mvu: optionally skip drift check in autoupgrade (#53992)

Previously we ignored drift in autougprade and performed an upgrade
anyway. This PR adds another env var SRC_AUTOUPGRADE_IGNORE_DRIFT that
defaults to false, which acts like how enabling auto-upgrade via the UI
works (disallowed until drift is resolved)

## Test plan


![image](https://github.com/sourcegraph/sourcegraph/assets/18282288/b33fc37d-60de-4264-83bc-b822b2a6e034)

cmd/frontend/graphqlbackend/BUILD.bazel

@@ -234,7 +234,6 @@ go_library(
         "//cmd/frontend/internal/processrestart",
         "//cmd/frontend/internal/search/logs",
         "//cmd/frontend/internal/siteid",
-        "//cmd/migrator/shared",
         "//enterprise/cmd/worker/shared/sourcegraphoperator",
         "//internal/actor",
         "//internal/adminanalytics",

cmd/frontend/graphqlbackend/site.go

@@ -18,7 +18,6 @@ import (
 	"github.com/sourcegraph/sourcegraph/cmd/frontend/graphqlbackend/graphqlutil"
 	"github.com/sourcegraph/sourcegraph/cmd/frontend/internal/app/updatecheck"
 	"github.com/sourcegraph/sourcegraph/cmd/frontend/internal/siteid"
-	migratorshared "github.com/sourcegraph/sourcegraph/cmd/migrator/shared"
 	"github.com/sourcegraph/sourcegraph/internal/actor"
 	"github.com/sourcegraph/sourcegraph/internal/api"
 	"github.com/sourcegraph/sourcegraph/internal/auth"
@@ -338,7 +337,7 @@ var devSchemaFactory = schemas.NewExpectedSchemaFactory(
 )
 
 var schemaFactories = append(
-	migratorshared.DefaultSchemaFactories,
+	schemas.DefaultSchemaFactories,
 	// Special schema factory for dev environment.
 	devSchemaFactory,
 )

cmd/frontend/internal/cli/BUILD.bazel

@@ -49,7 +49,6 @@ go_library(
         "//internal/database/dbconn",
         "//internal/database/dbutil",
         "//internal/database/migration",
-        "//internal/database/migration/cliutil",
         "//internal/database/migration/multiversion",
         "//internal/database/migration/runner",
         "//internal/database/migration/schemas",

cmd/frontend/internal/cli/autoupgrade.go

@@ -15,7 +15,6 @@ import (
 	"github.com/sourcegraph/sourcegraph/internal/database/basestore"
 	connections "github.com/sourcegraph/sourcegraph/internal/database/connections/live"
 	"github.com/sourcegraph/sourcegraph/internal/database/migration"
-	"github.com/sourcegraph/sourcegraph/internal/database/migration/cliutil"
 	"github.com/sourcegraph/sourcegraph/internal/database/migration/multiversion"
 	"github.com/sourcegraph/sourcegraph/internal/database/migration/runner"
 	"github.com/sourcegraph/sourcegraph/internal/database/migration/schemas"
@@ -56,7 +55,7 @@ func tryAutoUpgrade(ctx context.Context, obsvCtx *observation.Context, ready ser
 	} else if err != nil {
 		return errors.Wrap(err, "autoupgradestore.GetAutoUpgrade")
 	}
-	if !dbShouldAutoUpgrade && !cliutil.EnvShouldAutoUpgrade {
+	if !dbShouldAutoUpgrade && !multiversion.EnvShouldAutoUpgrade {
 		return nil
 	}
 
@@ -195,12 +194,12 @@ func runMigration(
 		runner.ApplyPrivilegedMigrations,
 		nil, // only needed when ^ is NoopPrivilegedMigrations
 		true,
-		true,
+		multiversion.EnvAutoUpgradeSkipDrift,
 		false,
 		true,
 		false,
 		registerMigrators,
-		nil, // only needed for drift
+		schemas.DefaultSchemaFactories,
 		out,
 	)
 }

cmd/migrator/shared/main.go

@@ -23,14 +23,6 @@ const appName = "migrator"
 
 var out = output.NewOutput(os.Stdout, output.OutputOpts{})
 
-// DefaultSchemaFactories is a list of schema factories to be used in
-// non-exceptional cases.
-var DefaultSchemaFactories = []schemas.ExpectedSchemaFactory{
-	schemas.LocalExpectedSchemaFactory,
-	schemas.GitHubExpectedSchemaFactory,
-	schemas.GCSExpectedSchemaFactory,
-}
-
 func Start(logger log.Logger, registerEnterpriseMigrators store.RegisterMigratorsUsingConfAndStoreFactoryFunc) error {
 	observationCtx := observation.NewContext(logger)
 
