test: Add test for global rate limiting with load balancing

functional_test.go

@@ -25,6 +25,7 @@ import (
 	"os"
 	"strings"
 	"testing"
+	"time"
 
 	guber "github.com/mailgun/gubernator/v2"
 	"github.com/mailgun/gubernator/v2/cluster"
@@ -34,6 +35,10 @@ import (
 	"github.com/prometheus/common/model"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/resolver"
 	json "google.golang.org/protobuf/encoding/protojson"
 )
 
@@ -859,6 +864,62 @@ func TestGlobalRateLimits(t *testing.T) {
 	})
 }
 
+func TestGlobalRateLimitsWithLoadBalancing(t *testing.T) {
+	owner := cluster.PeerAt(2).GRPCAddress
+	peer := cluster.PeerAt(0).GRPCAddress
+	assert.NotEqual(t, owner, peer)
+
+	dialOpts := []grpc.DialOption{
+		grpc.WithResolvers(newStaticBuilder()),
+		grpc.WithTransportCredentials(insecure.NewCredentials()),
+		grpc.WithDefaultServiceConfig(`{"loadBalancingConfig": [{"round_robin":{}}]}`),
+	}
+
+	address := fmt.Sprintf("static:///%s,%s", owner, peer)
+	conn, err := grpc.DialContext(context.Background(), address, dialOpts...)
+	require.NoError(t, err)
+
+	client := guber.NewV1Client(conn)
+
+	sendHit := func(status guber.Status, assertion func(resp *guber.RateLimitResp), i int) string {
+		ctx, cancel := context.WithTimeout(context.Background(), clock.Hour*5)
+		defer cancel()
+		resp, err := client.GetRateLimits(ctx, &guber.GetRateLimitsReq{
+			Requests: []*guber.RateLimitReq{
+				{
+					Name:      "test_global",
+					UniqueKey: "account:12345",
+					Algorithm: guber.Algorithm_LEAKY_BUCKET,
+					Behavior:  guber.Behavior_GLOBAL,
+					Duration:  guber.Minute * 5,
+					Hits:      1,
+					Limit:     2,
+				},
+			},
+		})
+		require.NoError(t, err, i)
+		gotResp := resp.Responses[0]
+		assert.Equal(t, "", gotResp.GetError(), i)
+		assert.Equal(t, status, gotResp.GetStatus(), i)
+
+		if assertion != nil {
+			assertion(gotResp)
+		}
+
+		return gotResp.GetMetadata()["owner"]
+	}
+
+	// Send two hits that should be processed by the owner and the peer and deplete the limit
+	sendHit(guber.Status_UNDER_LIMIT, nil, 1)
+	sendHit(guber.Status_UNDER_LIMIT, nil, 2)
+	// sleep to ensure the async forward has occurred and state should be shared
+	time.Sleep(time.Second * 5)
+
+	for i := 0; i < 10; i++ {
+		sendHit(guber.Status_OVER_LIMIT, nil, i+2)
+	}
+}
+
 func getMetricRequest(t testutil.TestingT, url string, name string) *model.Sample {
 	resp, err := http.Get(url)
 	require.NoError(t, err)
@@ -1273,3 +1334,46 @@ func getMetric(t testutil.TestingT, in io.Reader, name string) *model.Sample {
 	}
 	return nil
 }
+
+// staticBuilder implements the `resolver.Builder` interface.
+type staticBuilder struct{}
+
+func newStaticBuilder() resolver.Builder {
+	return &staticBuilder{}
+}
+
+func (sb *staticBuilder) Build(target resolver.Target, cc resolver.ClientConn, _ resolver.BuildOptions) (resolver.Resolver, error) {
+	var resolverAddrs []resolver.Address
+	for _, address := range strings.Split(target.Endpoint(), ",") {
+		resolverAddrs = append(resolverAddrs, resolver.Address{
+			Addr:       address,
+			ServerName: address,
+		})
+
+	}
+	r, err := newStaticResolver(cc, resolverAddrs)
+	if err != nil {
+		return nil, err
+	}
+	return r, nil
+}
+
+func (sb *staticBuilder) Scheme() string {
+	return "static"
+}
+
+type staticResolver struct {
+	cc resolver.ClientConn
+}
+
+func newStaticResolver(cc resolver.ClientConn, addresses []resolver.Address) (resolver.Resolver, error) {
+	err := cc.UpdateState(resolver.State{Addresses: addresses})
+	if err != nil {
+		return nil, err
+	}
+	return &staticResolver{cc: cc}, nil
+}
+
+func (sr *staticResolver) ResolveNow(_ resolver.ResolveNowOptions) {}
+
+func (sr *staticResolver) Close() {}