Restructure project

We previously didn't really had any structure in our project apart
from creating a new folder for each package in our project root.
Now that we have accumulated some packages, we use the well-known
Golang project layout in order to clearly communicate our intent
with packages. See https://github.com/golang-standards/project-layout

internal/environment/manager_test.go

@@ -0,0 +1,142 @@
+package environment
+
+import (
+	nomadApi "github.com/hashicorp/nomad/api"
+	"github.com/sirupsen/logrus"
+	"github.com/sirupsen/logrus/hooks/test"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/suite"
+	"gitlab.hpi.de/codeocean/codemoon/poseidon/internal/nomad"
+	"gitlab.hpi.de/codeocean/codemoon/poseidon/internal/runner"
+	"gitlab.hpi.de/codeocean/codemoon/poseidon/pkg/dto"
+	"gitlab.hpi.de/codeocean/codemoon/poseidon/tests"
+	"testing"
+)
+
+type CreateOrUpdateTestSuite struct {
+	suite.Suite
+	runnerManagerMock runner.ManagerMock
+	apiMock           nomad.ExecutorAPIMock
+	request           dto.ExecutionEnvironmentRequest
+	manager           *NomadEnvironmentManager
+	environmentID     runner.EnvironmentID
+}
+
+func TestCreateOrUpdateTestSuite(t *testing.T) {
+	suite.Run(t, new(CreateOrUpdateTestSuite))
+}
+
+func (s *CreateOrUpdateTestSuite) SetupTest() {
+	s.runnerManagerMock = runner.ManagerMock{}
+
+	s.apiMock = nomad.ExecutorAPIMock{}
+	s.request = dto.ExecutionEnvironmentRequest{
+		PrewarmingPoolSize: 10,
+		CPULimit:           20,
+		MemoryLimit:        30,
+		Image:              "my-image",
+		NetworkAccess:      false,
+		ExposedPorts:       nil,
+	}
+
+	s.manager = &NomadEnvironmentManager{
+		runnerManager: &s.runnerManagerMock,
+		api:           &s.apiMock,
+	}
+
+	s.environmentID = runner.EnvironmentID(tests.DefaultEnvironmentIDAsInteger)
+}
+
+func (s *CreateOrUpdateTestSuite) mockRegisterTemplateJob(job *nomadApi.Job, err error) {
+	s.apiMock.On("RegisterTemplateJob",
+		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", mock.AnythingOfType("EnvironmentID"),
+		mock.AnythingOfType("uint"), mock.AnythingOfType("*api.Job"), mock.AnythingOfType("bool")).
+		Return(created, err)
+}
+
+func (s *CreateOrUpdateTestSuite) TestRegistersCorrectTemplateJob() {
+	s.mockRegisterTemplateJob(&nomadApi.Job{}, nil)
+	s.mockCreateOrUpdateEnvironment(true, nil)
+
+	_, err := s.manager.CreateOrUpdate(s.environmentID, s.request)
+	s.NoError(err)
+
+	s.apiMock.AssertCalled(s.T(), "RegisterTemplateJob",
+		&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)
+}
+
+func (s *CreateOrUpdateTestSuite) TestReturnsErrorWhenRegisterTemplateJobReturnsError() {
+	s.mockRegisterTemplateJob(nil, tests.ErrDefault)
+
+	created, err := s.manager.CreateOrUpdate(s.environmentID, s.request)
+	s.ErrorIs(err, tests.ErrDefault)
+	s.False(created)
+}
+
+func (s *CreateOrUpdateTestSuite) TestCreatesOrUpdatesCorrectEnvironment() {
+	templateJobID := tests.DefaultJobID
+	templateJob := &nomadApi.Job{ID: &templateJobID}
+	s.mockRegisterTemplateJob(templateJob, nil)
+	s.mockCreateOrUpdateEnvironment(true, nil)
+
+	_, err := s.manager.CreateOrUpdate(s.environmentID, s.request)
+	s.NoError(err)
+	s.runnerManagerMock.AssertCalled(s.T(), "CreateOrUpdateEnvironment",
+		s.environmentID, s.request.PrewarmingPoolSize, templateJob, true)
+}
+
+func (s *CreateOrUpdateTestSuite) TestReturnsErrorIfCreatesOrUpdateEnvironmentReturnsError() {
+	s.mockRegisterTemplateJob(&nomadApi.Job{}, nil)
+	s.mockCreateOrUpdateEnvironment(false, tests.ErrDefault)
+	_, err := s.manager.CreateOrUpdate(runner.EnvironmentID(tests.DefaultEnvironmentIDAsInteger), s.request)
+	s.ErrorIs(err, tests.ErrDefault)
+}
+
+func (s *CreateOrUpdateTestSuite) TestReturnsTrueIfCreatesOrUpdateEnvironmentReturnsTrue() {
+	s.mockRegisterTemplateJob(&nomadApi.Job{}, nil)
+	s.mockCreateOrUpdateEnvironment(true, nil)
+	created, err := s.manager.CreateOrUpdate(runner.EnvironmentID(tests.DefaultEnvironmentIDAsInteger), s.request)
+	s.Require().NoError(err)
+	s.True(created)
+}
+
+func (s *CreateOrUpdateTestSuite) TestReturnsFalseIfCreatesOrUpdateEnvironmentReturnsFalse() {
+	s.mockRegisterTemplateJob(&nomadApi.Job{}, nil)
+	s.mockCreateOrUpdateEnvironment(false, nil)
+	created, err := s.manager.CreateOrUpdate(runner.EnvironmentID(tests.DefaultEnvironmentIDAsInteger), s.request)
+	s.Require().NoError(err)
+	s.False(created)
+}
+
+func TestParseJob(t *testing.T) {
+	exited := false
+	logger, hook := test.NewNullLogger()
+	logger.ExitFunc = func(i int) {
+		exited = true
+	}
+
+	log = logger.WithField("pkg", "nomad")
+
+	t.Run("parses the given default job", func(t *testing.T) {
+		job := parseJob(templateEnvironmentJobHCL)
+		assert.False(t, exited)
+		assert.NotNil(t, job)
+	})
+
+	t.Run("fatals when given wrong job", func(t *testing.T) {
+		job := parseJob("")
+		assert.True(t, exited)
+		assert.Nil(t, job)
+		assert.Equal(t, logrus.FatalLevel, hook.LastEntry().Level)
+	})
+}