Merge pull request #29803 from hashicorp/alisdair/init-backend-provider-errors

cli: Fix backend init failure with deleted cache

internal/command/e2etest/providers_tamper_test.go

@@ -78,6 +78,42 @@ func TestProviderTampering(t *testing.T) {
 			t.Fatalf("unexpected plan error: %s\nstderr:\n%s", err, stderr)
 		}
 	})
+	t.Run("cache dir totally gone, explicit backend", func(t *testing.T) {
+		tf := e2e.NewBinary(terraformBin, seedDir)
+		defer tf.Close()
+		workDir := tf.WorkDir()
+
+		err := ioutil.WriteFile(filepath.Join(workDir, "backend.tf"), []byte(localBackendConfig), 0600)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		err = os.RemoveAll(filepath.Join(workDir, ".terraform"))
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		stdout, stderr, err := tf.Run("plan")
+		if err == nil {
+			t.Fatalf("unexpected plan success\nstdout:\n%s", stdout)
+		}
+		if want := `Initial configuration of the requested backend "local"`; !strings.Contains(stderr, want) {
+			t.Errorf("missing expected error message\nwant substring: %s\ngot:\n%s", want, stderr)
+		}
+		if want := `terraform init`; !strings.Contains(stderr, want) {
+			t.Errorf("missing expected error message\nwant substring: %s\ngot:\n%s", want, stderr)
+		}
+
+		// Running init as suggested resolves the problem
+		_, stderr, err = tf.Run("init")
+		if err != nil {
+			t.Fatalf("unexpected init error: %s\nstderr:\n%s", err, stderr)
+		}
+		_, stderr, err = tf.Run("plan")
+		if err != nil {
+			t.Fatalf("unexpected plan error: %s\nstderr:\n%s", err, stderr)
+		}
+	})
 	t.Run("null plugin package modified before plan", func(t *testing.T) {
 		tf := e2e.NewBinary(terraformBin, seedDir)
 		defer tf.Close()
@@ -229,3 +265,11 @@ func TestProviderTampering(t *testing.T) {
 		}
 	})
 }
+
+const localBackendConfig = `
+terraform {
+  backend "local" {
+    path = "terraform.tfstate"
+  }
+}
+`

internal/command/meta_backend.go

@@ -745,7 +745,7 @@ func (m *Meta) backend_c_r_S(c *configs.Backend, cHash int, sMgr *clistate.Local
 	m.Ui.Output(fmt.Sprintf(strings.TrimSpace(outputBackendMigrateLocal), s.Backend.Type))
 
 	// Grab a purely local backend to get the local state if it exists
-	localB, diags := m.Backend(&BackendOpts{ForceLocal: true})
+	localB, diags := m.Backend(&BackendOpts{ForceLocal: true, Init: true})
 	if diags.HasErrors() {
 		return nil, diags
 	}
@@ -799,7 +799,7 @@ func (m *Meta) backend_C_r_s(c *configs.Backend, cHash int, sMgr *clistate.Local
 	}
 
 	// Grab a purely local backend to get the local state if it exists
-	localB, localBDiags := m.Backend(&BackendOpts{ForceLocal: true})
+	localB, localBDiags := m.Backend(&BackendOpts{ForceLocal: true, Init: true})
 	if localBDiags.HasErrors() {
 		diags = diags.Append(localBDiags)
 		return nil, diags