Create admin mode on Terraform Workflows (#724)

Modifications within admin mode help for exploring more details around
generated plans. More specifically:
1. Supports clone, init, plan steps as normal
2. Skips validate/apply steps
3. Skips automated cleanup

server/neptune/workflows/activities/terraform/job.go

@@ -53,4 +53,5 @@ type WorkflowMode int
 const (
 	Deploy WorkflowMode = iota
 	PR
+	Admin
 )

server/neptune/workflows/internal/terraform/root_fetcher.go

@@ -27,6 +27,10 @@ func (r *RootFetcher) Fetch(ctx workflow.Context) (*terraform.LocalRoot, func(wo
 		return nil, func(_ workflow.Context) error { return nil }, err
 	}
 
+	if r.Request.WorkflowMode == terraform.Admin {
+		return fetchRootResponse.LocalRoot, func(c workflow.Context) error { return nil }, nil
+	}
+
 	return fetchRootResponse.LocalRoot, func(c workflow.Context) error {
 		var cleanupResponse activities.CleanupResponse
 		err = workflow.ExecuteActivity(c, r.Ta.Cleanup, activities.CleanupRequest{ //nolint:gosimple // unnecessary to add a method to convert reponses

server/neptune/workflows/internal/terraform/workflow.go

@@ -350,6 +350,10 @@ func (r *Runner) run(ctx workflow.Context) (Response, error) {
 		return Response{}, r.toExternalError(err, "running plan job")
 	}
 
+	if r.Request.WorkflowMode == terraform.Admin {
+		return Response{}, nil
+	}
+
 	if r.Request.WorkflowMode == terraform.PR {
 		validationResults, err := r.Validate(ctx, root, response.ServerURL, planResponse.PlanJSONFile)
 		if err != nil {

server/neptune/workflows/internal/terraform/workflow_test.go

@@ -176,6 +176,10 @@ func testTerraformWorkflow(ctx workflow.Context, req request) (*response, error)
 		WorkflowMode: req.WorkflowMode,
 	}
 
+	if req.WorkflowMode == terraformModel.Admin {
+		tAct = nil
+	}
+
 	subject := &terraform.Runner{
 		ReviewGate: &gate.Review{
 			Timeout:        30 * time.Second,
@@ -615,6 +619,88 @@ func TestSuccess_PRMode(t *testing.T) {
 	}, resp.States)
 }
 
+func TestSuccess_AdminMode(t *testing.T) {
+	var suite testsuite.WorkflowTestSuite
+	env := suite.NewTestWorkflowEnvironment()
+	ga := &githubActivities{}
+	ta := &terraformActivities{}
+	env.RegisterActivity(ga)
+	env.RegisterActivity(ta)
+
+	outputURL, err := url.Parse("www.test.com/jobs/1235")
+	assert.NoError(t, err)
+
+	// set activity expectations
+	env.OnActivity(ga.GithubFetchRoot, mock.MatchedBy(func(ctx context.Context) bool {
+		info := activity.GetInfo(ctx)
+
+		assert.Equal(t, "taskqueue", info.TaskQueue)
+		assert.Equal(t, 1*time.Minute, info.HeartbeatTimeout)
+
+		return true
+	}), activities.FetchRootRequest{
+		Repo:         testGithubRepo,
+		Root:         testLocalRoot.Root,
+		DeploymentID: testDeploymentID,
+	}).Return(activities.FetchRootResponse{
+		LocalRoot:       testLocalRoot,
+		DeployDirectory: DeployDir,
+	}, nil)
+
+	// execute workflow
+	env.ExecuteWorkflow(testTerraformWorkflow, request{
+		WorkflowMode: terraformModel.Admin,
+	})
+	assert.True(t, env.IsWorkflowCompleted())
+
+	var resp response
+	err = env.GetWorkflowResult(&resp)
+	assert.NoError(t, err)
+
+	// assert results are expected
+	env.AssertExpectations(t)
+	assert.Equal(t, []state.Workflow{
+		{
+			Plan: &state.Job{
+				Status: state.WaitingJobStatus,
+				Output: &state.JobOutput{
+					URL: outputURL,
+				},
+			},
+		},
+		{
+			Plan: &state.Job{
+				Status: state.InProgressJobStatus,
+				Output: &state.JobOutput{
+					URL: outputURL,
+				},
+			},
+		},
+		{
+			Plan: &state.Job{
+				Status: state.SuccessJobStatus,
+				Output: &state.JobOutput{
+					URL:         outputURL,
+					PlanSummary: planSummary,
+				},
+			},
+		},
+		{
+			Plan: &state.Job{
+				Status: state.SuccessJobStatus,
+				Output: &state.JobOutput{
+					URL:         outputURL,
+					PlanSummary: planSummary,
+				},
+			},
+			Result: state.WorkflowResult{
+				Reason: state.SuccessfulCompletionReason,
+				Status: state.CompleteWorkflowStatus,
+			},
+		},
+	}, resp.States)
+}
+
 func TestSuccess_PRMode_FailedPolicy(t *testing.T) {
 	var suite testsuite.WorkflowTestSuite
 	env := suite.NewTestWorkflowEnvironment()