refactor: Gate pluggable state storage experiment behind the experiment pluggable_state_stores. This is defined via configuration, instead of the old CLI flag -enable-pluggable-state-storage-experiment

This commit removes the old `-enable-pluggable-state-storage-experiment` flag and the equivalent `TF_ENABLE_PLUGGABLE_STATE_STORAGE` ENV. All tests are updated to no longer provide that flag or ENV, and instead all the test fixture configurations are updated to include `experiments = [pluggable_state_stores]`

Author: SarahFrench

internal/command/arguments/init.go

@@ -75,11 +75,6 @@ type Init struct {
 
 	Args []string
 
-	// The -enable-pluggable-state-storage-experiment flag is used in control flow logic in the init command.
-	// TODO(SarahFrench/radeksimko): Remove this once the feature is no longer
-	// experimental
-	EnablePssExperiment bool
-
 	// CreateDefaultWorkspace indicates whether the default workspace should be created by
 	// Terraform when initializing a state store for the first time.
 	CreateDefaultWorkspace bool
@@ -118,9 +113,6 @@ func ParseInit(args []string, experimentsEnabled bool) (*Init, tfdiags.Diagnosti
 	cmdFlags.Var(&init.PluginPath, "plugin-dir", "plugin directory")
 	cmdFlags.BoolVar(&init.CreateDefaultWorkspace, "create-default-workspace", true, "when -input=false, use this flag to block creation of the default workspace")
 
-	// Used for enabling experimental code that's invoked before configuration is parsed.
-	cmdFlags.BoolVar(&init.EnablePssExperiment, "enable-pluggable-state-storage-experiment", false, "Enable the pluggable state storage experiment")
-
 	if err := cmdFlags.Parse(args); err != nil {
 		diags = diags.Append(tfdiags.Sourceless(
 			tfdiags.Error,
@@ -129,44 +121,20 @@ func ParseInit(args []string, experimentsEnabled bool) (*Init, tfdiags.Diagnosti
 		))
 	}
 
-	if v := os.Getenv("TF_ENABLE_PLUGGABLE_STATE_STORAGE"); v != "" {
-		init.EnablePssExperiment = true
-	}
-
 	if v := os.Getenv("TF_SKIP_CREATE_DEFAULT_WORKSPACE"); v != "" {
 		// If TF_SKIP_CREATE_DEFAULT_WORKSPACE is set it will override
 		// a -create-default-workspace=true flag that's set explicitly,
 		// as that's indistinguishable from the default value being used.
 		init.CreateDefaultWorkspace = false
 	}
 
-	if !experimentsEnabled {
-		// If experiments aren't enabled then these flags should not be used.
-		if init.EnablePssExperiment {
-			diags = diags.Append(tfdiags.Sourceless(
-				tfdiags.Error,
-				"Cannot use -enable-pluggable-state-storage-experiment flag without experiments enabled",
-				"Terraform cannot use the -enable-pluggable-state-storage-experiment flag (or TF_ENABLE_PLUGGABLE_STATE_STORAGE environment variable) unless experiments are enabled.",
-			))
-		}
-		if !init.CreateDefaultWorkspace {
-			// Can only be set to false by using the flag
-			// and we cannot identify if -create-default-workspace=true is set explicitly.
-			diags = diags.Append(tfdiags.Sourceless(
-				tfdiags.Error,
-				"Cannot use -create-default-workspace flag without experiments enabled",
-				"Terraform cannot use the -create-default-workspace flag (or TF_SKIP_CREATE_DEFAULT_WORKSPACE environment variable) unless experiments are enabled.",
-			))
-		}
-	} else {
-		// Errors using flags despite experiments being enabled.
-		if !init.CreateDefaultWorkspace && !init.EnablePssExperiment {
-			diags = diags.Append(tfdiags.Sourceless(
-				tfdiags.Error,
-				"Cannot use -create-default-workspace=false flag unless the pluggable state storage experiment is enabled",
-				"Terraform cannot use the -create-default-workspace=false flag (or TF_SKIP_CREATE_DEFAULT_WORKSPACE environment variable) unless you also supply the -enable-pluggable-state-storage-experiment flag (or set the TF_ENABLE_PLUGGABLE_STATE_STORAGE environment variable).",
-			))
-		}
+	if !experimentsEnabled && !init.CreateDefaultWorkspace {
+		// CreateDefaultWorkspace can only be set to false by using the flag
+		diags = diags.Append(tfdiags.Sourceless(
+			tfdiags.Error,
+			"Cannot use -create-default-workspace flag without experiments enabled",
+			"Terraform cannot use the -create-default-workspace flag (or TF_SKIP_CREATE_DEFAULT_WORKSPACE environment variable) unless experiments are enabled.",
+		))
 	}
 
