Merge branch 'main' of ssh://github.com/hashicorp/consul

.changelog/14149.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+agent: Fixed a compatibility issue when restoring snapshots from pre-1.13.0 versions of Consul [[GH-14107](https://github.com/hashicorp/consul/issues/14107)]
+```

agent/consul/fsm/snapshot_oss.go

@@ -1,8 +1,12 @@
 package fsm
 
 import (
+	"fmt"
+	"net"
+
 	"github.com/hashicorp/consul-net-rpc/go-msgpack/codec"
 	"github.com/hashicorp/raft"
+	"github.com/mitchellh/mapstructure"
 
 	"github.com/hashicorp/consul/agent/consul/state"
 	"github.com/hashicorp/consul/agent/structs"
@@ -886,11 +890,43 @@ func restoreSystemMetadata(header *SnapshotHeader, restore *state.Restore, decod
 }
 
 func restoreServiceVirtualIP(header *SnapshotHeader, restore *state.Restore, decoder *codec.Decoder) error {
-	var req state.ServiceVirtualIP
+	// state.ServiceVirtualIP was changed in a breaking way in 1.13.0 (2e4cb6f77d2be36b02e9be0b289b24e5b0afb794).
+	// We attempt to reconcile the older type by decoding to a map then decoding that map into
+	// structs.PeeredServiceName first, and then structs.ServiceName.
+	var req struct {
+		Service map[string]interface{}
+		IP      net.IP
+
+		structs.RaftIndex
+	}
 	if err := decoder.Decode(&req); err != nil {
 		return err
 	}
-	if err := restore.ServiceVirtualIP(req); err != nil {
+
+	vip := state.ServiceVirtualIP{
+		IP:        req.IP,
+		RaftIndex: req.RaftIndex,
+	}
+
+	// PeeredServiceName is the expected primary key type.
+	var psn structs.PeeredServiceName
+	if err := mapstructure.Decode(req.Service, &psn); err != nil {
+		return fmt.Errorf("cannot decode to structs.PeeredServiceName: %w", err)
+	}
+	vip.Service = psn
+
+	// If the expected primary key field is empty, it must be the older ServiceName type.
+	if vip.Service.ServiceName.Name == "" {
+		var sn structs.ServiceName
+		if err := mapstructure.Decode(req.Service, &sn); err != nil {
+			return fmt.Errorf("cannot decode to structs.ServiceName: %w", err)
+		}
+		vip.Service = structs.PeeredServiceName{
+			ServiceName: sn,
+		}
+	}
+
+	if err := restore.ServiceVirtualIP(vip); err != nil {
 		return err
 	}
 	return nil

agent/consul/fsm/snapshot_oss_test.go

@@ -3,6 +3,7 @@ package fsm
 import (
 	"bytes"
 	"fmt"
+	"net"
 	"testing"
 	"time"
 
@@ -962,3 +963,66 @@ func TestFSM_BadSnapshot_NilCAConfig(t *testing.T) {
 	require.EqualValues(t, 0, idx)
 	require.Nil(t, config)
 }
+
+// This test asserts that ServiceVirtualIP, which made a breaking change
+// in 1.13.0, can still restore from older snapshots which use the old
+// state.ServiceVirtualIP type.
+func Test_restoreServiceVirtualIP(t *testing.T) {
+	psn := structs.PeeredServiceName{
+		ServiceName: structs.ServiceName{
+			Name: "foo",
+		},
+	}
+
+	run := func(t *testing.T, input interface{}) {
+		t.Helper()
+
+		var b []byte
+		buf := bytes.NewBuffer(b)
+		// Encode input
+		encoder := codec.NewEncoder(buf, structs.MsgpackHandle)
+		require.NoError(t, encoder.Encode(input))
+
+		// Create a decoder
+		dec := codec.NewDecoder(buf, structs.MsgpackHandle)
+
+		logger := testutil.Logger(t)
+		fsm, err := New(nil, logger)
+		require.NoError(t, err)
+
+		restore := fsm.State().Restore()
+
+		// Call restore
+		require.NoError(t, restoreServiceVirtualIP(nil, restore, dec))
+		require.NoError(t, restore.Commit())
+
+		ip, err := fsm.State().VirtualIPForService(psn)
+		require.NoError(t, err)
+
+		// 240->224 due to addIPOffset
+		require.Equal(t, "224.0.0.2", ip)
+	}
+
+	t.Run("new ServiceVirtualIP with PeeredServiceName", func(t *testing.T) {
+		run(t, state.ServiceVirtualIP{
+			Service:   psn,
+			IP:        net.ParseIP("240.0.0.2"),
+			RaftIndex: structs.RaftIndex{},
+		})
+	})
+	t.Run("pre-1.13.0 ServiceVirtualIP with ServiceName", func(t *testing.T) {
+		type compatServiceVirtualIP struct {
+			Service   structs.ServiceName
+			IP        net.IP
+			RaftIndex structs.RaftIndex
+		}
+
+		run(t, compatServiceVirtualIP{
+			Service: structs.ServiceName{
+				Name: "foo",
+			},
+			IP:        net.ParseIP("240.0.0.2"),
+			RaftIndex: structs.RaftIndex{},
+		})
+	})
+}

agent/structs/structs.go

@@ -2211,8 +2211,8 @@ type PeeredServiceName struct {
 }
 
 type ServiceName struct {
-	Name string
-	acl.EnterpriseMeta
+	Name               string
+	acl.EnterpriseMeta `mapstructure:",squash"`
 }
 
 func NewServiceName(name string, entMeta *acl.EnterpriseMeta) ServiceName {