Remove pinned builtin plugin versions from storage (#18051)

* Removes _builtin_ versions from mount storage where it already exists
* Stops new builtin versions being put into storage on mount creation/tuning
* Stops the plugin catalog from returning a builtin plugin that has been overridden, so it more accurately reflects the plugins that are available to actually run

builtin/logical/database/backend_test.go

@@ -13,7 +13,9 @@ import (
 	"time"
 
 	"github.com/go-test/deep"
+	"github.com/hashicorp/go-hclog"
 	mongodbatlas "github.com/hashicorp/vault-plugin-database-mongodbatlas"
+	"github.com/hashicorp/vault/helper/builtinplugins"
 	"github.com/hashicorp/vault/helper/namespace"
 	postgreshelper "github.com/hashicorp/vault/helper/testhelpers/postgresql"
 	vaulthttp "github.com/hashicorp/vault/http"
@@ -36,6 +38,7 @@ func getCluster(t *testing.T) (*vault.TestCluster, logical.SystemView) {
 		LogicalBackends: map[string]logical.Factory{
 			"database": Factory,
 		},
+		BuiltinRegistry: builtinplugins.Registry,
 	}
 
 	cluster := vault.NewTestCluster(t, coreConfig, &vault.TestClusterOptions{
@@ -1550,6 +1553,15 @@ func TestBackend_AsyncClose(t *testing.T) {
 	}
 }
 
+func TestNewDatabaseWrapper_IgnoresBuiltinVersion(t *testing.T) {
+	cluster, sys := getCluster(t)
+	t.Cleanup(cluster.Cleanup)
+	_, err := newDatabaseWrapper(context.Background(), "hana-database-plugin", "v1.0.0+builtin", sys, hclog.Default())
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
 func testCredsExist(t *testing.T, resp *logical.Response, connURL string) bool {
 	t.Helper()
 	var d struct {

builtin/logical/database/path_config_connection.go

@@ -11,6 +11,7 @@ import (
 	"github.com/hashicorp/go-uuid"
 	"github.com/hashicorp/go-version"
 
+	"github.com/hashicorp/vault/helper/versions"
 	v5 "github.com/hashicorp/vault/sdk/database/dbplugin/v5"
 	"github.com/hashicorp/vault/sdk/framework"
 	"github.com/hashicorp/vault/sdk/helper/consts"
@@ -228,6 +229,12 @@ func (b *databaseBackend) connectionReadHandler() framework.OperationFunc {
 			}
 		}
 
+		if versions.IsBuiltinVersion(config.PluginVersion) {
+			// This gets treated as though it's empty when mounting, and will get
+			// overwritten to be empty when the config is next written. See #18051.
+			config.PluginVersion = ""
+		}
+
 		delete(config.ConnectionDetails, "password")
 		delete(config.ConnectionDetails, "private_key")
 
@@ -295,7 +302,10 @@ func (b *databaseBackend) connectionWriteHandler() framework.OperationFunc {
 			config.PluginVersion = pluginVersionRaw.(string)
 		}
 
-		unversionedPlugin, err := b.System().LookupPlugin(ctx, config.PluginName, consts.PluginTypeDatabase)
+		var builtinShadowed bool
+		if unversionedPlugin, err := b.System().LookupPlugin(ctx, config.PluginName, consts.PluginTypeDatabase); err == nil && !unversionedPlugin.Builtin {
+			builtinShadowed = true
+		}
 		switch {
 		case config.PluginVersion != "":
 			semanticVersion, err := version.NewVersion(config.PluginVersion)
@@ -305,7 +315,16 @@ func (b *databaseBackend) connectionWriteHandler() framework.OperationFunc {
 
 			// Canonicalize the version.
 			config.PluginVersion = "v" + semanticVersion.String()
-		case err == nil && !unversionedPlugin.Builtin:
+
+			if config.PluginVersion == versions.GetBuiltinVersion(consts.PluginTypeDatabase, config.PluginName) {
+				if builtinShadowed {
+					return logical.ErrorResponse("database plugin %q, version %s not found, as it is"+
+						" overridden by an unversioned plugin of the same name. Omit `plugin_version` to use the unversioned plugin", config.PluginName, config.PluginVersion), nil
+				}
+
+				config.PluginVersion = ""
+			}
+		case builtinShadowed:
 			// We'll select the unversioned plugin that's been registered.
 		case req.Operation == logical.CreateOperation:
 			// No version provided and no unversioned plugin of that name available.
@@ -407,6 +426,11 @@ func (b *databaseBackend) connectionWriteHandler() framework.OperationFunc {
 			oldConn.Close()
 		}
 