 	if init.MigrateState && init.Json {

internal/command/arguments/init_test.go

@@ -182,18 +182,6 @@ func TestParseInit_experimentalFlags(t *testing.T) {
 		wantErr            string
 		experimentsEnabled bool
 	}{
-		"error: -enable-pluggable-state-storage-experiment and experiments are disabled": {
-			args:               []string{"-enable-pluggable-state-storage-experiment"},
-			experimentsEnabled: false,
-			wantErr:            "Cannot use -enable-pluggable-state-storage-experiment flag without experiments enabled",
-		},
-		"error: TF_ENABLE_PLUGGABLE_STATE_STORAGE is set and experiments are disabled": {
-			envs: map[string]string{
-				"TF_ENABLE_PLUGGABLE_STATE_STORAGE": "1",
-			},
-			experimentsEnabled: false,
-			wantErr:            "Cannot use -enable-pluggable-state-storage-experiment flag without experiments enabled",
-		},
 		"error: -create-default-workspace=false and experiments are disabled": {
 			args:               []string{"-create-default-workspace=false"},
 			experimentsEnabled: false,
@@ -206,18 +194,6 @@ func TestParseInit_experimentalFlags(t *testing.T) {
 			experimentsEnabled: false,
 			wantErr:            "Cannot use -create-default-workspace flag without experiments enabled",
 		},
-		"error: -create-default-workspace=false used without -enable-pluggable-state-storage-experiment, while experiments are enabled": {
-			args:               []string{"-create-default-workspace=false"},
-			experimentsEnabled: true,
-			wantErr:            "Cannot use -create-default-workspace=false flag unless the pluggable state storage experiment is enabled",
-		},
-		"error: TF_SKIP_CREATE_DEFAULT_WORKSPACE used without -enable-pluggable-state-storage-experiment, while experiments are enabled": {
-			envs: map[string]string{
-				"TF_SKIP_CREATE_DEFAULT_WORKSPACE": "1",
-			},
-			experimentsEnabled: true,
-			wantErr:            "Cannot use -create-default-workspace=false flag unless the pluggable state storage experiment is enabled",
-		},
 	}
 
 	for name, tc := range testCases {

internal/command/init.go

@@ -26,6 +26,7 @@ import (
 	"github.com/hashicorp/terraform/internal/configs"
 	"github.com/hashicorp/terraform/internal/configs/configschema"
 	"github.com/hashicorp/terraform/internal/depsfile"
+	"github.com/hashicorp/terraform/internal/experiments"
 	"github.com/hashicorp/terraform/internal/getproviders"
 	"github.com/hashicorp/terraform/internal/getproviders/providerreqs"
 	"github.com/hashicorp/terraform/internal/providercache"
@@ -55,12 +56,22 @@ func (c *InitCommand) Run(args []string) int {
 		return 1
 	}
 
+	path, err := ModulePath(initArgs.Args)
+	if err != nil {
+		diags = diags.Append(err)
+		view.Diagnostics(diags)
+		return 1
+	}
+	rootMod, _ := c.loadSingleModuleWithTests(path, initArgs.TestsDirectory)
+	// We purposefully ignore any diagnostics returned here. They will be encountered downstream,
+	// when the 'run' logic below is executed. If we return early due to error diagnostics here we
+	// will break the order that errors are expected to be raised in.
+
 	// The else condition below invokes the original logic of the init command.
 	// An experimental version of the init code will be used if:
-	// 	> The user uses an experimental version of TF (alpha or built from source)
-	//  > Either the flag -enable-pluggable-state-storage-experiment is passed to the init command.
-	//  > Or, the environment variable TF_ENABLE_PLUGGABLE_STATE_STORAGE is set to any value.
-	if c.Meta.AllowExperimentalFeatures && initArgs.EnablePssExperiment {
+	// 	> The user uses an experimental version of TF (alpha or built from source).
+	//  > The terraform block in the configuration lists the `pluggable_state_stores` experiment.
+	if c.Meta.AllowExperimentalFeatures && rootMod.ActiveExperiments.Has(experiments.PluggableStateStores) {
 		// TODO(SarahFrench/radeksimko): Remove forked init logic once feature is no longer experimental
 		return c.runPssInit(initArgs, view)
 	} else {
@@ -1476,10 +1487,6 @@ Options:
 
   -test-directory=path    Set the Terraform test directory, defaults to "tests".
 
