133,7 @@ func TestParseJob(t *testing.T) {
 	log = logger.WithField("pkg", "nomad")
 
 	t.Run("parses the given default job", func(t *testing.T) {
-		job := parseJob(defaultJobHCL)
+		job := parseJob(templateEnvironmentJobHCL)
 		assert.False(t, exited)
 		assert.NotNil(t, job)
 	})

environment/template-environment-job.hcl

@@ -1,6 +1,6 @@
 // This is the default job configuration that is used when no path to another default configuration is given
 
-job "0-default" {
+job "template-0" {
   datacenters = ["dc1"]
   type = "batch"
 

go.sum

@@ -609,8 +609,6 @@ github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+
 github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.2.0 h1:Hbg2NidpLE8veEBkEZTL3CvlkUIVzuU9jDplZO54c48=
 github.com/stretchr/objx v0.2.0/go.mod h1:qt09Ya8vawLte6SNmTgCsAVtYtaKzEcn8ATUoHMkEqE=
-github.com/stretchr/objx v0.3.0 h1:NGXK3lHquSN08v5vWalVI/L8XU9hdzE/G6xsrze47As=
-github.com/stretchr/objx v0.3.0/go.mod h1:qt09Ya8vawLte6SNmTgCsAVtYtaKzEcn8ATUoHMkEqE=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=

main.go

@@ -47,10 +47,7 @@ func initServer() *http.Server {
 	}
 
 	runnerManager := runner.NewNomadRunnerManager(nomadAPIClient, context.Background())
-	environmentManager, err := environment.NewNomadEnvironmentManager(runnerManager, nomadAPIClient)
+	environmentManager := environment.NewNomadEnvironmentManager(runnerManager, nomadAPIClient)
-	if err != nil {
-		log.WithError(err).Fatal("Error creating new Nomad environment manager")
-	}
 
 	return &http.Server{
 		Addr:         config.Config.PoseidonAPIURL().Host,

nomad/executor_api_mock.go

@@ -142,52 +142,6 @@ func (_m *ExecutorAPIMock) JobScale(jobId string) (uint, error) {
 	return r0, r1
 }
 
-// LoadAllJobs provides a mock function with given fields:
-func (_m *ExecutorAPIMock) LoadAllJobs() ([]*api.Job, error) {
-	ret := _m.Called()
-
-	var r0 []*api.Job
-	if rf, ok := ret.Get(0).(func() []*api.Job); ok {
-		r0 = rf()
-	} else {
-		if ret.Get(0) != nil {
-			r0 = ret.Get(0).([]*api.Job)
-		}
-	}
-
-	var r1 error
-	if rf, ok := ret.Get(1).(func() error); ok {
-		r1 = rf()
-	} else {
-		r1 = ret.Error(1)
-	}
-
-	return r0, r1
-}
-
-// LoadEnvironmentTemplate provides a mock function with given fields: environmentID
-func (_m *ExecutorAPIMock) LoadEnvironmentTemplate(environmentID string) (*api.Job, error) {
-	ret := _m.Called(environmentID)
-
-	var r0 *api.Job
-	if rf, ok := ret.Get(0).(func(string) *api.Job); ok {
-		r0 = rf(environmentID)
-	} else {
-		if ret.Get(0) != nil {
-			r0 = ret.Get(0).(*api.Job)
-		}
-	}
-
-	var r1 error
-	if rf, ok := ret.Get(1).(func(string) error); ok {
-		r1 = rf(environmentID)
-	} else {
-		r1 = ret.Error(1)
-	}
-
-	return r0, r1
-}
-
 // LoadJobList provides a mock function with given fields:
 func (_m *ExecutorAPIMock) LoadJobList() ([]*api.JobListStub, error) {
 	ret := _m.Called()
@@ -211,8 +165,31 @@ func (_m *ExecutorAPIMock) LoadJobList() ([]*api.JobListStub, error) {
 	return r0, r1
 }
 
+// LoadRunnerJobs provides a mock function with given fields: environmentID
+func (_m *ExecutorAPIMock) LoadRunnerJobs(environmentID string) ([]*api.Job, error) {
+	ret := _m.Called(environmentID)
+
+	var r0 []*api.Job
+	if rf, ok := ret.Get(0).(func(string) []*api.Job); ok {
+		r0 = rf(environmentID)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).([]*api.Job)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(string) error); ok {
+		r1 = rf(environmentID)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
 // LoadRunners provides a mock function with given fields: jobID
-func (_m *ExecutorAPIMock) LoadRunners(jobID string) ([]string, error) {
+func (_m *ExecutorAPIMock) LoadRunnerIDs(jobID string) ([]string, error) {
 	ret := _m.Called(jobID)
 
 	var r0 []string
@@ -257,6 +234,29 @@ func (_m *ExecutorAPIMock) LoadEnvironmentTemplate(environmentID string) (*api.J
 	return r0, r1
 }
 
+// LoadTemplateJobs provides a mock function with given fields:
+func (_m *ExecutorAPIMock) LoadEnvironmentJobs() ([]*api.Job, error) {
+	ret := _m.Called()
+
+	var r0 []*api.Job
+	if rf, ok := ret.Get(0).(func() []*api.Job); ok {
+		r0 = rf()
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).([]*api.Job)
+		}
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func() error); ok {
+		r1 = rf()
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
 // MarkRunnerAsUsed provides a mock function with given fields: runnerID
 func (_m *ExecutorAPIMock) MarkRunnerAsUsed(runnerID string) error {
 	ret := _m.Called(runnerID)
@@ -306,13 +306,27 @@ func (_m *ExecutorAPIMock) RegisterNomadJob(job *api.Job) (string, error) {
 	return r0, r1
 }
 
