server: add TestBumpClusterVersion

Tests the machinery that's being used to bump cluster versions during version
upgrades. Pulled out of our prototype in cockroachdb#57445.

Release note: None

pkg/server/migration_test.go

@@ -16,6 +16,7 @@ import (
 
 	"github.com/cockroachdb/cockroach/pkg/base"
 	"github.com/cockroachdb/cockroach/pkg/clusterversion"
+	"github.com/cockroachdb/cockroach/pkg/kv/kvserver"
 	"github.com/cockroachdb/cockroach/pkg/roachpb"
 	"github.com/cockroachdb/cockroach/pkg/server/serverpb"
 	"github.com/cockroachdb/cockroach/pkg/settings/cluster"
@@ -96,3 +97,97 @@ func TestValidateTargetClusterVersion(t *testing.T) {
 		s.Stopper().Stop(context.Background())
 	}
 }
+
+func TestBumpClusterVersion(t *testing.T) {
+	defer leaktest.AfterTest(t)()
+
+	v := func(major, minor int32) roachpb.Version {
+		return roachpb.Version{Major: major, Minor: minor}
+	}
+	cv := func(major, minor int32) clusterversion.ClusterVersion {
+		return clusterversion.ClusterVersion{Version: v(major, minor)}
+	}
+
+	var tests = []struct {
+		binaryVersion        roachpb.Version
+		activeClusterVersion clusterversion.ClusterVersion // akin to min supported binary version
+		bumpClusterVersion   clusterversion.ClusterVersion
+		expClusterVersion    clusterversion.ClusterVersion
+	}{
+		{
+			binaryVersion:        v(21, 1),
+			activeClusterVersion: cv(20, 2),
+			bumpClusterVersion:   cv(20, 2),
+			expClusterVersion:    cv(20, 2),
+		},
+		{
+			binaryVersion:        v(21, 1),
+			activeClusterVersion: cv(20, 2),
+			bumpClusterVersion:   cv(21, 1),
+			expClusterVersion:    cv(21, 1),
+		},
+		{
+			binaryVersion:        v(21, 1),
+			activeClusterVersion: cv(21, 1),
+			bumpClusterVersion:   cv(20, 2),
+			expClusterVersion:    cv(21, 1),
+		},
+	}
+
+	ctx := context.Background()
+	for _, test := range tests {
+		st := cluster.MakeTestingClusterSettingsWithVersions(
+			test.binaryVersion,
+			test.activeClusterVersion.Version,
+			false, /* initializeVersion */
+		)
+
+		s, _, _ := serverutils.StartServer(t, base.TestServerArgs{
+			Settings: st,
+			Knobs: base.TestingKnobs{
+				Server: &TestingKnobs{
+					// This test wants to bootstrap at the previously active
+					// cluster version, so we can actually bump the cluster
+					// version to the binary version. Think a cluster with
+					// active cluster version v20.1, but running v20.2 binaries.
+					BinaryVersionOverride: test.activeClusterVersion.Version,
+					// We're bumping cluster versions manually ourselves. We
+					// want avoid racing with the auto-upgrade process.
+					DisableAutomaticVersionUpgrade: 1,
+				},
+			},
+		})
+
+		// Check to see our pre-bump active cluster version is what we expect.
+		if got := s.ClusterSettings().Version.ActiveVersion(ctx); got != test.activeClusterVersion {
+			t.Fatalf("expected active cluster version %s, got %s", test.activeClusterVersion, got)
+		}
+
+		migrationServer := s.MigrationServer().(*migrationServer)
+		req := &serverpb.BumpClusterVersionRequest{
+			ClusterVersion: &test.bumpClusterVersion,
+		}
+		if _, err := migrationServer.BumpClusterVersion(ctx, req); err != nil {
+			t.Fatal(err)
+		}
+
+		// Check to see our post-bump active cluster version is what we expect.
+		if got := s.ClusterSettings().Version.ActiveVersion(ctx); got != test.expClusterVersion {
+			t.Fatalf("expected active cluster version %s, got %s", test.expClusterVersion, got)
+		}
+
+		// Check to see that our bumped cluster version was persisted to disk.
+		synthesizedCV, err := kvserver.SynthesizeClusterVersionFromEngines(
+			ctx, s.Engines(), test.binaryVersion,
+			test.activeClusterVersion.Version,
+		)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if synthesizedCV != test.expClusterVersion {
+			t.Fatalf("expected synthesized cluster version %s, got %s", test.expClusterVersion, synthesizedCV)
+		}
+
+		s.Stopper().Stop(context.Background())
+	}
+}

pkg/testutils/serverutils/BUILD.bazel

@@ -15,6 +15,7 @@ go_library(
         "//pkg/rpc",
         "//pkg/security",
         "//pkg/settings/cluster",
+        "//pkg/storage",
         "//pkg/testutils/sqlutils",
         "//pkg/util/hlc",
         "//pkg/util/httputil",

pkg/testutils/serverutils/test_server_shim.go

@@ -30,6 +30,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/rpc"
 	"github.com/cockroachdb/cockroach/pkg/security"
 	"github.com/cockroachdb/cockroach/pkg/settings/cluster"
+	"github.com/cockroachdb/cockroach/pkg/storage"
 	"github.com/cockroachdb/cockroach/pkg/testutils/sqlutils"
 	"github.com/cockroachdb/cockroach/pkg/util/hlc"
 	"github.com/cockroachdb/cockroach/pkg/util/httputil"
@@ -220,6 +221,9 @@ type TestServerInterface interface {
 	// Calling this multiple times is undefined (but see
 	// TestCluster.ScratchRange() which is idempotent).
 	ScratchRange() (roachpb.Key, error)
+
+	// Engines returns the TestServer's engines.
+	Engines() []storage.Engine
 }
 
 // TestServerFactory encompasses the actual implementation of the shim