-  -enable-pluggable-state-storage-experiment [EXPERIMENTAL]
-                          A flag to enable an alternative init command that allows use of
-                          pluggable state storage. Only usable with experiments enabled.
-
   -create-default-workspace [EXPERIMENTAL]
                           This flag must be used alongside the -enable-pluggable-state-storage-
                           experiment flag with experiments enabled. This flag's value defaults

internal/command/init_run.go

@@ -14,6 +14,7 @@ import (
 	"github.com/hashicorp/terraform/internal/command/arguments"
 	"github.com/hashicorp/terraform/internal/command/views"
 	"github.com/hashicorp/terraform/internal/configs"
+	"github.com/hashicorp/terraform/internal/experiments"
 	"github.com/hashicorp/terraform/internal/states"
 	"github.com/hashicorp/terraform/internal/terraform"
 	"github.com/hashicorp/terraform/internal/tfdiags"
@@ -142,7 +143,7 @@ func (c *InitCommand) run(initArgs *arguments.Init, view views.Init) int {
 
 		return 1
 	}
-	if !(c.Meta.AllowExperimentalFeatures && initArgs.EnablePssExperiment) && rootModEarly.StateStore != nil {
+	if !(c.Meta.AllowExperimentalFeatures && rootModEarly.ActiveExperiments.Has(experiments.PluggableStateStores)) && rootModEarly.StateStore != nil {
 		// TODO(SarahFrench/radeksimko) - remove when this feature isn't experimental.
 		// This approach for making the feature experimental is required
 		// to let us assert the feature is gated behind an experiment in tests.
@@ -152,11 +153,13 @@ func (c *InitCommand) run(initArgs *arguments.Init, view views.Init) int {
 		if !c.Meta.AllowExperimentalFeatures {
 			detail += " an experimental build of terraform"
 		}
-		if !initArgs.EnablePssExperiment {
+		if !rootModEarly.ActiveExperiments.Has(experiments.PluggableStateStores) {
 			if !c.Meta.AllowExperimentalFeatures {
 				detail += " and"
 			}
-			detail += " -enable-pluggable-state-storage-experiment flag"
+			detail += fmt.Sprintf(" the configuration to opt into the %q experiment using the `terraform` block's `experiments` attribute",
+				experiments.PluggableStateStores.Keyword(),
+			)
 		}
 
 		diags = diags.Append(earlyConfDiags)

internal/command/init_test.go

@@ -223,8 +223,7 @@ func TestInit_two_step_provider_download(t *testing.T) {
 				},
 			}
 
-			args := append(tc.flags, "-enable-pluggable-state-storage-experiment") // Needed to test init changes for PSS project
-			if code := c.Run(args); code != 0 {
+			if code := c.Run(tc.flags); code != 0 {
 				t.Fatalf("bad: \n%s", done(t).All())
 			}
 
@@ -3264,7 +3263,7 @@ func TestInit_stateStore_newWorkingDir(t *testing.T) {
 			Meta: meta,
 		}
 
-		args := []string{"-enable-pluggable-state-storage-experiment=true"}
+		args := []string{}
 		code := c.Run(args)
 		testOutput := done(t)
 		if code != 0 {
@@ -3348,7 +3347,7 @@ func TestInit_stateStore_newWorkingDir(t *testing.T) {
 			},
 		}
 
-		args := []string{"-enable-pluggable-state-storage-experiment=true", "-create-default-workspace=false"}
+		args := []string{"-create-default-workspace=false"}
 		code := c.Run(args)
 		testOutput := done(t)
 		if code != 0 {
@@ -3398,7 +3397,7 @@ func TestInit_stateStore_newWorkingDir(t *testing.T) {
 		}
 
 		t.Setenv("TF_SKIP_CREATE_DEFAULT_WORKSPACE", "1") // any value
-		args := []string{"-enable-pluggable-state-storage-experiment=true"}
+		args := []string{}
 		code := c.Run(args)
 		testOutput := done(t)
 		if code != 0 {
@@ -3453,7 +3452,7 @@ func TestInit_stateStore_newWorkingDir(t *testing.T) {
 			Meta: meta,
 		}
 
-		args := []string{"-enable-pluggable-state-storage-experiment=true"}
+		args := []string{}
 		code := c.Run(args)
 		testOutput := done(t)
 		if code != 1 {
@@ -3527,7 +3526,6 @@ func TestInit_stateStore_newWorkingDir(t *testing.T) {
 
 		// If input is disabled users receive an error about the missing workspace
 		args := []string{
-			"-enable-pluggable-state-storage-experiment=true",
 			"-input=false",
 		}
 		code := c.Run(args)
@@ -3628,9 +3626,7 @@ func TestInit_stateStore_configUnchanged(t *testing.T) {
 		}
 
