From 3cc58813f088fac3b9d008372052694ae1f75914 Mon Sep 17 00:00:00 2001
From: Sander van Harmelen <sander@xanzy.io>
Date: Sat, 8 Sep 2018 11:12:03 +0200
Subject: [PATCH] backend/remote: use a search query and use pagination

To prevent making unnecessary heavy calls to the backend, we should use a search query to limit the result.

But even if we use a search query, we should still use the pagination details to make sure we retrieved all items.
---
 backend/remote/backend.go                     | 52 +++++++++++++------
 backend/remote/backend_mock.go                | 29 +++++++++--
 .../test-fixtures/plan-scaleout/main.tf       | 10 ----
 3 files changed, 62 insertions(+), 29 deletions(-)
 delete mode 100644 backend/remote/test-fixtures/plan-scaleout/main.tf

diff --git a/backend/remote/backend.go b/backend/remote/backend.go
index 5c00edd2f..e36ca8ef0 100644
--- a/backend/remote/backend.go
+++ b/backend/remote/backend.go
@@ -251,9 +251,10 @@ func (b *Remote) State(workspace string) (state.State, error) {
 	}
 
 	// Configure the remote workspace name.
-	if workspace == backend.DefaultStateName {
+	switch {
+	case workspace == backend.DefaultStateName:
 		workspace = b.workspace
-	} else if b.prefix != "" && !strings.HasPrefix(workspace, b.prefix) {
+	case b.prefix != "" && !strings.HasPrefix(workspace, b.prefix):
 		workspace = b.prefix + workspace
 	}
 
@@ -293,9 +294,10 @@ func (b *Remote) DeleteState(workspace string) error {
 	}
 
 	// Configure the remote workspace name.
-	if workspace == backend.DefaultStateName {
+	switch {
+	case workspace == backend.DefaultStateName:
 		workspace = b.workspace
-	} else if b.prefix != "" && !strings.HasPrefix(workspace, b.prefix) {
+	case b.prefix != "" && !strings.HasPrefix(workspace, b.prefix):
 		workspace = b.prefix + workspace
 	}
 
@@ -336,20 +338,39 @@ func (b *Remote) states() ([]string, error) {
 	}
 
 	options := tfe.WorkspaceListOptions{}
-	wl, err := b.client.Workspaces.List(context.Background(), b.organization, options)
-	if err != nil {
-		return nil, err
+	switch {
+	case b.workspace != "":
+		options.Search = tfe.String(b.workspace)
+	case b.prefix != "":
+		options.Search = tfe.String(b.prefix)
 	}
 
+	// Create a slice to contain all the names.
 	var names []string
-	for _, w := range wl.Items {
-		if b.workspace != "" && w.Name == b.workspace {
-			names = append(names, backend.DefaultStateName)
-			continue
+
+	for {
+		wl, err := b.client.Workspaces.List(context.Background(), b.organization, options)
+		if err != nil {
+			return nil, err
 		}
-		if b.prefix != "" && strings.HasPrefix(w.Name, b.prefix) {
-			names = append(names, strings.TrimPrefix(w.Name, b.prefix))
+
+		for _, w := range wl.Items {
+			if b.workspace != "" && w.Name == b.workspace {
+				names = append(names, backend.DefaultStateName)
+				continue
+			}
+			if b.prefix != "" && strings.HasPrefix(w.Name, b.prefix) {
+				names = append(names, strings.TrimPrefix(w.Name, b.prefix))
+			}
 		}
+
+		// Exit the loop when we've seen all pages.
+		if wl.CurrentPage == wl.TotalPages {
+			break
+		}
+
+		// Update the page number to get the next page.
+		options.PageNumber = wl.NextPage
 	}
 
 	// Sort the result so we have consistent output.
@@ -361,9 +382,10 @@ func (b *Remote) states() ([]string, error) {
 // Operation implements backend.Enhanced
 func (b *Remote) Operation(ctx context.Context, op *backend.Operation) (*backend.RunningOperation, error) {
 	// Configure the remote workspace name.
-	if op.Workspace == backend.DefaultStateName {
+	switch {
+	case op.Workspace == backend.DefaultStateName:
 		op.Workspace = b.workspace
-	} else if b.prefix != "" && !strings.HasPrefix(op.Workspace, b.prefix) {
+	case b.prefix != "" && !strings.HasPrefix(op.Workspace, b.prefix):
 		op.Workspace = b.prefix + op.Workspace
 	}
 
diff --git a/backend/remote/backend_mock.go b/backend/remote/backend_mock.go
index 673b5c81c..c680eb770 100644
--- a/backend/remote/backend_mock.go
+++ b/backend/remote/backend_mock.go
@@ -413,17 +413,38 @@ func newMockWorkspaces(client *mockClient) *mockWorkspaces {
 }
 
 func (m *mockWorkspaces) List(ctx context.Context, organization string, options tfe.WorkspaceListOptions) (*tfe.WorkspaceList, error) {
+	dummyWorkspaces := 10
 	wl := &tfe.WorkspaceList{}
+
+	// We return dummy workspaces for the first page to test pagination.
+	if options.PageNumber <= 1 {
+		for i := 0; i < dummyWorkspaces; i++ {
+			wl.Items = append(wl.Items, &tfe.Workspace{
+				ID:   generateID("ws-"),
+				Name: fmt.Sprintf("dummy-workspace-%d", i),
+			})
+		}
+
+		wl.Pagination = &tfe.Pagination{
+			CurrentPage: 1,
+			NextPage:    2,
+			TotalPages:  2,
+			TotalCount:  len(wl.Items) + len(m.workspaceIDs),
+		}
+
+		return wl, nil
+	}
+
+	// The second page will return any actual results.
 	for _, w := range m.workspaceIDs {
 		wl.Items = append(wl.Items, w)
 	}
 
 	wl.Pagination = &tfe.Pagination{
-		CurrentPage:  1,
-		NextPage:     1,
+		CurrentPage:  2,
 		PreviousPage: 1,
-		TotalPages:   1,
-		TotalCount:   len(wl.Items),
+		TotalPages:   2,
+		TotalCount:   len(wl.Items) + dummyWorkspaces,
 	}
 
 	return wl, nil
diff --git a/backend/remote/test-fixtures/plan-scaleout/main.tf b/backend/remote/test-fixtures/plan-scaleout/main.tf
deleted file mode 100644
index 4067af592..000000000
--- a/backend/remote/test-fixtures/plan-scaleout/main.tf
+++ /dev/null
@@ -1,10 +0,0 @@
-resource "test_instance" "foo" {
-  count = 3
-  ami   = "bar"
-
-  # This is here because at some point it caused a test failure
-  network_interface {
-    device_index = 0
-    description  = "Main network interface"
-  }
-}