+		// 1.12.0 and 1.12.1 stored builtin plugins in storage, but 1.12.2 reverted
+		// that, so clean up any pre-existing stored builtin versions on write.
+		if versions.IsBuiltinVersion(config.PluginVersion) {
+			config.PluginVersion = ""
+		}
 		err = storeConfig(ctx, req.Storage, name, config)
 		if err != nil {
 			return nil, err

builtin/logical/database/path_config_connection_test.go

@@ -0,0 +1,166 @@
+package database
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"github.com/hashicorp/vault/helper/namespace"
+	"github.com/hashicorp/vault/helper/versions"
+	"github.com/hashicorp/vault/sdk/helper/consts"
+	"github.com/hashicorp/vault/sdk/logical"
+)
+
+func TestWriteConfig_PluginVersionInStorage(t *testing.T) {
+	cluster, sys := getCluster(t)
+	t.Cleanup(cluster.Cleanup)
+
+	config := logical.TestBackendConfig()
+	config.StorageView = &logical.InmemStorage{}
+	config.System = sys
+
+	b, err := Factory(context.Background(), config)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer b.Cleanup(context.Background())
+
+	const hdb = "hana-database-plugin"
+	hdbBuiltin := versions.GetBuiltinVersion(consts.PluginTypeDatabase, hdb)
+
+	// Configure a connection
+	writePluginVersion := func() {
+		t.Helper()
+		req := &logical.Request{
+			Operation: logical.UpdateOperation,
+			Path:      "config/plugin-test",
+			Storage:   config.StorageView,
+			Data: map[string]interface{}{
+				"connection_url":    "test",
+				"plugin_name":       hdb,
+				"plugin_version":    hdbBuiltin,
+				"verify_connection": false,
+			},
+		}
+		resp, err := b.HandleRequest(namespace.RootContext(nil), req)
+		if err != nil || (resp != nil && resp.IsError()) {
+			t.Fatalf("err:%s resp:%#v\n", err, resp)
+		}
+	}
+	writePluginVersion()
+
+	getPluginVersionFromAPI := func() string {
+		t.Helper()
+		req := &logical.Request{
+			Operation: logical.ReadOperation,
+			Path:      "config/plugin-test",
+			Storage:   config.StorageView,
+		}
+
+		resp, err := b.HandleRequest(namespace.RootContext(nil), req)
+		if err != nil || (resp != nil && resp.IsError()) {
+			t.Fatalf("err:%s resp:%#v\n", err, resp)
+		}
+
+		return resp.Data["plugin_version"].(string)
+	}
+	pluginVersion := getPluginVersionFromAPI()
+	if pluginVersion != "" {
+		t.Fatalf("expected plugin_version empty but got %s", pluginVersion)
+	}
+
+	// Directly store config to get the builtin plugin version into storage,
+	// simulating a write that happened before upgrading to 1.12.2+
+	err = storeConfig(context.Background(), config.StorageView, "plugin-test", &DatabaseConfig{
+		PluginName:    hdb,
+		PluginVersion: hdbBuiltin,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Now replay the read request, and we still shouldn't get the builtin version back.
+	pluginVersion = getPluginVersionFromAPI()
+	if pluginVersion != "" {
+		t.Fatalf("expected plugin_version empty but got %s", pluginVersion)
+	}
+
+	// Check the underlying data, which should still have the version in storage.
+	getPluginVersionFromStorage := func() string {
+		t.Helper()
+		entry, err := config.StorageView.Get(context.Background(), "config/plugin-test")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if entry == nil {
+			t.Fatal()
+		}
+
+		var config DatabaseConfig
+		if err := entry.DecodeJSON(&config); err != nil {
+			t.Fatal(err)
+		}
+		return config.PluginVersion
+	}
+
+	storagePluginVersion := getPluginVersionFromStorage()
+	if storagePluginVersion != hdbBuiltin {
+		t.Fatalf("Expected %s, got: %s", hdbBuiltin, storagePluginVersion)
+	}
+
+	// Trigger a write to storage, which should clean up plugin version in the storage entry.
+	writePluginVersion()
+
+	storagePluginVersion = getPluginVersionFromStorage()
+	if storagePluginVersion != "" {
+		t.Fatalf("Expected empty, got: %s", storagePluginVersion)
+	}
+
+	// Finally, confirm API requests still return empty plugin version too
+	pluginVersion = getPluginVersionFromAPI()
+	if pluginVersion != "" {
+		t.Fatalf("expected plugin_version empty but got %s", pluginVersion)
+	}
+}
+
+func TestWriteConfig_HelpfulErrorMessageWhenBuiltinOverridden(t *testing.T) {
+	cluster, sys := getCluster(t)
+	t.Cleanup(cluster.Cleanup)
+
+	config := logical.TestBackendConfig()
+	config.StorageView = &logical.InmemStorage{}
+	config.System = sys
+
+	b, err := Factory(context.Background(), config)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer b.Cleanup(context.Background())
+
+	const pg = "postgresql-database-plugin"
+	pgBuiltin := versions.GetBuiltinVersion(consts.PluginTypeDatabase, pg)
+
+	// Configure a connection
+	data := map[string]interface{}{
+		"connection_url":    "test",
+		"plugin_name":       pg,
+		"plugin_version":    pgBuiltin,
+		"verify_connection": false,
+	}
+	req := &logical.Request{
+		Operation: logical.UpdateOperation,
+		Path:      "config/plugin-test",
+		Storage:   config.StorageView,
+		Data:      data,
+	}
+	resp, err := b.HandleRequest(namespace.RootContext(nil), req)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if resp == nil || !resp.IsError() {
+		t.Fatalf("resp:%#v", resp)
+	}
+	if !strings.Contains(resp.Error().Error(), "overridden by an unversioned plugin") {
+		t.Fatalf("expected overridden error but got: %s", resp.Error())
+	}
+}

