Merge pull request #29792 from hashicorp/alisdair/init-missing-cache

cli: Fix init failure with deleted cache

internal/command/e2etest/providers_tamper_test.go

@@ -57,7 +57,7 @@ func TestProviderTampering(t *testing.T) {
 			t.Fatal(err)
 		}
 
-		_, stderr, err := tf.Run("plan")
+		stdout, stderr, err := tf.Run("plan")
 		if err == nil {
 			t.Fatalf("unexpected plan success\nstdout:\n%s", stdout)
 		}
@@ -67,6 +67,16 @@ func TestProviderTampering(t *testing.T) {
 		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)

internal/command/init.go

@@ -238,7 +238,7 @@ func (c *InitCommand) Run(args []string) int {
 		// by a previous run, so we must still expect that "back" may be nil
 		// in code that follows.
 		var backDiags tfdiags.Diagnostics
-		back, backDiags = c.Backend(nil)
+		back, backDiags = c.Backend(&BackendOpts{Init: true})
 		if backDiags.HasErrors() {
 			// This is fine. We'll proceed with no backend, then.
 			back = nil

internal/command/meta.go

@@ -459,10 +459,8 @@ func (m *Meta) contextOpts() (*terraform.ContextOpts, error) {
 		opts.Providers = m.testingOverrides.Providers
 		opts.Provisioners = m.testingOverrides.Provisioners
 	} else {
-		providerFactories, err := m.providerFactories()
-		if err != nil {
-			return nil, err
-		}
+		var providerFactories map[addrs.Provider]providers.Factory
+		providerFactories, err = m.providerFactories()
 		opts.Providers = providerFactories
 		opts.Provisioners = m.provisionerFactories()
 	}
@@ -472,7 +470,7 @@ func (m *Meta) contextOpts() (*terraform.ContextOpts, error) {
 		OriginalWorkingDir: m.WorkingDir.OriginalWorkingDir(),
 	}
 
-	return &opts, nil
+	return &opts, err
 }
 
 // defaultFlagSet creates a default flag set for commands.

internal/command/meta_backend.go

@@ -112,28 +112,34 @@ func (m *Meta) Backend(opts *BackendOpts) (backend.Enhanced, tfdiags.Diagnostics
 			// indicates one or more inconsistencies between the dependency
 			// lock file and the provider plugins actually available in the
 			// local cache directory.
-			var buf bytes.Buffer
-			for addr, err := range errs {
-				fmt.Fprintf(&buf, "\n  - %s: %s", addr, err)
+			//
+			// If initialization is allowed, we ignore this error, as it may
+			// be resolved by the later step where providers are fetched.
+			if !opts.Init {
+				var buf bytes.Buffer
+				for addr, err := range errs {
+					fmt.Fprintf(&buf, "\n  - %s: %s", addr, err)
+				}
+				suggestion := "To download the plugins required for this configuration, run:\n  terraform init"
+				if m.RunningInAutomation {
+					// Don't mention "terraform init" specifically if we're running in an automation wrapper
+					suggestion = "You must install the required plugins before running Terraform operations."
+				}
+				diags = diags.Append(tfdiags.Sourceless(
+					tfdiags.Error,
+					"Required plugins are not installed",
+					fmt.Sprintf(
+						"The installed provider plugins are not consistent with the packages selected in the dependency lock file:%s\n\nTerraform uses external plugins to integrate with a variety of different infrastructure services. %s",
+						buf.String(), suggestion,
+					),
+				))
+				return nil, diags
 			}
-			suggestion := "To download the plugins required for this configuration, run:\n  terraform init"
-			if m.RunningInAutomation {
-				// Don't mention "terraform init" specifically if we're running in an automation wrapper
-				suggestion = "You must install the required plugins before running Terraform operations."
-			}
-			diags = diags.Append(tfdiags.Sourceless(
-				tfdiags.Error,
-				"Required plugins are not installed",
-				fmt.Sprintf(
-					"The installed provider plugins are not consistent with the packages selected in the dependency lock file:%s\n\nTerraform uses external plugins to integrate with a variety of different infrastructure services. %s",
-					buf.String(), suggestion,
-				),
-			))
 		} else {
 			// All other errors just get generic handling.
 			diags = diags.Append(err)
+			return nil, diags
 		}
-		return nil, diags
 	}
 	cliOpts.Validation = true
 
@@ -337,7 +343,7 @@ func (m *Meta) BackendForPlan(settings plans.Backend) (backend.Enhanced, tfdiags
 // a backend that supports local CLI operations.
 func (m *Meta) backendCLIOpts() (*backend.CLIOpts, error) {
 	contextOpts, err := m.contextOpts()
-	if err != nil {
+	if contextOpts == nil && err != nil {
 		return nil, err
 	}
 	return &backend.CLIOpts{
@@ -350,7 +356,7 @@ func (m *Meta) backendCLIOpts() (*backend.CLIOpts, error) {
 		ContextOpts:         contextOpts,
 		Input:               m.Input(),
 		RunningInAutomation: m.RunningInAutomation,
-	}, nil
+	}, err
 }
 
 // Operation initializes a new backend.Operation struct.