-// RegisterTemplateJob provides a mock function with given fields: defaultJob, environmentID, prewarmingPoolSize, cpuLimit, memoryLimit, image, networkAccess, exposedPorts
+// RegisterRunnerJob provides a mock function with given fields: template
-func (_m *ExecutorAPIMock) RegisterTemplateJob(defaultJob *api.Job, environmentID int, prewarmingPoolSize uint, cpuLimit uint, memoryLimit uint, image string, networkAccess bool, exposedPorts []uint16) (*api.Job, error) {
+func (_m *ExecutorAPIMock) RegisterRunnerJob(template *api.Job) error {
-	ret := _m.Called(defaultJob, environmentID, prewarmingPoolSize, cpuLimit, memoryLimit, image, networkAccess, exposedPorts)
+	ret := _m.Called(template)
+
+	var r0 error
+	if rf, ok := ret.Get(0).(func(*api.Job) error); ok {
+		r0 = rf(template)
+	} else {
+		r0 = ret.Error(0)
+	}
+
+	return r0
+}
+
+// RegisterTemplateJob provides a mock function with given fields: defaultJob, id, prewarmingPoolSize, cpuLimit, memoryLimit, image, networkAccess, exposedPorts
+func (_m *ExecutorAPIMock) RegisterTemplateJob(defaultJob *api.Job, id string, prewarmingPoolSize uint, cpuLimit uint, memoryLimit uint, image string, networkAccess bool, exposedPorts []uint16) (*api.Job, error) {
+	ret := _m.Called(defaultJob, id, prewarmingPoolSize, cpuLimit, memoryLimit, image, networkAccess, exposedPorts)
 
 	var r0 *api.Job
-	if rf, ok := ret.Get(0).(func(*api.Job, int, uint, uint, uint, string, bool, []uint16) *api.Job); ok {
+	if rf, ok := ret.Get(0).(func(*api.Job, string, uint, uint, uint, string, bool, []uint16) *api.Job); ok {
-		r0 = rf(defaultJob, environmentID, prewarmingPoolSize, cpuLimit, memoryLimit, image, networkAccess, exposedPorts)
+		r0 = rf(defaultJob, id, prewarmingPoolSize, cpuLimit, memoryLimit, image, networkAccess, exposedPorts)
 	} else {
 		if ret.Get(0) != nil {
 			r0 = ret.Get(0).(*api.Job)
@@ -320,8 +334,8 @@ func (_m *ExecutorAPIMock) RegisterTemplateJob(defaultJob *api.Job, environmentI
 	}
 
 	var r1 error
-	if rf, ok := ret.Get(1).(func(*api.Job, int, uint, uint, uint, string, bool, []uint16) error); ok {
+	if rf, ok := ret.Get(1).(func(*api.Job, string, uint, uint, uint, string, bool, []uint16) error); ok {
-		r1 = rf(defaultJob, environmentID, prewarmingPoolSize, cpuLimit, memoryLimit, image, networkAccess, exposedPorts)
+		r1 = rf(defaultJob, id, prewarmingPoolSize, cpuLimit, memoryLimit, image, networkAccess, exposedPorts)
 	} else {
 		r1 = ret.Error(1)
 	}

nomad/job.go

@@ -6,18 +6,17 @@ import (
 	"fmt"
 	nomadApi "github.com/hashicorp/nomad/api"
 	"strconv"
-	"strings"
 )
 
 const (
 	TaskGroupName            = "default-group"
 	TaskName                 = "default-task"
+	TemplateJobPrefix        = "template"
 	ConfigTaskGroupName      = "config"
 	DummyTaskName            = "dummy"
-	defaultRunnerJobID       = "default"
 	DefaultTaskDriver        = "docker"
 	DefaultDummyTaskDriver   = "exec"
-	DefaultTaskCommand       = "true"
+	DefaultDummyTaskCommand  = "true"
 	ConfigMetaEnvironmentKey = "environment"
 	ConfigMetaUsedKey        = "used"
 	ConfigMetaUsedValue      = "true"
@@ -26,39 +25,9 @@ const (
 )
 
 var (
-	ErrorInvalidJobID            = errors.New("invalid job id")
 	ErrorConfigTaskGroupNotFound = errors.New("config task group not found in job")
 )
 
-// RunnerJobID creates the job id. This requires an environment id and a runner id.
-func RunnerJobID(environmentID, runnerID string) string {
-	return fmt.Sprintf("%s-%s", environmentID, runnerID)
-}
-
-// EnvironmentIDFromJobID returns the environment id that is part of the passed job id.
-func EnvironmentIDFromJobID(jobID string) (int, error) {
-	parts := strings.Split(jobID, "-")
-	if len(parts) == 0 {
-		return 0, fmt.Errorf("empty job id: %w", ErrorInvalidJobID)
-	}
-	environmentID, err := strconv.Atoi(parts[0])
-	if err != nil {
-		return 0, fmt.Errorf("invalid environment id par %v: %w", err, ErrorInvalidJobID)
-	}
-	return environmentID, nil
-}
-
-// TemplateJobID creates the environment specific id of the template job.
-func TemplateJobID(id string) string {
-	return RunnerJobID(id, defaultRunnerJobID)
-}
-
-// IsEnvironmentTemplateID checks if the passed job id belongs to a template job.
-func IsEnvironmentTemplateID(jobID string) bool {
-	parts := strings.Split(jobID, "-")
-	return len(parts) == 2 && parts[1] == defaultRunnerJobID
-}
-
 // FindConfigTaskGroup returns the config task group of a job.
 // The config task group should be included in all jobs.
 func FindConfigTaskGroup(job *nomadApi.Job) *nomadApi.TaskGroup {
@@ -82,13 +51,13 @@ func SetMetaConfigValue(job *nomadApi.Job, key, value string) error {
 // RegisterTemplateJob creates a Nomad job based on the default job configuration and the given parameters.
 // It registers the job with Nomad and waits until the registration completes.
 func (a *APIClient) RegisterTemplateJob(
-	defaultJob *nomadApi.Job,
+	basisJob *nomadApi.Job,
-	environmentID int,
+	id string,
 	prewarmingPoolSize, cpuLimit, memoryLimit uint,
 	image string,
 	networkAccess bool,
 	exposedPorts []uint16) (*nomadApi.Job, error) {
-	job := CreateTemplateJob(defaultJob, environmentID, prewarmingPoolSize,
+	job := CreateTemplateJob(basisJob, id, prewarmingPoolSize,
 		cpuLimit, memoryLimit, image, networkAccess, exposedPorts)
 	evalID, err := a.apiQuerier.RegisterNomadJob(job)
 	if err != nil {
@@ -100,24 +69,33 @@ func (a *APIClient) RegisterTemplateJob(
 // CreateTemplateJob creates a Nomad job based on the default job configuration and the given parameters.
 // It registers the job with Nomad and waits until the registration completes.
 func CreateTemplateJob(
-	defaultJob *nomadApi.Job,
+	basisJob *nomadApi.Job,
-	environmentID int,
+	id string,
 	prewarmingPoolSize, cpuLimit, memoryLimit uint,
 	image string,
 	networkAccess bool,
 	exposedPorts []uint16) *nomadApi.Job {
-	job := *defaultJob
+	job := *basisJob
-	templateJobID := TemplateJobID(strconv.Itoa(environmentID))
+	job.ID = &id
-	job.ID = &templateJobID
+	job.Name = &id
-	job.Name = &templateJobID
 