builtin/logical/database/path_rotate_credentials.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/hashicorp/vault/helper/versions"
 	v5 "github.com/hashicorp/vault/sdk/database/dbplugin/v5"
 	"github.com/hashicorp/vault/sdk/framework"
 	"github.com/hashicorp/vault/sdk/logical"
@@ -137,6 +138,11 @@ func (b *databaseBackend) pathRotateRootCredentialsUpdate() framework.OperationF
 			config.ConnectionDetails = newConfigDetails
 		}
 
+		// 1.12.0 and 1.12.1 stored builtin plugins in storage, but 1.12.2 reverted
+		// that, so clean up any pre-existing stored builtin versions on write.
+		if versions.IsBuiltinVersion(config.PluginVersion) {
+			config.PluginVersion = ""
+		}
 		err = storeConfig(ctx, req.Storage, name, config)
 		if err != nil {
 			return nil, err

builtin/logical/database/version_wrapper.go

@@ -6,6 +6,7 @@ import (
 
 	log "github.com/hashicorp/go-hclog"
 	"github.com/hashicorp/go-multierror"
+	"github.com/hashicorp/vault/helper/versions"
 	v4 "github.com/hashicorp/vault/sdk/database/dbplugin"
 	v5 "github.com/hashicorp/vault/sdk/database/dbplugin/v5"
 	"github.com/hashicorp/vault/sdk/helper/pluginutil"
@@ -22,8 +23,15 @@ type databaseVersionWrapper struct {
 var _ logical.PluginVersioner = databaseVersionWrapper{}
 
 // newDatabaseWrapper figures out which version of the database the pluginName is referring to and returns a wrapper object
-// that can be used to make operations on the underlying database plugin.
+// that can be used to make operations on the underlying database plugin. If a builtin pluginVersion is provided, it will
+// be ignored.
 func newDatabaseWrapper(ctx context.Context, pluginName string, pluginVersion string, sys pluginutil.LookRunnerUtil, logger log.Logger) (dbw databaseVersionWrapper, err error) {
+	// 1.12.0 and 1.12.1 stored plugin version in the config, but that stored
+	// builtin version may disappear from the plugin catalog when Vault is
+	// upgraded, so always reference builtin plugins by an empty version.
+	if versions.IsBuiltinVersion(pluginVersion) {
+		pluginVersion = ""
+	}
 	newDB, err := v5.PluginFactoryVersion(ctx, pluginName, pluginVersion, sys, logger)
 	if err == nil {
 		dbw = databaseVersionWrapper{

