add extra resiliency to snapshot restore test (#16712)

test/integration/consul-container/test/snapshot/snapshot_restore_test.go

@@ -3,6 +3,7 @@ package snapshot
 import (
 	"fmt"
 	"github.com/hashicorp/consul/api"
+	"github.com/hashicorp/consul/sdk/testutil/retry"
 	libcluster "github.com/hashicorp/consul/test/integration/consul-container/libs/cluster"
 	libtopology "github.com/hashicorp/consul/test/integration/consul-container/libs/topology"
 	"github.com/hashicorp/consul/test/integration/consul-container/libs/utils"
@@ -79,13 +80,27 @@ func testSnapShotRestoreForLogStore(t *testing.T, logStore libcluster.LogStore)
 
 	libcluster.WaitForLeader(t, cluster2, client2)
 
+	leader, err := cluster2.Leader()
+	require.NoError(t, err)
+
 	followers, err := cluster2.Followers()
 	require.NoError(t, err)
 	require.Len(t, followers, 2)
 
 	// use a follower api client and set `AllowStale` to true
 	// to test the follower snapshot install code path as well.
 	fc := followers[0].GetClient()
+	lc := leader.GetClient()
+
+	retry.Run(t, func(r *retry.R) {
+		self, err := lc.Agent().Self()
+		require.NoError(r, err)
+		LeaderLogIndex := self["Stats"]["raft"].(map[string]interface{})["last_log_index"].(string)
+		self, err = fc.Agent().Self()
+		require.NoError(r, err)
+		followerLogIndex := self["Stats"]["raft"].(map[string]interface{})["last_log_index"].(string)
+		require.Equal(r, LeaderLogIndex, followerLogIndex)
+	})
 
 	for i := 0; i < 100; i++ {
 		kv, _, err := fc.KV().Get(fmt.Sprintf("key-%d", i), &api.QueryOptions{AllowStale: true})