 	var taskGroup = createTaskGroup(&job, TaskGroupName, prewarmingPoolSize)
 	configureTask(taskGroup, TaskName, cpuLimit, memoryLimit, image, networkAccess, exposedPorts)
-	storeConfiguration(&job, environmentID, prewarmingPoolSize)
+	storeTemplateConfiguration(&job, prewarmingPoolSize)
 
 	return &job
 }
 
+func (a *APIClient) RegisterRunnerJob(template *nomadApi.Job) error {
+	storeRunnerConfiguration(template)
+
+	evalID, err := a.apiQuerier.RegisterNomadJob(template)
+	if err != nil {
+		return fmt.Errorf("couldn't register runner job: %w", err)
+	}
+	return a.MonitorEvaluation(evalID, context.Background())
+}
+
 func createTaskGroup(job *nomadApi.Job, name string, prewarmingPoolSize uint) *nomadApi.TaskGroup {
 	var taskGroup *nomadApi.TaskGroup
 	if len(job.TaskGroups) == 0 {
@@ -207,17 +185,20 @@ func configureTask(
 	configureNetwork(taskGroup, networkAccess, exposedPorts)
 }
 
-func storeConfiguration(job *nomadApi.Job, id int, prewarmingPoolSize uint) {
+func storeTemplateConfiguration(job *nomadApi.Job, prewarmingPoolSize uint) {
 	taskGroup := findOrCreateConfigTaskGroup(job)
 
-	if taskGroup.Meta == nil {
+	taskGroup.Meta = make(map[string]string)
-		taskGroup.Meta = make(map[string]string)
-	}
-	taskGroup.Meta[ConfigMetaEnvironmentKey] = strconv.Itoa(id)
-	taskGroup.Meta[ConfigMetaUsedKey] = ConfigMetaUnusedValue
 	taskGroup.Meta[ConfigMetaPoolSizeKey] = strconv.Itoa(int(prewarmingPoolSize))
 }
 
+func storeRunnerConfiguration(job *nomadApi.Job) {
+	taskGroup := findOrCreateConfigTaskGroup(job)
+
+	taskGroup.Meta = make(map[string]string)
+	taskGroup.Meta[ConfigMetaUsedKey] = ConfigMetaUnusedValue
+}
+
 func findOrCreateConfigTaskGroup(job *nomadApi.Job) *nomadApi.TaskGroup {
 	taskGroup := FindConfigTaskGroup(job)
 	if taskGroup == nil {
@@ -245,5 +226,5 @@ func createDummyTaskIfNotPresent(taskGroup *nomadApi.TaskGroup) {
 	if task.Config == nil {
 		task.Config = make(map[string]interface{})
 	}
-	task.Config["command"] = DefaultTaskCommand
+	task.Config["command"] = DefaultDummyTaskCommand
 }

nomad/job_test.go

@@ -27,7 +27,7 @@ func createTestResources() *nomadApi.Resources {
 }
 
 func createTestJob() (job, base *nomadApi.Job) {
-	jobID := TemplateJobID(tests.DefaultEnvironmentIDAsString)
+	jobID := tests.DefaultJobID
 	base = nomadApi.NewBatchJob(jobID, jobID, "region-name", 100)
 	job = nomadApi.NewBatchJob(jobID, jobID, "region-name", 100)
 	task := createTestTask()
@@ -221,11 +221,9 @@ func TestConfigureTaskWhenTaskExists(t *testing.T) {
 
 func TestCreateTemplateJobSetsAllGivenArguments(t *testing.T) {
 	testJob, base := createTestJob()
-	testJobEnvironmentID, err := EnvironmentIDFromJobID(*testJob.ID)
-	assert.NoError(t, err)
 	job := CreateTemplateJob(
 		base,
-		testJobEnvironmentID,
+		tests.DefaultJobID,
 		uint(*testJob.TaskGroups[0].Count),
 		uint(*testJob.TaskGroups[0].Tasks[0].Resources.CPU),
 		uint(*testJob.TaskGroups[0].Tasks[0].Resources.MemoryMB),
@@ -244,7 +242,7 @@ func TestRegisterTemplateJobFailsWhenNomadJobRegistrationFails(t *testing.T) {
 
 	apiClient := &APIClient{&apiMock}
 
-	_, err := apiClient.RegisterTemplateJob(&nomadApi.Job{}, tests.DefaultEnvironmentIDAsInteger,
+	_, err := apiClient.RegisterTemplateJob(&nomadApi.Job{}, tests.DefaultJobID,
 		1, 2, 3, "image", false, []uint16{})
 	assert.ErrorIs(t, err, expectedErr)
 	apiMock.AssertNotCalled(t, "EvaluationStream")
@@ -267,7 +265,7 @@ func TestRegisterTemplateJobSucceedsWhenMonitoringEvaluationSucceeds(t *testing.
 
 	apiClient := &APIClient{&apiMock}
 
-	_, err := apiClient.RegisterTemplateJob(&nomadApi.Job{}, tests.DefaultEnvironmentIDAsInteger,
+	_, err := apiClient.RegisterTemplateJob(&nomadApi.Job{}, tests.DefaultJobID,
 		1, 2, 3, "image", false, []uint16{})
 	assert.NoError(t, err)
 }
@@ -281,7 +279,7 @@ func TestRegisterTemplateJobReturnsErrorWhenMonitoringEvaluationFails(t *testing
 
 	apiClient := &APIClient{&apiMock}
 
-	_, err := apiClient.RegisterTemplateJob(&nomadApi.Job{}, tests.DefaultEnvironmentIDAsInteger,
+	_, err := apiClient.RegisterTemplateJob(&nomadApi.Job{}, tests.DefaultJobID,
 		1, 2, 3, "image", false, []uint16{})
 	assert.ErrorIs(t, err, tests.ErrDefault)
 }

nomad/nomad.go

@@ -18,6 +18,7 @@ var (
 	ErrorExecutorCommunicationFailed = errors.New("communication with executor failed")
 	ErrorEvaluation                  = errors.New("evaluation could not complete")
 	ErrorPlacingAllocations          = errors.New("failed to place all allocations")
+	ErrorLoadingJob                  = errors.New("failed to load job")
 )
 
 type AllocationProcessor func(*nomadApi.Allocation)
@@ -26,21 +27,25 @@ type AllocationProcessor func(*nomadApi.Allocation)
 type ExecutorAPI interface {
 	apiQuerier
 
-	// LoadAllJobs loads all existing jobs independent of the environment or if it is a template job.
+	// LoadEnvironmentJobs loads all environment jobs.
-	LoadAllJobs() ([]*nomadApi.Job, error)
+	LoadEnvironmentJobs() ([]*nomadApi.Job, error)
 