changelog/18051.txt

@@ -0,0 +1,6 @@
+```release-note:change
+plugins: Mounts can no longer be pinned to a specific _builtin_ version. Mounts previously pinned to a specific builtin version will now automatically upgrade to the latest builtin version, and may now be overridden if an unversioned plugin of the same name and type is registered. Mounts using plugin versions without `builtin` in their metadata remain unaffected.
+```
+```release-note:bug
+plugins: Vault upgrades will no longer fail if a mount has been created using an explicit builtin plugin version.
+```

helper/versions/version.go

@@ -6,14 +6,19 @@ import (
 	"strings"
 	"sync"
 
+	semver "github.com/hashicorp/go-version"
 	"github.com/hashicorp/vault/sdk/helper/consts"
 	"github.com/hashicorp/vault/sdk/version"
 )
 
+const (
+	BuiltinMetadata = "builtin"
+)
+
 var (
 	buildInfoOnce         sync.Once // once is used to ensure we only parse build info once.
 	buildInfo             *debug.BuildInfo
-	DefaultBuiltinVersion = "v" + version.GetVersion().Version + "+builtin.vault"
+	DefaultBuiltinVersion = fmt.Sprintf("v%s+%s.vault", version.GetVersion().Version, BuiltinMetadata)
 )
 
 func GetBuiltinVersion(pluginType consts.PluginType, pluginName string) string {
@@ -46,9 +51,28 @@ func GetBuiltinVersion(pluginType consts.PluginType, pluginName string) string {
 
 	for _, dep := range buildInfo.Deps {
 		if dep.Path == pluginModulePath {
-			return dep.Version + "+builtin"
+			return dep.Version + "+" + BuiltinMetadata
 		}
 	}
 
 	return DefaultBuiltinVersion
 }
+
+// IsBuiltinVersion checks for the "builtin" metadata identifier in a plugin's
+// semantic version. Vault rejects any plugin registration requests with this
+// identifier, so we can be certain it's a builtin plugin if it's present.
+func IsBuiltinVersion(v string) bool {
+	semanticVersion, err := semver.NewSemver(v)
+	if err != nil {
+		return false
+	}
+
+	metadataIdentifiers := strings.Split(semanticVersion.Metadata(), ".")
+	for _, identifier := range metadataIdentifiers {
+		if identifier == BuiltinMetadata {
+			return true
+		}
+	}
+
+	return false
+}

helper/versions/version_test.go

@@ -0,0 +1,23 @@
+package versions
+
+import "testing"
+
+func TestIsBuiltinVersion(t *testing.T) {
+	for _, tc := range []struct {
+		version string
+		builtin bool
+	}{
+		{"v1.0.0+builtin", true},
+		{"v2.3.4+builtin.vault", true},
+		{"1.0.0+builtin.anythingelse", true},
+		{"v1.0.0+other.builtin", true},
+		{"v1.0.0+builtinbutnot", false},
+		{"v1.0.0", false},
+		{"not-a-semver", false},
+	} {
+		builtin := IsBuiltinVersion(tc.version)
+		if builtin != tc.builtin {
+			t.Fatalf("%s should give: %v, but got %v", tc.version, tc.builtin, builtin)
+		}
+	}
+}

vault/auth.go

@@ -636,6 +636,12 @@ func (c *Core) loadCredentials(ctx context.Context) error {
 			needPersist = true
 		}
 
+		// Don't store built-in version in the mount table, to make upgrades smoother.
+		if versions.IsBuiltinVersion(entry.Version) {
+			entry.Version = ""
+			needPersist = true
+		}
+
 		if entry.NamespaceID == "" {
 			entry.NamespaceID = namespace.RootNamespaceID
 			needPersist = true

vault/logical_system.go

@@ -635,20 +635,12 @@ func getVersion(d *framework.FieldData) (version string, builtin bool, err error
 			return "", false, fmt.Errorf("version %q is not a valid semantic version: %w", version, err)
 		}
 
