tests: Add tests for HashByRev HTTP API

Signed-off-by: Marek Siarkowicz <siarkowicz@google.com>

server/etcdserver/corrupt.go

@@ -277,6 +277,7 @@ func (s *EtcdServer) getPeerHashKVs(rev int64) []*peerHashKVResp {
 
 	lg := s.Logger()
 
+	cc := &http.Client{Transport: s.peerRt}
 	var resps []*peerHashKVResp
 	for _, p := range peers {
 		if len(p.eps) == 0 {
@@ -287,7 +288,7 @@ func (s *EtcdServer) getPeerHashKVs(rev int64) []*peerHashKVResp {
 		var lastErr error
 		for _, ep := range p.eps {
 			ctx, cancel := context.WithTimeout(context.Background(), s.Cfg.ReqTimeout())
-			resp, lastErr := s.getPeerHashKVHTTP(ctx, ep, rev)
+			resp, lastErr := HashByRev(ctx, cc, ep, rev)
 			cancel()
 			if lastErr == nil {
 				resps = append(resps, &peerHashKVResp{peerInfo: p, resp: resp, err: nil})
@@ -368,9 +369,8 @@ func (h *hashKVHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	w.Write(respBytes)
 }
 
-// getPeerHashKVHTTP fetch hash of kv store at the given rev via http call to the given url
-func (s *EtcdServer) getPeerHashKVHTTP(ctx context.Context, url string, rev int64) (*pb.HashKVResponse, error) {
-	cc := &http.Client{Transport: s.peerRt}
+// HashByRev fetch hash of kv store at the given rev via http call to the given url
+func HashByRev(ctx context.Context, cc *http.Client, url string, rev int64) (*pb.HashKVResponse, error) {
 	hashReq := &pb.HashKVRequest{Revision: rev}
 	hashReqBytes, err := json.Marshal(hashReq)
 	if err != nil {

tests/integration/hashkv_test.go

@@ -0,0 +1,109 @@
+// Copyright 2022 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package integration
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/http"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	clientv3 "go.etcd.io/etcd/client/v3"
+	"go.etcd.io/etcd/server/v3/etcdserver"
+	integration2 "go.etcd.io/etcd/tests/v3/framework/integration"
+)
+
+const (
+	// Use high prime
+	compactionCycle = 71
+)
+
+func TestCompactionHashHTTP(t *testing.T) {
+	integration2.BeforeTest(t)
+
+	clus := integration2.NewCluster(t, &integration2.ClusterConfig{Size: 1})
+	defer clus.Terminate(t)
+
+	ctx := context.Background()
+	cc, err := clus.ClusterClient()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var totalRevisions int64 = 1210
+	assert.Less(t, int64(1000), totalRevisions)
+	assert.Less(t, int64(compactionCycle*10), totalRevisions)
+	var rev int64
+	client := &http.Client{
+		Transport: &http.Transport{
+			DialContext: func(_ context.Context, _, _ string) (net.Conn, error) {
+				return net.Dial("unix", clus.Members[0].PeerURLs[0].Host)
+			},
+		},
+	}
+	for ; rev < totalRevisions; rev += compactionCycle {
+		testCompactionHash(ctx, t, cc, client, rev, rev+compactionCycle)
+	}
+	testCompactionHash(ctx, t, cc, client, rev, rev+totalRevisions)
+}
+
+func testCompactionHash(ctx context.Context, t *testing.T, cc *clientv3.Client, client *http.Client, start, stop int64) {
+	for i := start; i <= stop; i++ {
+		cc.Put(ctx, pickKey(i), fmt.Sprint(i))
+	}
+	hash1, err := etcdserver.HashByRev(ctx, client, "http://unix", stop)
+	assert.NoError(t, err, "error on rev %v", stop)
+
+	_, err = cc.Compact(ctx, stop)
+	assert.NoError(t, err, "error on compact rev %v", stop)
+
+	// Wait for compaction to be compacted
+	time.Sleep(50 * time.Millisecond)
+
+	hash2, err := etcdserver.HashByRev(ctx, client, "http://unix", stop)
+	assert.NoError(t, err, "error on rev %v", stop)
+	assert.Equal(t, hash1, hash2, "hashes do not match on rev %v", stop)
+}
+
+func pickKey(i int64) string {
+	if i%(compactionCycle*2) == 30 {
+		return "zenek"
+	}
+	if i%compactionCycle == 30 {
+		return "xavery"
+	}
+	// Use low prime number to ensure repeats without alignment
+	switch i % 7 {
+	case 0:
+		return "alice"
+	case 1:
+		return "bob"
+	case 2:
+		return "celine"
+	case 3:
+		return "dominik"
+	case 4:
+		return "eve"
+	case 5:
+		return "frederica"
+	case 6:
+		return "gorge"
+	default:
+		panic("Can't count")
+	}
+}