-	// LoadRunners loads all runners of the specified environment which are running and not about to get stopped.
+	// LoadRunnerJobs loads all runner jobs specific for the environment.
-	LoadRunners(environmentID string) (runnerIds []string, err error)
+	LoadRunnerJobs(environmentID string) ([]*nomadApi.Job, error)
+
+	// LoadRunnerIDs returns the IDs of all runners of the specified environment which are running and not about to
+	// get stopped.
+	LoadRunnerIDs(environmentID string) (runnerIds []string, err error)
 
 	// RegisterTemplateJob creates a template job based on the default job configuration and the given parameters.
 	// It registers the job and waits until the registration completes.
-	RegisterTemplateJob(defaultJob *nomadApi.Job, environmentID int,
+	RegisterTemplateJob(defaultJob *nomadApi.Job, id string,
 		prewarmingPoolSize, cpuLimit, memoryLimit uint,
 		image string, networkAccess bool, exposedPorts []uint16) (*nomadApi.Job, error)
 
-	// LoadEnvironmentTemplate loads the template job of the specified environment.
+	// RegisterRunnerJob creates a runner job based on the template job.
-	// Based on the template job new runners can be created.
+	// It registers the job and waits until the registration completes.
-	LoadEnvironmentTemplate(environmentID string) (*nomadApi.Job, error)
+	RegisterRunnerJob(template *nomadApi.Job) error
 
 	// MonitorEvaluation monitors the given evaluation ID.
 	// It waits until the evaluation reaches one of the states complete, canceled or failed.
@@ -81,7 +86,7 @@ func (a *APIClient) init(nomadURL *url.URL, nomadNamespace string) error {
 	return a.apiQuerier.init(nomadURL, nomadNamespace)
 }
 
-func (a *APIClient) LoadRunners(environmentID string) (runnerIDs []string, err error) {
+func (a *APIClient) LoadRunnerIDs(environmentID string) (runnerIDs []string, err error) {
 	list, err := a.listJobs(environmentID)
 	if err != nil {
 		return nil, err
@@ -95,12 +100,26 @@ func (a *APIClient) LoadRunners(environmentID string) (runnerIDs []string, err e
 	return runnerIDs, nil
 }
 
-func (a *APIClient) LoadEnvironmentTemplate(environmentID string) (*nomadApi.Job, error) {
+func (a *APIClient) LoadRunnerJobs(environmentID string) ([]*nomadApi.Job, error) {
-	job, err := a.job(TemplateJobID(environmentID))
+	runnerIDs, err := a.LoadRunnerIDs(environmentID)
 	if err != nil {
-		return nil, fmt.Errorf("failed loading template job: %w", err)
+		return []*nomadApi.Job{}, fmt.Errorf("couldn't load jobs: %w", err)
 	}
-	return job, nil
+
+	var occurredError error
+	jobs := make([]*nomadApi.Job, 0, len(runnerIDs))
+	for _, id := range runnerIDs {
+		job, err := a.apiQuerier.job(id)
+		if err != nil {
+			if occurredError == nil {
+				occurredError = ErrorLoadingJob
+			}
+			occurredError = fmt.Errorf("%w: couldn't load job info for runner %s - %v", occurredError, id, err)
+			continue
+		}
+		jobs = append(jobs, job)
+	}
+	return jobs, occurredError
 }
 
 func (a *APIClient) MonitorEvaluation(evaluationID string, ctx context.Context) error {
@@ -251,8 +270,8 @@ func (a *APIClient) MarkRunnerAsUsed(runnerID string) error {
 	return nil
 }
 
-func (a *APIClient) LoadAllJobs() ([]*nomadApi.Job, error) {
+func (a *APIClient) LoadEnvironmentJobs() ([]*nomadApi.Job, error) {
-	jobStubs, err := a.LoadJobList()
+	jobStubs, err := a.listJobs(TemplateJobPrefix)
 	if err != nil {
 		return []*nomadApi.Job{}, fmt.Errorf("couldn't load jobs: %w", err)
 	}

nomad/nomad_test.go

@@ -64,7 +64,7 @@ func (s *LoadRunnersTestSuite) TestErrorOfUnderlyingApiCallIsPropagated() {
 	s.mock.On("listJobs", mock.AnythingOfType("string")).
 		Return(nil, tests.ErrDefault)
 
-	returnedIds, err := s.nomadApiClient.LoadRunners(s.jobId)
+	returnedIds, err := s.nomadApiClient.LoadRunnerIDs(s.jobId)
 	s.Nil(returnedIds)
 	s.Equal(tests.ErrDefault, err)
 }
@@ -73,7 +73,7 @@ func (s *LoadRunnersTestSuite) TestReturnsNoErrorWhenUnderlyingApiCallDoesNot()
 	s.mock.On("listJobs", mock.AnythingOfType("string")).
 		Return([]*nomadApi.JobListStub{}, nil)
 
-	_, err := s.nomadApiClient.LoadRunners(s.jobId)
+	_, err := s.nomadApiClient.LoadRunnerIDs(s.jobId)
 	s.NoError(err)
 }
 
@@ -81,7 +81,7 @@ func (s *LoadRunnersTestSuite) TestAvailableRunnerIsReturned() {
 	s.mock.On("listJobs", mock.AnythingOfType("string")).
 		Return([]*nomadApi.JobListStub{s.availableRunner}, nil)
 
-	returnedIds, _ := s.nomadApiClient.LoadRunners(s.jobId)
+	returnedIds, _ := s.nomadApiClient.LoadRunnerIDs(s.jobId)
 	s.Len(returnedIds, 1)
 	s.Equal(s.availableRunner.ID, returnedIds[0])
 }
@@ -90,7 +90,7 @@ func (s *LoadRunnersTestSuite) TestPendingRunnerIsNotReturned() {
 	s.mock.On("listJobs", mock.AnythingOfType("string")).
 		Return([]*nomadApi.JobListStub{s.pendingRunner}, nil)
 
-	returnedIds, _ := s.nomadApiClient.LoadRunners(s.jobId)
+	returnedIds, _ := s.nomadApiClient.LoadRunnerIDs(s.jobId)
 	s.Empty(returnedIds)
 }
 
@@ -98,7 +98,7 @@ func (s *LoadRunnersTestSuite) TestDeadRunnerIsNotReturned() {
 	s.mock.On("listJobs", mock.AnythingOfType("string")).
 		Return([]*nomadApi.JobListStub{s.deadRunner}, nil)
 
-	returnedIds, _ := s.nomadApiClient.LoadRunners(s.jobId)
+	returnedIds, _ := s.nomadApiClient.LoadRunnerIDs(s.jobId)
 	s.Empty(returnedIds)
 }
 