-		metadataIdentifiers := strings.Split(semanticVersion.Metadata(), ".")
-		for _, identifier := range metadataIdentifiers {
-			if identifier == "builtin" {
-				builtin = true
-				break
-			}
-		}
-
 		// Canonicalize the version string.
 		// Add the 'v' back in, since semantic version strips it out, and we want to be consistent with internal plugins.
 		version = "v" + semanticVersion.String()
 	}
 
-	return version, builtin, nil
+	return version, versions.IsBuiltinVersion(version), nil
 }
 
 func (b *SystemBackend) handlePluginReloadUpdate(ctx context.Context, req *logical.Request, d *framework.FieldData) (*logical.Response, error) {
@@ -2636,6 +2628,19 @@ func (b *SystemBackend) validateVersion(ctx context.Context, version string, plu
 
 		// Canonicalize the version.
 		version = "v" + semanticVersion.String()
+
+		if version == versions.GetBuiltinVersion(pluginType, pluginName) {
+			unversionedPlugin, err := b.System().LookupPlugin(ctx, pluginName, pluginType)
+			if err == nil && !unversionedPlugin.Builtin {
+				// Builtin is overridden, return "not found" error.
+				return "", logical.ErrorResponse("%s plugin %q, version %s not found, as it is"+
+					" overridden by an unversioned plugin of the same name. Omit `plugin_version` to use the unversioned plugin", pluginType.String(), pluginName, version), nil
+			}
+
+			// Don't put the builtin version in storage. Ensures that builtins
+			// can always be overridden, and upgrades are much simpler to handle.
+			version = ""
+		}
 	}
 