@@ -58,10 +50,10 @@ func Start(logger log.Logger, registerEnterpriseMigrators store.RegisterMigrator
 			cliutil.DownTo(appName, newRunner, outputFactory, false),
 			cliutil.Validate(appName, newRunner, outputFactory),
 			cliutil.Describe(appName, newRunner, outputFactory),
-			cliutil.Drift(appName, newRunner, outputFactory, false, DefaultSchemaFactories...),
+			cliutil.Drift(appName, newRunner, outputFactory, false, schemas.DefaultSchemaFactories...),
 			cliutil.AddLog(appName, newRunner, outputFactory),
-			cliutil.Upgrade(appName, newRunnerWithSchemas, outputFactory, registerMigrators, DefaultSchemaFactories...),
-			cliutil.Downgrade(appName, newRunnerWithSchemas, outputFactory, registerMigrators, DefaultSchemaFactories...),
+			cliutil.Upgrade(appName, newRunnerWithSchemas, outputFactory, registerMigrators, schemas.DefaultSchemaFactories...),
+			cliutil.Downgrade(appName, newRunnerWithSchemas, outputFactory, registerMigrators, schemas.DefaultSchemaFactories...),
 			cliutil.RunOutOfBandMigrations(appName, newRunner, outputFactory, registerMigrators),
 		},
 	}

internal/database/migration/cliutil/BUILD.bazel

@@ -31,7 +31,6 @@ go_library(
         "//internal/database/migration/runner",
         "//internal/database/migration/schemas",
         "//internal/database/migration/store",
-        "//internal/env",
         "//internal/observation",
         "//internal/oobmigration",
         "//internal/oobmigration/migrations",

internal/database/migration/cliutil/up.go

@@ -8,9 +8,9 @@ import (
 	"github.com/jackc/pgerrcode"
 	"github.com/urfave/cli/v2"
 
+	"github.com/sourcegraph/sourcegraph/internal/database/migration/multiversion"
 	"github.com/sourcegraph/sourcegraph/internal/database/migration/runner"
 	"github.com/sourcegraph/sourcegraph/internal/database/migration/store"
-	"github.com/sourcegraph/sourcegraph/internal/env"
 	"github.com/sourcegraph/sourcegraph/internal/oobmigration"
 	"github.com/sourcegraph/sourcegraph/internal/version"
 	"github.com/sourcegraph/sourcegraph/internal/version/upgradestore"
@@ -18,8 +18,6 @@ import (
 	"github.com/sourcegraph/sourcegraph/lib/output"
 )
 
-var EnvShouldAutoUpgrade = env.MustGetBool("SRC_AUTOUPGRADE", false, "If you forgot to set intent to autoupgrade before shutting down the instance, set this env var.")
-
 func Up(commandName string, factory RunnerFactory, outFactory OutputFactory, development bool) *cli.Command {
 	schemaNamesFlag := &cli.StringSliceFlag{
 		Name:    "schema",
@@ -124,7 +122,7 @@ func Up(commandName string, factory RunnerFactory, outFactory OutputFactory, dev
 			return err
 		}
 
-		if EnvShouldAutoUpgrade || dbShouldAutoUpgrade {
+		if multiversion.EnvShouldAutoUpgrade || dbShouldAutoUpgrade {
 			out.WriteLine(output.Emoji(output.EmojiInfo, "Auto-upgrade flag is set, delegating upgrade to frontend instance"))
 			return nil
 		}

internal/database/migration/multiversion/BUILD.bazel

@@ -3,6 +3,7 @@ load("@io_bazel_rules_go//go:def.bzl", "go_library")
 go_library(
     name = "multiversion",
     srcs = [
+        "autoupgrade.go",
         "drift.go",
         "plan.go",
         "run.go",
@@ -18,6 +19,7 @@ go_library(
         "//internal/database/migration/schemas",
         "//internal/database/migration/shared",
         "//internal/database/migration/store",
+        "//internal/env",
         "//internal/observation",
         "//internal/oobmigration",
         "//internal/oobmigration/migrations",

internal/database/migration/multiversion/autoupgrade.go

@@ -0,0 +1,8 @@
+package multiversion
+
+import "github.com/sourcegraph/sourcegraph/internal/env"
+
+var (
+	EnvShouldAutoUpgrade    = env.MustGetBool("SRC_AUTOUPGRADE", false, "If you forgot to set intent to autoupgrade before shutting down the instance, or you're upgrading from pre-5.1, set this env var.")
+	EnvAutoUpgradeSkipDrift = env.MustGetBool("SRC_AUTOUPGRADE_IGNORE_DRIFT", false, "Skip drift checking when performing an autoupgrade.")
+)

internal/database/migration/schemas/drift_schema.go

@@ -13,6 +13,14 @@ import (
 	"github.com/sourcegraph/sourcegraph/lib/errors"
 )
 
+// DefaultSchemaFactories is a list of schema factories to be used in
+// non-exceptional cases.
+var DefaultSchemaFactories = []ExpectedSchemaFactory{
+	LocalExpectedSchemaFactory,
+	GitHubExpectedSchemaFactory,
+	GCSExpectedSchemaFactory,
+}
+
 // ExpectedSchemaFactory converts the given filename and version into a schema description, calling on some
 // external persistent source. When invoked, this function should return a self-describing name, which notably
 // should include _where_ the factory looked for easier debugging on failure, the schema description, and any