@@ -112,7 +112,7 @@ func (s *LoadRunnersTestSuite) TestReturnsAllAvailableRunners() {
 	s.mock.On("listJobs", mock.AnythingOfType("string")).
 		Return(runnersList, nil)
 
-	returnedIds, _ := s.nomadApiClient.LoadRunners(s.jobId)
+	returnedIds, _ := s.nomadApiClient.LoadRunnerIDs(s.jobId)
 	s.Len(returnedIds, 2)
 	s.Contains(returnedIds, s.availableRunner.ID)
 	s.Contains(returnedIds, s.anotherAvailableRunner.ID)

runner/manager.go

@@ -14,10 +14,12 @@ import (
 )
 
 var (
-	log                            = logging.GetLogger("runner")
+	log                               = logging.GetLogger("runner")
-	ErrUnknownExecutionEnvironment = errors.New("execution environment not found")
+	ErrUnknownExecutionEnvironment    = errors.New("execution environment not found")
-	ErrNoRunnersAvailable          = errors.New("no runners available for this execution environment")
+	ErrNoRunnersAvailable             = errors.New("no runners available for this execution environment")
-	ErrRunnerNotFound              = errors.New("no runner found with this id")
+	ErrRunnerNotFound                 = errors.New("no runner found with this id")
+	ErrorUpdatingExecutionEnvironment = errors.New("errors occurred when updating environment")
+	ErrorInvalidJobID                 = errors.New("invalid job id")
 )
 
 type EnvironmentID int
@@ -38,7 +40,9 @@ type NomadJobID string
 type Manager interface {
 	// CreateOrUpdateEnvironment creates the given environment if it does not exist. Otherwise, it updates
 	// the existing environment and all runners. Iff a new Environment has been created, it returns true.
-	CreateOrUpdateEnvironment(id EnvironmentID, desiredIdleRunnersCount uint, teplateJob *nomadApi.Job) (bool, error)
+	// Iff scale is true, runners are created until the desiredIdleRunnersCount is reached.
+	CreateOrUpdateEnvironment(id EnvironmentID, desiredIdleRunnersCount uint, templateJob *nomadApi.Job,
+		scale bool) (bool, error)
 
 	// Claim returns a new runner.
 	// It makes sure that the runner is not in use yet and returns an error if no runner could be provided.
@@ -55,13 +59,9 @@ type Manager interface {
 	// ScaleAllEnvironments checks for all environments if enough runners are created.
 	ScaleAllEnvironments() error
 
-	// RecoverEnvironment adds a recovered Environment to the internal structure.
+	// Load fetches all already created runners from the executor and registers them.
-	// This is intended to recover environments after a restart.
+	// It should be called during the startup process (e.g. on creation of the Manager).
-	RecoverEnvironment(id EnvironmentID, templateJob *nomadApi.Job, desiredIdleRunnersCount uint)
+	Load()
-
-	// RecoverRunner adds a recovered runner to the internal structure.
-	// This is intended to recover runners after a restart.
-	RecoverRunner(id EnvironmentID, job *nomadApi.Job, isUsed bool)
 }
 
 type NomadRunnerManager struct {
@@ -79,7 +79,7 @@ func NewNomadRunnerManager(apiClient nomad.ExecutorAPI, ctx context.Context) *No
 		NewLocalNomadEnvironmentStorage(),
 		NewLocalRunnerStorage(),
 	}
-	go m.updateRunners(ctx)
+	go m.keepRunnersSynced(ctx)
 	return m
 }
 
@@ -94,31 +94,36 @@ func (j *NomadEnvironment) ID() EnvironmentID {
 	return j.environmentID
 }
 
-func (m *NomadRunnerManager) CreateOrUpdateEnvironment(id EnvironmentID, desiredIdleRunnersCount uint, templateJob *nomadApi.Job) (bool, error) {
+func (m *NomadRunnerManager) CreateOrUpdateEnvironment(id EnvironmentID, desiredIdleRunnersCount uint,
+	templateJob *nomadApi.Job, scale bool) (bool, error) {
 	_, ok := m.environments.Get(id)
 	if !ok {
-		return true, m.registerEnvironment(id, desiredIdleRunnersCount, templateJob)
+		return true, m.registerEnvironment(id, desiredIdleRunnersCount, templateJob, scale)
 	}
-	return false, m.updateEnvironment(id, desiredIdleRunnersCount, templateJob)
+	return false, m.updateEnvironment(id, desiredIdleRunnersCount, templateJob, scale)
 }
 
-func (m *NomadRunnerManager) registerEnvironment(environmentID EnvironmentID, desiredIdleRunnersCount uint, templateJob *nomadApi.Job) error {
+func (m *NomadRunnerManager) registerEnvironment(environmentID EnvironmentID, desiredIdleRunnersCount uint,
+	templateJob *nomadApi.Job, scale bool) error {
 	m.environments.Add(&NomadEnvironment{
 		environmentID,
 		NewLocalRunnerStorage(),
 		desiredIdleRunnersCount,
 		templateJob,
 	})
-	err := m.scaleEnvironment(environmentID)
+	if scale {
-	if err != nil {
+		err := m.scaleEnvironment(environmentID)
-		return fmt.Errorf("couldn't upscale environment %w", err)
+		if err != nil {
+			return fmt.Errorf("couldn't upscale environment %w", err)
+		}
 	}
 	return nil
 }
 
 // updateEnvironment updates all runners of the specified environment. This is required as attributes like the
 // CPULimit or MemoryMB could be changed in the new template job.
-func (m *NomadRunnerManager) updateEnvironment(id EnvironmentID, desiredIdleRunnersCount uint, newTemplateJob *nomadApi.Job) error {
+func (m *NomadRunnerManager) updateEnvironment(id EnvironmentID, desiredIdleRunnersCount uint,
+	newTemplateJob *nomadApi.Job, scale bool) error {
 	environment, ok := m.environments.Get(id)
 	if !ok {
 		return ErrUnknownExecutionEnvironment
@@ -135,31 +140,34 @@ func (m *NomadRunnerManager) updateEnvironment(id EnvironmentID, desiredIdleRunn
 		return err
 	}
 