 	// if a non-builtin version is requested for a builtin plugin, return an error

vault/logical_system_test.go

@@ -5113,3 +5113,171 @@ func TestSortVersionedPlugins(t *testing.T) {
 		})
 	}
 }
+
+func TestValidateVersion(t *testing.T) {
+	b := testSystemBackend(t).(*SystemBackend)
+	k8sAuthBuiltin := versions.GetBuiltinVersion(consts.PluginTypeCredential, "kubernetes")
+
+	for name, tc := range map[string]struct {
+		pluginName         string
+		pluginVersion      string
+		pluginType         consts.PluginType
+		expectLogicalError string
+		expectedVersion    string
+	}{
+		"default, nothing in nothing out":   {"kubernetes", "", consts.PluginTypeCredential, "", ""},
+		"builtin specified, empty out":      {"kubernetes", k8sAuthBuiltin, consts.PluginTypeCredential, "", ""},
+		"not canonical is ok":               {"kubernetes", "1.0.0", consts.PluginTypeCredential, "", "v1.0.0"},
+		"not a semantic version, error":     {"kubernetes", "not-a-version", consts.PluginTypeCredential, "not a valid semantic version", ""},
+		"can't select non-builtin token":    {"token", "v1.0.0", consts.PluginTypeCredential, "cannot select non-builtin version", ""},
+		"can't select non-builtin identity": {"identity", "v1.0.0", consts.PluginTypeSecrets, "cannot select non-builtin version", ""},
+	} {
+		t.Run(name, func(t *testing.T) {
+			version, resp, err := b.validateVersion(context.Background(), tc.pluginVersion, tc.pluginName, tc.pluginType)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if tc.expectLogicalError != "" {
+				if resp == nil || !resp.IsError() || resp.Error() == nil {
+					t.Errorf("expected logical error but got none, resp: %#v", resp)
+				}
+				if !strings.Contains(resp.Error().Error(), tc.expectLogicalError) {
+					t.Errorf("expected logical error to contain %q, but got: %s", tc.expectLogicalError, resp.Error())
+				}
+			} else if version != tc.expectedVersion {
+				t.Errorf("expected version %q but got %q", tc.expectedVersion, version)
+			}
+		})
+	}
+}
+
+func TestValidateVersion_HelpfulErrorWhenBuiltinOverridden(t *testing.T) {
+	core, _, _ := TestCoreUnsealed(t)
+	tempDir, err := filepath.EvalSymlinks(t.TempDir())
+	if err != nil {
+		t.Fatal(err)
+	}
+	core.pluginCatalog.directory = tempDir
+	b := core.systemBackend
+
+	// Shadow a builtin and test getting a helpful error back.
+	file, err := ioutil.TempFile(tempDir, "temp")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer file.Close()
+
+	command := filepath.Base(file.Name())
+	err = core.pluginCatalog.Set(context.Background(), "kubernetes", consts.PluginTypeCredential, "", command, nil, nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// When we validate the version now, we should get a special error message
+	// about why the builtin isn't there.
+	k8sAuthBuiltin := versions.GetBuiltinVersion(consts.PluginTypeCredential, "kubernetes")
+	_, resp, err := b.validateVersion(context.Background(), k8sAuthBuiltin, "kubernetes", consts.PluginTypeCredential)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if resp == nil || !resp.IsError() || resp.Error() == nil {
+		t.Errorf("expected logical error but got none, resp: %#v", resp)
+	}
+	if !strings.Contains(resp.Error().Error(), "overridden by an unversioned plugin of the same name") {
+		t.Errorf("expected logical error to contain overridden message, but got: %s", resp.Error())
+	}
+}
+
+func TestCanUnseal_WithNonExistentBuiltinPluginVersion_InMountStorage(t *testing.T) {
+	core, keys, _ := TestCoreUnsealed(t)
+	ctx := namespace.RootContext(nil)
+	testCases := []struct {
+		pluginName string
+		pluginType consts.PluginType
+		mountTable string
+	}{
+		{"consul", consts.PluginTypeSecrets, "mounts"},
+		{"approle", consts.PluginTypeCredential, "auth"},
+	}
+	readMountConfig := func(pluginName, mountTable string) map[string]interface{} {
+		t.Helper()
+		req := logical.TestRequest(t, logical.ReadOperation, mountTable+"/"+pluginName)
+		resp, err := core.systemBackend.HandleRequest(ctx, req)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		return resp.Data
+	}
+
+	for _, tc := range testCases {
+		req := logical.TestRequest(t, logical.UpdateOperation, tc.mountTable+"/"+tc.pluginName)
+		req.Data["type"] = tc.pluginName
+		req.Data["config"] = map[string]interface{}{
+			"default_lease_ttl": "35m",
+			"max_lease_ttl":     "45m",
+			"plugin_version":    versions.GetBuiltinVersion(tc.pluginType, tc.pluginName),
+		}
+
+		resp, err := core.systemBackend.HandleRequest(ctx, req)
+		if err != nil {
+			t.Fatalf("err: %v, resp: %#v", err, resp)
+		}
+		if resp != nil {
+			t.Fatalf("bad: %v", resp)
+		}
+
+		config := readMountConfig(tc.pluginName, tc.mountTable)
+		pluginVersion, ok := config["plugin_version"]
+		if !ok || pluginVersion != "" {
+			t.Fatalf("expected empty plugin version in config: %#v", config)
+		}
+
+		// Directly store plugin version in mount entry, so we can then simulate
+		// an upgrade from 1.12.1 to 1.12.2 by sealing and unsealing.
+		const nonExistentBuiltinVersion = "v1.0.0+builtin"
+		var mountEntry *MountEntry
+		if tc.mountTable == "mounts" {
+			mountEntry, err = core.mounts.find(ctx, tc.pluginName+"/")
+		} else {
+			mountEntry, err = core.auth.find(ctx, tc.pluginName+"/")
+		}
+		if err != nil {
+			t.Fatal(err)
+		}
+		if mountEntry == nil {
+			t.Fatal()
+		}
+		mountEntry.Version = nonExistentBuiltinVersion
+		err = core.persistMounts(ctx, core.mounts, &mountEntry.Local)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		config = readMountConfig(tc.pluginName, tc.mountTable)
+		pluginVersion, ok = config["plugin_version"]
+		if !ok || pluginVersion != nonExistentBuiltinVersion {
+			t.Fatalf("expected plugin version %s but was %s, config: %#v", nonExistentBuiltinVersion, pluginVersion, config)
+		}
+	}
+
+	err := TestCoreSeal(core)
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, key := range keys {
+		if _, err := TestCoreUnseal(core, TestKeyCopy(key)); err != nil {
+			t.Fatalf("unseal err: %s", err)
+		}
+	}
+
+	for _, tc := range testCases {
+		// Storage should have been upgraded during the unseal, so plugin version
+		// should be empty again.
+		config := readMountConfig(tc.pluginName, tc.mountTable)
+		pluginVersion, ok := config["plugin_version"]
+		if !ok || pluginVersion != "" {
+			t.Errorf("expected empty plugin version in config: %#v", config)
+		}
+	}
+}

vault/mount.go

@@ -727,8 +727,7 @@ func (c *Core) builtinTypeFromMountEntry(ctx context.Context, entry *MountEntry)
 		return consts.PluginTypeUnknown
 	}
 
