backend: Faster remote backend tests

The remote backend tests spent most of their execution time sleeping in
various polling and backoff waits. This is unnecessary when testing
against a mock server, so reduce all of these delays when under test to
much lower values.

Only one remaining test has an artificial delay: verifying the discovery
of services against an unknown hostname. This times out at DNS
resolution, which is more difficult to fix than seems worth it at this
time.

backend/remote/backend_apply_test.go

@@ -542,8 +542,8 @@ func TestRemote_applyApprovedExternally(t *testing.T) {
 		t.Fatalf("error starting operation: %v", err)
 	}
 
-	// Wait 2 seconds to make sure the run started.
+	// Wait 50 milliseconds to make sure the run started.
-	time.Sleep(2 * time.Second)
+	time.Sleep(50 * time.Millisecond)
 
 	wl, err := b.client.Workspaces.List(
 		ctx,
@@ -617,8 +617,8 @@ func TestRemote_applyDiscardedExternally(t *testing.T) {
 		t.Fatalf("error starting operation: %v", err)
 	}
 
-	// Wait 2 seconds to make sure the run started.
+	// Wait 50 milliseconds to make sure the run started.
-	time.Sleep(2 * time.Second)
+	time.Sleep(50 * time.Millisecond)
 
 	wl, err := b.client.Workspaces.List(
 		ctx,
@@ -871,7 +871,7 @@ func TestRemote_applyLockTimeout(t *testing.T) {
 		"approve": "yes",
 	})
 
-	op.StateLockTimeout = 5 * time.Second
+	op.StateLockTimeout = 50 * time.Millisecond
 	op.UIIn = input
 	op.UIOut = b.CLI
 	op.Workspace = backend.DefaultStateName
@@ -887,8 +887,8 @@ func TestRemote_applyLockTimeout(t *testing.T) {
 	case <-sigint:
 		// Stop redirecting SIGINT signals.
 		signal.Stop(sigint)
-	case <-time.After(10 * time.Second):
+	case <-time.After(200 * time.Millisecond):
-		t.Fatalf("expected lock timeout after 5 seconds, waited 10 seconds")
+		t.Fatalf("expected lock timeout after 50 milliseconds, waited 200 milliseconds")
 	}
 
 	if len(input.answers) != 2 {

backend/remote/backend_common.go

@@ -24,6 +24,13 @@ var (
 	errRunOverridden    = errors.New("overridden using the UI or API")
 )
 
+var (
+	backoffMin = 1000.0
+	backoffMax = 3000.0
+
+	runPollInterval = 3 * time.Second
+)
+
 // backoff will perform exponential backoff based on the iteration and
 // limited by the provided min and max (in milliseconds) durations.
 func backoff(min, max float64, iter int) time.Duration {
@@ -43,7 +50,7 @@ func (b *Remote) waitForRun(stopCtx, cancelCtx context.Context, op *backend.Oper
 			return r, stopCtx.Err()
 		case <-cancelCtx.Done():
 			return r, cancelCtx.Err()
-		case <-time.After(backoff(1000, 3000, i)):
+		case <-time.After(backoff(backoffMin, backoffMax, i)):
 			// Timer up, show status
 		}
 
@@ -260,7 +267,7 @@ func (b *Remote) costEstimate(stopCtx, cancelCtx context.Context, op *backend.Op
 			return stopCtx.Err()
 		case <-cancelCtx.Done():
 			return cancelCtx.Err()
-		case <-time.After(1 * time.Second):
+		case <-time.After(backoff(backoffMin, backoffMax, i)):
 		}
 
 		// Retrieve the cost estimate to get its current status.
@@ -454,7 +461,7 @@ func (b *Remote) confirm(stopCtx context.Context, op *backend.Operation, opts *t
 				return
 			case <-stopCtx.Done():
 				return
-			case <-time.After(3 * time.Second):
+			case <-time.After(runPollInterval):
 				// Retrieve the run again to get its current status.
 				r, err := b.client.Runs.Read(stopCtx, r.ID)
 				if err != nil {

backend/remote/backend_mock.go

@@ -360,7 +360,7 @@ func (m *mockLogReader) Read(l []byte) (int, error) {
 		if written, err := m.read(l); err != io.ErrNoProgress {
 			return written, err
 		}
-		time.Sleep(500 * time.Millisecond)
+		time.Sleep(1 * time.Millisecond)
 	}
 }
 

backend/remote/backend_plan.go

@@ -20,6 +20,8 @@ import (
 	"github.com/hashicorp/terraform/tfdiags"
 )
 
+var planConfigurationVersionsPollInterval = 500 * time.Millisecond
+
 func (b *Remote) opPlan(stopCtx, cancelCtx context.Context, op *backend.Operation, w *tfe.Workspace) (*tfe.Run, error) {
 	log.Printf("[INFO] backend/remote: starting Plan operation")
 
@@ -213,7 +215,7 @@ in order to capture the filesystem context the remote workspace expects:
 			return nil, context.Canceled
 		case <-cancelCtx.Done():
 			return nil, context.Canceled
-		case <-time.After(500 * time.Millisecond):
+		case <-time.After(planConfigurationVersionsPollInterval):
 			cv, err = b.client.ConfigurationVersions.Read(stopCtx, cv.ID)
 			if err != nil {
 				return nil, generalError("Failed to retrieve configuration version", err)

backend/remote/backend_plan_test.go

@@ -620,7 +620,7 @@ func TestRemote_planLockTimeout(t *testing.T) {
 		"approve": "yes",
 	})
 
-	op.StateLockTimeout = 5 * time.Second
+	op.StateLockTimeout = 50 * time.Millisecond
 	op.UIIn = input
 	op.UIOut = b.CLI
 	op.Workspace = backend.DefaultStateName
@@ -636,8 +636,8 @@ func TestRemote_planLockTimeout(t *testing.T) {
 	case <-sigint:
 		// Stop redirecting SIGINT signals.
 		signal.Stop(sigint)
-	case <-time.After(10 * time.Second):
+	case <-time.After(200 * time.Millisecond):
-		t.Fatalf("expected lock timeout after 5 seconds, waited 10 seconds")
+		t.Fatalf("expected lock timeout after 50 milliseconds, waited 200 milliseconds")
 	}
 
 	if len(input.answers) != 2 {

backend/remote/remote_test.go

@@ -4,6 +4,7 @@ import (
 	"flag"
 	"os"
 	"testing"
+	"time"
 
 	_ "github.com/hashicorp/terraform/internal/logging"
 )
@@ -14,5 +15,11 @@ func TestMain(m *testing.M) {
 	// Make sure TF_FORCE_LOCAL_BACKEND is unset
 	os.Unsetenv("TF_FORCE_LOCAL_BACKEND")
 
+	// Reduce delays to make tests run faster
+	backoffMin = 1.0
+	backoffMax = 1.0
+	planConfigurationVersionsPollInterval = 1 * time.Millisecond
+	runPollInterval = 1 * time.Millisecond
+
 	os.Exit(m.Run())
 }