-	return m.scaleEnvironment(id)
+	if scale {
+		err = m.scaleEnvironment(id)
+	}
+	return err
 }
 
 func (m *NomadRunnerManager) updateRunnerSpecs(environmentID EnvironmentID, templateJob *nomadApi.Job) error {
-	runners, err := m.apiClient.LoadRunners(environmentID.toString())
+	runners, err := m.apiClient.LoadRunnerIDs(environmentID.toString())
 	if err != nil {
 		return fmt.Errorf("update environment couldn't load runners: %w", err)
 	}
-	var occurredErrors []string
+
+	var occurredError error
 	for _, id := range runners {
 		// avoid taking the address of the loop variable
 		runnerID := id
 		updatedRunnerJob := *templateJob
 		updatedRunnerJob.ID = &runnerID
 		updatedRunnerJob.Name = &runnerID
-		_, err := m.apiClient.RegisterNomadJob(&updatedRunnerJob)
+		err := m.apiClient.RegisterRunnerJob(&updatedRunnerJob)
 		if err != nil {
-			occurredErrors = append(occurredErrors, err.Error())
+			if occurredError == nil {
+				occurredError = ErrorUpdatingExecutionEnvironment
+			}
+			occurredError = fmt.Errorf("%w; new api error for runner %s - %v", occurredError, id, err)
 		}
 	}
-	if len(occurredErrors) > 0 {
+	return occurredError
-		errorResult := strings.Join(occurredErrors, "\n")
-		return fmt.Errorf("%d errors occurred when updating environment: %s", len(occurredErrors), errorResult)
-	}
-	return nil
 }
 
 func (m *NomadRunnerManager) Claim(environmentID EnvironmentID) (Runner, error) {
@@ -203,8 +211,8 @@ func (m *NomadRunnerManager) Return(r Runner) (err error) {
 }
 
 func (m *NomadRunnerManager) ScaleAllEnvironments() error {
-	for _, environmentID := range m.environments.List() {
+	for _, environment := range m.environments.List() {
-		err := m.scaleEnvironment(environmentID)
+		err := m.scaleEnvironment(environment.ID())
 		if err != nil {
 			return fmt.Errorf("can not scale up: %w", err)
 		}
@@ -212,43 +220,35 @@ func (m *NomadRunnerManager) ScaleAllEnvironments() error {
 	return nil
 }
 
-func (m *NomadRunnerManager) RecoverEnvironment(id EnvironmentID, templateJob *nomadApi.Job,
+func (m *NomadRunnerManager) Load() {
-	desiredIdleRunnersCount uint) {
+	for _, environment := range m.environments.List() {
-	_, ok := m.environments.Get(id)
+		environmentLogger := log.WithField("environmentID", environment.ID())
-	if ok {
+		runnerJobs, err := m.apiClient.LoadRunnerJobs(environment.ID().toString())
-		log.Error("Recovering existing environment.")
+		if err != nil {
-		return
+			environmentLogger.WithError(err).Warn("Error fetching the runner jobs")
-	}
+		}
-	environment := &NomadEnvironment{
+		for _, job := range runnerJobs {
-		environmentID: id,
+			configTaskGroup := nomad.FindConfigTaskGroup(job)
-		idleRunners:   NewLocalRunnerStorage(),
+			if configTaskGroup == nil {
-	}
+				environmentLogger.Infof("Couldn't find config task group in job %s, skipping ...", *job.ID)
-	m.environments.Add(environment)
+				continue
-	log.WithField("environmentID", environment.environmentID).Info("Added recovered environment")
+			}
-	environment.desiredIdleRunnersCount = desiredIdleRunnersCount
+			isUsed := configTaskGroup.Meta[nomad.ConfigMetaUsedKey] == nomad.ConfigMetaUsedValue
-	environment.templateJob = templateJob
+			newJob := NewNomadJob(*job.ID, m.apiClient)
-}
+			if isUsed {
-
+				m.usedRunners.Add(newJob)
-func (m *NomadRunnerManager) RecoverRunner(id EnvironmentID, job *nomadApi.Job, isUsed bool) {
+			} else {
-	environment, ok := m.environments.Get(id)
+				environment.idleRunners.Add(newJob)
-	if !ok {
+			}
-		log.Error("Environment missing. Can not recover runner")
+		}
-		return
+		err = m.scaleEnvironment(environment.ID())
-	}
+		if err != nil {
-
+			environmentLogger.Error("Couldn't scale environment")
-	log.WithField("jobID", *job.ID).
+		}
-		WithField("environmentID", environment.environmentID).
-		Info("Added idle runner")
-
-	newJob := NewNomadJob(*job.ID, m.apiClient)
-	if isUsed {
-		m.usedRunners.Add(newJob)
-	} else {
-		environment.idleRunners.Add(newJob)
 	}
 }
 
-func (m *NomadRunnerManager) updateRunners(ctx context.Context) {
+func (m *NomadRunnerManager) keepRunnersSynced(ctx context.Context) {
 	retries := 0
 	for ctx.Err() == nil {
 		err := m.apiClient.WatchAllocations(ctx, m.onAllocationAdded, m.onAllocationStopped)
@@ -261,17 +261,17 @@ func (m *NomadRunnerManager) updateRunners(ctx context.Context) {
 func (m *NomadRunnerManager) onAllocationAdded(alloc *nomadApi.Allocation) {
 	log.WithField("id", alloc.JobID).Debug("Runner started")
 
-	if nomad.IsEnvironmentTemplateID(alloc.JobID) {
+	if IsEnvironmentTemplateID(alloc.JobID) {
 		return
 	}
 
-	environmentID, err := nomad.EnvironmentIDFromJobID(alloc.JobID)
+	environmentID, err := EnvironmentIDFromJobID(alloc.JobID)
 	if err != nil {
 		log.WithError(err).Warn("Allocation could not be added")
 		return
 	}
 
-	job, ok := m.environments.Get(EnvironmentID(environmentID))
+	job, ok := m.environments.Get(environmentID)
 	if ok {
 		job.idleRunners.Add(NewNomadJob(alloc.JobID, m.apiClient))
 	}
@@ -280,14 +280,14 @@ func (m *NomadRunnerManager) onAllocationAdded(alloc *nomadApi.Allocation) {
 func (m *NomadRunnerManager) onAllocationStopped(alloc *nomadApi.Allocation) {
 	log.WithField("id", alloc.JobID).Debug("Runner stopped")
 
-	environmentID, err := nomad.EnvironmentIDFromJobID(alloc.JobID)
+	environmentID, err := EnvironmentIDFromJobID(alloc.JobID)
 	if err != nil {
 		log.WithError(err).Warn("Stopped allocation can not be handled")
 		return
 	}
 
 	m.usedRunners.Delete(alloc.JobID)
-	job, ok := m.environments.Get(EnvironmentID(environmentID))
+	job, ok := m.environments.Get(environmentID)
 	if ok {
 		job.idleRunners.Delete(alloc.JobID)
 	}
@@ -318,19 +318,40 @@ func (m *NomadRunnerManager) createRunner(environment *NomadEnvironment) error {
 	if err != nil {
 		return fmt.Errorf("failed generating runner id")
 	}
-	newRunnerID := nomad.RunnerJobID(environment.ID().toString(), newUUID.String())
+	newRunnerID := RunnerJobID(environment.ID(), newUUID.String())
 
 	template := *environment.templateJob
 	template.ID = &newRunnerID
 	template.Name = &newRunnerID
 