-	// Builtin plugins should contain the "builtin" string in their RunningVersion
+	if !versions.IsBuiltinVersion(entry.RunningVersion) {
-	if !strings.Contains(entry.RunningVersion, "builtin") {
 		return consts.PluginTypeUnknown
 	}
 
@@ -1317,6 +1316,11 @@ func (c *Core) runMountUpdates(ctx context.Context, needPersist bool) error {
 			needPersist = true
 		}
 
+		// Don't store built-in version in the mount table, to make upgrades smoother.
+		if versions.IsBuiltinVersion(entry.Version) {
+			entry.Version = ""
+			needPersist = true
+		}
 	}
 	// Done if we have restored the mount table and we don't need
 	// to persist

vault/mount_test.go

@@ -13,6 +13,7 @@ import (
 	"github.com/hashicorp/vault/audit"
 	"github.com/hashicorp/vault/helper/metricsutil"
 	"github.com/hashicorp/vault/helper/namespace"
+	"github.com/hashicorp/vault/helper/versions"
 	"github.com/hashicorp/vault/sdk/helper/compressutil"
 	"github.com/hashicorp/vault/sdk/helper/jsonutil"
 	"github.com/hashicorp/vault/sdk/logical"
@@ -206,7 +207,7 @@ func TestCore_Mount_secrets_builtin_RunningVersion(t *testing.T) {
 
 	raw, _ := c.router.root.Get(match)
 	// we override the running version of builtins
-	if !strings.Contains(raw.(*routeEntry).mountEntry.RunningVersion, "builtin") {
+	if !versions.IsBuiltinVersion(raw.(*routeEntry).mountEntry.RunningVersion) {
 		t.Errorf("Expected mount to have builtin version but got %s", raw.(*routeEntry).mountEntry.RunningVersion)
 	}
 }

vault/plugin_catalog.go

@@ -833,6 +833,14 @@ func (c *PluginCatalog) get(ctx context.Context, name string, pluginType consts.
 
 	builtinVersion := versions.GetBuiltinVersion(pluginType, name)
 	if version == "" || version == builtinVersion {
+		if version == builtinVersion {
+			// Don't return the builtin if it's shadowed by an unversioned plugin.
+			unversioned, err := c.get(ctx, name, pluginType, "")
+			if err == nil && unversioned != nil && !unversioned.Builtin {
+				return nil, nil
+			}
+		}
+
 		// Look for builtin plugins
 		if factory, ok := c.builtinRegistry.Get(name, pluginType); ok {
 			return &pluginutil.PluginRunner{

vault/plugin_catalog_test.go

@@ -40,11 +40,18 @@ func TestPluginCatalog_CRUD(t *testing.T) {
 		t.Fatalf("unexpected error %v", err)
 	}
 
+	// Get it again, explicitly specifying builtin version
+	builtinVersion := versions.GetBuiltinVersion(consts.PluginTypeDatabase, pluginName)
+	p2, err := core.pluginCatalog.Get(context.Background(), pluginName, consts.PluginTypeDatabase, builtinVersion)
+	if err != nil {
+		t.Fatalf("unexpected error %v", err)
+	}
+
 	expectedBuiltin := &pluginutil.PluginRunner{
 		Name:    pluginName,
 		Type:    consts.PluginTypeDatabase,
 		Builtin: true,
-		Version: versions.GetBuiltinVersion(consts.PluginTypeDatabase, pluginName),
+		Version: builtinVersion,
 	}
 	expectedBuiltin.BuiltinFactory, _ = builtinplugins.Registry.Get(pluginName, consts.PluginTypeDatabase)
 
