Add option to configure template job HCL file

Previously, the template job HCL file was hardcoded using go:embed
in the binary. However, this did not allow users running Poseidon
to change its content. Now, users can change the content of the
template job HCL file using the configuration option.

internal/environment/manager_test.go

@@ -2,15 +2,15 @@ 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/require"
 	"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"
+	"os"
 	"testing"
 )
 
@@ -119,24 +119,66 @@ func (s *CreateOrUpdateTestSuite) TestReturnsFalseIfCreatesOrUpdateEnvironmentRe
 }
 
 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)
+		job, err := parseJob(templateEnvironmentJobHCL)
+		assert.NoError(t, err)
 		assert.NotNil(t, job)
 	})
 
-	t.Run("fatals when given wrong job", func(t *testing.T) {
-		job := parseJob("")
-		assert.True(t, exited)
+	t.Run("returns error when given wrong job", func(t *testing.T) {
+		job, err := parseJob("")
+		assert.Error(t, err)
 		assert.Nil(t, job)
-		assert.Equal(t, logrus.FatalLevel, hook.LastEntry().Level)
 	})
 }
+
+func TestNewNomadEnvironmentManager(t *testing.T) {
+	executorAPIMock := &nomad.ExecutorAPIMock{}
+	executorAPIMock.On("LoadEnvironmentJobs").Return([]*nomadApi.Job{}, nil)
+
+	runnerManagerMock := &runner.ManagerMock{}
+	runnerManagerMock.On("Load").Return()
+
+	previousTemplateEnvironmentJobHCL := templateEnvironmentJobHCL
+
+	t.Run("returns error if template file does not exist", func(t *testing.T) {
+		_, err := NewNomadEnvironmentManager(runnerManagerMock, executorAPIMock, "/non-existent/file")
+		assert.Error(t, err)
+	})
+
+	t.Run("loads template environment job from file", func(t *testing.T) {
+		templateJobHCL := "job \"test\" {}"
+		expectedJob, err := parseJob(templateJobHCL)
+		require.NoError(t, err)
+		f := createTempFile(t, templateJobHCL)
+		defer os.Remove(f.Name())
+
+		m, err := NewNomadEnvironmentManager(runnerManagerMock, executorAPIMock, f.Name())
+		assert.NoError(t, err)
+		assert.NotNil(t, m)
+		assert.Equal(t, templateJobHCL, templateEnvironmentJobHCL)
+		assert.Equal(t, *expectedJob, m.templateEnvironmentJob)
+	})
+
+	t.Run("returns error if template file is invalid", func(t *testing.T) {
+		templateJobHCL := "invalid hcl file"
+		f := createTempFile(t, templateJobHCL)
+		defer os.Remove(f.Name())
+
+		_, err := NewNomadEnvironmentManager(runnerManagerMock, executorAPIMock, f.Name())
+		assert.Error(t, err)
+	})
+
+	templateEnvironmentJobHCL = previousTemplateEnvironmentJobHCL
+}
+
+func createTempFile(t *testing.T, content string) *os.File {
+	t.Helper()
+	f, err := os.CreateTemp("", "test")
+	require.NoError(t, err)
+	n, err := f.WriteString(content)
+	require.NoError(t, err)
+	require.Equal(t, len(content), n)
+
+	return f
+}