-	evalID, err := m.apiClient.RegisterNomadJob(&template)
+	return m.apiClient.RegisterRunnerJob(&template)
-	if err != nil {
+}
-		return fmt.Errorf("couldn't register Nomad environment: %w", err)
+
-	}
+// RunnerJobID returns the nomad job id of the runner with the given environment id and uuid.
-	err = m.apiClient.MonitorEvaluation(evalID, context.Background())
+func RunnerJobID(environmentID EnvironmentID, uuid string) string {
-	if err != nil {
+	return fmt.Sprintf("%d-%s", environmentID, uuid)
-		return fmt.Errorf("couldn't monitor evaluation: %w", err)
+}
-	}
+
-	return nil
+// EnvironmentIDFromJobID returns the environment id that is part of the passed job id.
+func EnvironmentIDFromJobID(jobID string) (EnvironmentID, error) {
+	parts := strings.Split(jobID, "-")
+	if len(parts) == 0 {
+		return 0, fmt.Errorf("empty job id: %w", ErrorInvalidJobID)
+	}
+	environmentID, err := strconv.Atoi(parts[0])
+	if err != nil {
+		return 0, fmt.Errorf("invalid environment id par %v: %w", err, ErrorInvalidJobID)
+	}
+	return EnvironmentID(environmentID), nil
+}
+
+// TemplateJobID returns the id of the template job for the environment with the given id.
+func TemplateJobID(id EnvironmentID) string {
+	return fmt.Sprintf("%s-%d", nomad.TemplateJobPrefix, id)
+}
+
+// IsEnvironmentTemplateID checks if the passed job id belongs to a template job.
+func IsEnvironmentTemplateID(jobID string) bool {
+	parts := strings.Split(jobID, "-")
+	return len(parts) == 2 && parts[0] == nomad.TemplateJobPrefix
 }

runner/manager_mock.go

@@ -35,20 +35,20 @@ func (_m *ManagerMock) Claim(id EnvironmentID) (Runner, error) {
 	return r0, r1
 }
 
-// CreateOrUpdateEnvironment provides a mock function with given fields: id, desiredIdleRunnersCount, teplateJob
+// CreateOrUpdateEnvironment provides a mock function with given fields: id, desiredIdleRunnersCount, teplateJob, scale
-func (_m *ManagerMock) CreateOrUpdateEnvironment(id EnvironmentID, desiredIdleRunnersCount uint, teplateJob *api.Job) (bool, error) {
+func (_m *ManagerMock) CreateOrUpdateEnvironment(id EnvironmentID, desiredIdleRunnersCount uint, teplateJob *api.Job, scale bool) (bool, error) {
-	ret := _m.Called(id, desiredIdleRunnersCount, teplateJob)
+	ret := _m.Called(id, desiredIdleRunnersCount, teplateJob, scale)
 
 	var r0 bool
-	if rf, ok := ret.Get(0).(func(EnvironmentID, uint, *api.Job) bool); ok {
+	if rf, ok := ret.Get(0).(func(EnvironmentID, uint, *api.Job, bool) bool); ok {
-		r0 = rf(id, desiredIdleRunnersCount, teplateJob)
+		r0 = rf(id, desiredIdleRunnersCount, teplateJob, scale)
 	} else {
 		r0 = ret.Get(0).(bool)
 	}
 
 	var r1 error
-	if rf, ok := ret.Get(1).(func(EnvironmentID, uint, *api.Job) error); ok {
+	if rf, ok := ret.Get(1).(func(EnvironmentID, uint, *api.Job, bool) error); ok {
-		r1 = rf(id, desiredIdleRunnersCount, teplateJob)
+		r1 = rf(id, desiredIdleRunnersCount, teplateJob, scale)
 	} else {
 		r1 = ret.Error(1)
 	}
@@ -79,14 +79,9 @@ func (_m *ManagerMock) Get(runnerID string) (Runner, error) {
 	return r0, r1
 }
 
-// RecoverEnvironment provides a mock function with given fields: id, templateJob, desiredIdleRunnersCount
+// Load provides a mock function with given fields:
-func (_m *ManagerMock) RecoverEnvironment(id EnvironmentID, templateJob *api.Job, desiredIdleRunnersCount uint) {
+func (_m *ManagerMock) Load() {
-	_m.Called(id, templateJob, desiredIdleRunnersCount)
+	_m.Called()
-}
-
-// RecoverRunner provides a mock function with given fields: id, environment, isUsed
-func (_m *ManagerMock) RecoverRunner(id EnvironmentID, job *api.Job, isUsed bool) {
-	_m.Called(id, job, isUsed)
 }
 
 // Return provides a mock function with given fields: r

runner/manager_test.go

@@ -49,18 +49,17 @@ func mockRunnerQueries(apiMock *nomad.ExecutorAPIMock, returnedRunnerIds []strin
 		<-time.After(10 * time.Minute) // 10 minutes is the default test timeout
 		call.ReturnArguments = mock.Arguments{nil}
 	})
-	apiMock.On("LoadAllJobs").Return([]*nomadApi.Job{}, nil)
+	apiMock.On("LoadEnvironmentJobs").Return([]*nomadApi.Job{}, nil)
 	apiMock.On("MarkRunnerAsUsed", mock.AnythingOfType("string")).Return(nil)
-	apiMock.On("LoadRunners", tests.DefaultJobID).Return(returnedRunnerIds, nil)
+	apiMock.On("LoadRunnerIDs", tests.DefaultJobID).Return(returnedRunnerIds, nil)
 	apiMock.On("JobScale", tests.DefaultJobID).Return(uint(len(returnedRunnerIds)), nil)
 	apiMock.On("SetJobScale", tests.DefaultJobID, mock.AnythingOfType("uint"), "Runner Requested").Return(nil)
-	apiMock.On("LoadEnvironmentTemplate", mock.AnythingOfType("string")).Return(&nomadApi.Job{}, nil)
+	apiMock.On("RegisterRunnerJob", mock.Anything).Return(nil)
-	apiMock.On("RegisterNomadJob", mock.Anything).Return("", nil)
 	apiMock.On("MonitorEvaluation", mock.Anything, mock.Anything).Return(nil)
 }
 
 func (s *ManagerTestSuite) registerDefaultEnvironment() {
-	err := s.nomadRunnerManager.registerEnvironment(defaultEnvironmentID, 0, &nomadApi.Job{})
+	err := s.nomadRunnerManager.registerEnvironment(defaultEnvironmentID, 0, &nomadApi.Job{}, true)
 	s.Require().NoError(err)
 }
 