@@ -53,9 +60,13 @@ func TestPluginCatalog_CRUD(t *testing.T) {
 	}
 	expectedBuiltin.BuiltinFactory = nil
 	p.BuiltinFactory = nil
+	p2.BuiltinFactory = nil
 	if !reflect.DeepEqual(p, expectedBuiltin) {
 		t.Fatalf("expected did not match actual, got %#v\n expected %#v\n", p, expectedBuiltin)
 	}
+	if !reflect.DeepEqual(p2, expectedBuiltin) {
+		t.Fatalf("expected did not match actual, got %#v\n expected %#v\n", p2, expectedBuiltin)
+	}
 
 	// Set a plugin, test overwriting a builtin plugin
 	file, err := ioutil.TempFile(tempDir, "temp")
@@ -76,6 +87,16 @@ func TestPluginCatalog_CRUD(t *testing.T) {
 		t.Fatalf("unexpected error %v", err)
 	}
 
+	// Get it again, explicitly specifying builtin version.
+	// This time it should fail because it was overwritten.
+	p2, err = core.pluginCatalog.Get(context.Background(), pluginName, consts.PluginTypeDatabase, builtinVersion)
+	if err != nil {
+		t.Fatalf("unexpected error %v", err)
+	}
+	if p2 != nil {
+		t.Fatalf("expected no result, got: %#v", p2)
+	}
+
 	expected := &pluginutil.PluginRunner{
 		Name:    pluginName,
 		Type:    consts.PluginTypeDatabase,
@@ -383,7 +404,7 @@ func TestPluginCatalog_ListVersionedPlugins(t *testing.T) {
 			if !plugin.Builtin {
 				t.Fatalf("expected %v plugin to be builtin", plugin)
 			}
-			if plugin.SemanticVersion.Metadata() != "builtin" && plugin.SemanticVersion.Metadata() != "builtin.vault" {
+			if !versions.IsBuiltinVersion(plugin.Version) {
 				t.Fatalf("expected +builtin metadata but got %s", plugin.Version)
 			}
 		}

vault/testing.go

@@ -2247,6 +2247,7 @@ func NewMockBuiltinRegistry() *mockBuiltinRegistry {
 			"postgresql-database-plugin": consts.PluginTypeDatabase,
 			"approle":                    consts.PluginTypeCredential,
 			"aws":                        consts.PluginTypeCredential,
+			"consul":                     consts.PluginTypeSecrets,
 		},
 	}
 }
@@ -2255,7 +2256,6 @@ type mockBuiltinRegistry struct {
 	forTesting map[string]consts.PluginType
 }
 
-// Get only supports getting database plugins, and approle
 func (m *mockBuiltinRegistry) Get(name string, pluginType consts.PluginType) (func() (interface{}, error), bool) {
 	testPluginType, ok := m.forTesting[name]
 	if !ok {
@@ -2265,28 +2265,35 @@ func (m *mockBuiltinRegistry) Get(name string, pluginType consts.PluginType) (fu
 		return nil, false
 	}
 
-	if name == "approle" {
+	switch name {
+	case "approle":
 		return toFunc(approle.Factory), true
-	}
+	case "aws":
-
-	if name == "aws" {
 		return toFunc(func(ctx context.Context, config *logical.BackendConfig) (logical.Backend, error) {
 			b := new(framework.Backend)
 			b.Setup(ctx, config)
 			b.BackendType = logical.TypeCredential
 			return b, nil
 		}), true
-	}
+	case "postgresql-database-plugin":
-
-	if name == "postgresql-database-plugin" {
 		return toFunc(func(ctx context.Context, config *logical.BackendConfig) (logical.Backend, error) {
 			b := new(framework.Backend)
 			b.Setup(ctx, config)
 			b.BackendType = logical.TypeLogical
 			return b, nil
 		}), true
-	}
+	case "mysql-database-plugin":
 		return dbMysql.New(dbMysql.DefaultUserNameTemplate), true
+	case "consul":
+		return toFunc(func(ctx context.Context, config *logical.BackendConfig) (logical.Backend, error) {
+			b := new(framework.Backend)
+			b.Setup(ctx, config)
+			b.BackendType = logical.TypeLogical
+			return b, nil
+		}), true
+	default:
+		return nil, false
+	}
 }
 
 // Keys only supports getting a realistic list of the keys for database plugins,