 		// Run init command
-		args := []string{
-			"-enable-pluggable-state-storage-experiment=true",
-		}
+		args := []string{}
 		code := c.Run(args)
 		testOutput := done(t)
 		if code != 0 {
@@ -3700,7 +3696,6 @@ func TestInit_stateStore_configChanges(t *testing.T) {
 		}
 
 		args := []string{
-			"-enable-pluggable-state-storage-experiment=true",
 			"-reconfigure",
 		}
 		code := c.Run(args)
@@ -3783,9 +3778,7 @@ func TestInit_stateStore_configChanges(t *testing.T) {
 			Meta: meta,
 		}
 
-		args := []string{
-			"-enable-pluggable-state-storage-experiment=true",
-		}
+		args := []string{}
 		code := c.Run(args)
 		testOutput := done(t)
 		if code != 1 {
@@ -3833,9 +3826,7 @@ func TestInit_stateStore_configChanges(t *testing.T) {
 			Meta: meta,
 		}
 
-		args := []string{
-			"-enable-pluggable-state-storage-experiment=true",
-		}
+		args := []string{}
 		code := c.Run(args)
 		testOutput := done(t)
 		if code != 1 {
@@ -3885,9 +3876,7 @@ func TestInit_stateStore_configChanges(t *testing.T) {
 			Meta: meta,
 		}
 
-		args := []string{
-			"-enable-pluggable-state-storage-experiment=true",
-		}
+		args := []string{}
 		code := c.Run(args)
 		testOutput := done(t)
 		if code != 1 {
@@ -3943,9 +3932,7 @@ func TestInit_stateStore_configChanges(t *testing.T) {
 			Meta: meta,
 		}
 
-		args := []string{
-			"-enable-pluggable-state-storage-experiment=true",
-		}
+		args := []string{}
 		code := c.Run(args)
 		testOutput := done(t)
 		if code != 1 {
@@ -3999,7 +3986,6 @@ func TestInit_stateStore_providerUpgrade(t *testing.T) {
 		}
 
 		args := []string{
-			"-enable-pluggable-state-storage-experiment=true",
 			"-upgrade",
 		}
 		code := c.Run(args)
@@ -4054,9 +4040,7 @@ func TestInit_stateStore_unset(t *testing.T) {
 		}
 
 		// Init
-		args := []string{
-			"-enable-pluggable-state-storage-experiment=true",
-		}
+		args := []string{}
 		code := c.Run(args)
 		testOutput := done(t)
 		if code != 0 {
@@ -4096,7 +4080,6 @@ func TestInit_stateStore_unset(t *testing.T) {
 		}
 
 		args := []string{
-			"-enable-pluggable-state-storage-experiment=true",
 			"-force-copy",
 		}
 		code := c.Run(args)
@@ -4152,9 +4135,7 @@ func TestInit_stateStore_unset_withoutProviderRequirements(t *testing.T) {
 		}
 
 		// Init
-		args := []string{
-			"-enable-pluggable-state-storage-experiment=true",
-		}
+		args := []string{}
 		code := c.Run(args)
 		testOutput := done(t)
 		if code != 0 {
@@ -4195,7 +4176,6 @@ func TestInit_stateStore_unset_withoutProviderRequirements(t *testing.T) {
 		}
 
 		args := []string{
-			"-enable-pluggable-state-storage-experiment=true",
 			"-force-copy",
 		}
 		code := c.Run(args)

internal/command/testdata/backend-to-state-store/main.tf

@@ -1,4 +1,5 @@
 terraform {
+  experiments = [pluggable_state_stores]
   required_providers {
     test = {
       source = "hashicorp/test"

internal/command/testdata/init-provider-download/config-and-state-different-providers/main.tf

@@ -1,4 +1,5 @@
 terraform {
+  experiments = [pluggable_state_stores]
   required_providers {
     null = {
       source  = "hashicorp/null"

internal/command/testdata/init-provider-download/config-and-state-same-providers/main.tf

@@ -1,4 +1,5 @@
 terraform {
+  experiments = [pluggable_state_stores]
   required_providers {
     random = {
       source  = "hashicorp/random"

internal/command/testdata/init-provider-download/config-state-file-and-lockfile/main.tf

@@ -1,4 +1,5 @@
 terraform {
+  experiments = [pluggable_state_stores]
   required_providers {
     random = {
       source  = "hashicorp/random"

internal/command/testdata/init-provider-download/state-file-only/main.tf

@@ -1,4 +1,5 @@
 terraform {
+  experiments = [pluggable_state_stores]
   backend "local" {
     path = "./state-using-random-provider.tfstate"
   }