@@ -74,7 +73,8 @@ func (s *ManagerTestSuite) waitForRunnerRefresh() {
 }
 
 func (s *ManagerTestSuite) TestRegisterEnvironmentAddsNewJob() {
-	err := s.nomadRunnerManager.registerEnvironment(anotherEnvironmentID, defaultDesiredRunnersCount, &nomadApi.Job{})
+	err := s.nomadRunnerManager.
+		registerEnvironment(anotherEnvironmentID, defaultDesiredRunnersCount, &nomadApi.Job{}, true)
 	s.Require().NoError(err)
 	job, ok := s.nomadRunnerManager.environments.Get(defaultEnvironmentID)
 	s.True(ok)
@@ -180,7 +180,7 @@ func (s *ManagerTestSuite) TestUpdateRunnersLogsErrorFromWatchAllocation() {
 
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	go s.nomadRunnerManager.updateRunners(ctx)
+	go s.nomadRunnerManager.keepRunnersSynced(ctx)
 	<-time.After(10 * time.Millisecond)
 
 	s.Require().Equal(1, len(hook.Entries))
@@ -208,7 +208,7 @@ func (s *ManagerTestSuite) TestUpdateRunnersAddsIdleRunner() {
 
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	go s.nomadRunnerManager.updateRunners(ctx)
+	go s.nomadRunnerManager.keepRunnersSynced(ctx)
 	<-time.After(10 * time.Millisecond)
 
 	_, ok = environment.idleRunners.Get(allocation.JobID)
@@ -235,7 +235,7 @@ func (s *ManagerTestSuite) TestUpdateRunnersRemovesIdleAndUsedRunner() {
 
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	go s.nomadRunnerManager.updateRunners(ctx)
+	go s.nomadRunnerManager.keepRunnersSynced(ctx)
 	<-time.After(10 * time.Millisecond)
 
 	_, ok = environment.idleRunners.Get(allocation.JobID)

runner/nomad_environment_storage.go

@@ -6,8 +6,8 @@ import (
 
 // NomadEnvironmentStorage is an interface for storing Nomad environments.
 type NomadEnvironmentStorage interface {
-	// List returns all keys of environments stored in this storage.
+	// List returns all environments stored in this storage.
-	List() []EnvironmentID
+	List() []*NomadEnvironment
 
 	// Add adds an environment to the storage.
 	// It overwrites the old environment if one with the same id was already stored.
@@ -39,12 +39,14 @@ func NewLocalNomadEnvironmentStorage() *localNomadEnvironmentStorage {
 	}
 }
 
-func (s *localNomadEnvironmentStorage) List() []EnvironmentID {
+func (s *localNomadEnvironmentStorage) List() []*NomadEnvironment {
-	keys := make([]EnvironmentID, 0, len(s.environments))
+	s.RLock()
-	for k := range s.environments {
+	defer s.RUnlock()
-		keys = append(keys, k)
+	values := make([]*NomadEnvironment, 0, len(s.environments))
+	for _, v := range s.environments {
+		values = append(values, v)
 	}
-	return keys
+	return values
 }
 
 func (s *localNomadEnvironmentStorage) Add(environment *NomadEnvironment) {

tests/e2e/environments_test.go

@@ -6,7 +6,7 @@ import (
 	"github.com/stretchr/testify/require"
 	"gitlab.hpi.de/codeocean/codemoon/poseidon/api"
 	"gitlab.hpi.de/codeocean/codemoon/poseidon/api/dto"
-	"gitlab.hpi.de/codeocean/codemoon/poseidon/nomad"
+	"gitlab.hpi.de/codeocean/codemoon/poseidon/runner"
 	"gitlab.hpi.de/codeocean/codemoon/poseidon/tests"
 	"gitlab.hpi.de/codeocean/codemoon/poseidon/tests/helpers"
 	"io"
@@ -46,7 +46,7 @@ func TestCreateOrUpdateEnvironment(t *testing.T) {
 
 	t.Run("updates limits in Nomad correctly", func(t *testing.T) {
 		updateRequest := request
-		updateRequest.CPULimit = 1337
+		updateRequest.CPULimit = 150
 		updateRequest.MemoryLimit = 142
 
 		assertPutReturnsStatusAndZeroContent(t, path, updateRequest, http.StatusNoContent)
@@ -103,7 +103,7 @@ func assertPutReturnsStatusAndZeroContent(t *testing.T, path string,
 
 func validateJob(t *testing.T, expected dto.ExecutionEnvironmentRequest) {
 	t.Helper()
-	job := findNomadJob(t, tests.AnotherEnvironmentIDAsString)
+	job := findTemplateJob(t, tests.AnotherEnvironmentIDAsInteger)
 
 	assertEqualValueStringPointer(t, nomadNamespace, job.Namespace)
 	assertEqualValueStringPointer(t, "batch", job.Type)
@@ -137,9 +137,9 @@ func validateJob(t *testing.T, expected dto.ExecutionEnvironmentRequest) {
 	}
 }
 
-func findNomadJob(t *testing.T, jobID string) *nomadApi.Job {
+func findTemplateJob(t *testing.T, id runner.EnvironmentID) *nomadApi.Job {
 	t.Helper()
-	job, _, err := nomadClient.Jobs().Info(nomad.TemplateJobID(jobID), nil)
+	job, _, err := nomadClient.Jobs().Info(runner.TemplateJobID(id), nil)
 	if err != nil {
 		t.Fatalf("Error retrieving Nomad job: %v", err)
 	}

tests/e2e/websocket_test.go

@@ -170,7 +170,10 @@ func (s *E2ETestSuite) TestStderrFifoIsRemoved() {
 }
 
 func (s *E2ETestSuite) ListTempDirectory(runnerID string) string {
-	alloc, _, err := nomadClient.Allocations().Info(runnerID, nil)
+	allocListStub, _, err := nomadClient.Jobs().Allocations(runnerID, true, nil)
+	s.Require().NoError(err)
+	s.Require().Equal(1, len(allocListStub))
+	alloc, _, err := nomadClient.Allocations().Info(allocListStub[0].ID, nil)
 	s.Require().NoError(err)
 
 	var stdout, stderr bytes.Buffer