Remove explicit usage of etcd v2 (api and storage)

changelog/18.0/18.0.0/summary.md

@@ -4,6 +4,7 @@
 
 - **[Major Changes](#major-changes)**
   - **[Breaking Changes](#breaking-changes)**
+    - [Local examples now use etcd v3 storage and API](#local-examples-etcd-v3)
   - **[New command line flags and behavior](#new-flag)**
     - [VTOrc flag `--allow-emergency-reparent`](#new-flag-toggle-ers)
     - [ERS sub flag `--wait-for-all-tablets`](#new-ers-subflag)
@@ -26,6 +27,14 @@
 
 ### <a id="breaking-changes"/>Breaking Changes
 
+#### <a id="local-examples-etcd-v3"/>Local examples now use etcd v3 storage and API
+In previous releases the [local examples](https://github.com/vitessio/vitess/tree/main/examples/local) were
+explicitly using etcd v2 storage (`etcd --enable-v2=true`) and API (`ETCDCTL_API=2`) mode. We have now
+removed this legacy etcd usage and instead use the new (default) etcd v3 storage and API. Please see
+[PR #13791](https://github.com/vitessio/vitess/pull/13791) for additional info. If you are using the local
+examples in any sort of long-term non-testing capacity, then you will need to explicitly use the v2 storage
+and API mode or [migrate your existing data from v2 to v3](https://etcd.io/docs/v3.5/tutorials/how-to-migrate/).
+
 ### <a id="new-flag"/>New command line flags and behavior
 
 #### <a id="new-flag-toggle-ers"/>VTOrc flag `--allow-emergency-reparent`

examples/common/scripts/etcd-up.sh

@@ -19,22 +19,15 @@
 source "$(dirname "${BASH_SOURCE[0]:-$0}")/../env.sh"
 
 cell=${CELL:-'test'}
-export ETCDCTL_API=2
 
 # Check that etcd is not already running
 curl "http://${ETCD_SERVER}" > /dev/null 2>&1 && fail "etcd is already running. Exiting."
 
-etcd --enable-v2=true --data-dir "${VTDATAROOT}/etcd/"  --listen-client-urls "http://${ETCD_SERVER}" --advertise-client-urls "http://${ETCD_SERVER}" > "${VTDATAROOT}"/tmp/etcd.out 2>&1 &
+etcd --data-dir "${VTDATAROOT}/etcd/"  --listen-client-urls "http://${ETCD_SERVER}" --advertise-client-urls "http://${ETCD_SERVER}" > "${VTDATAROOT}"/tmp/etcd.out 2>&1 &
 PID=$!
 echo $PID > "${VTDATAROOT}/tmp/etcd.pid"
 sleep 5
 
-echo "add /vitess/global"
-etcdctl --endpoints "http://${ETCD_SERVER}" mkdir /vitess/global &
-
-echo "add /vitess/$cell"
-etcdctl --endpoints "http://${ETCD_SERVER}" mkdir /vitess/$cell &
-
 # And also add the CellInfo description for the cell.
 # If the node already exists, it's fine, means we used existing data.
 echo "add $cell CellInfo"

go/test/endtoend/cluster/topo_process.go

@@ -17,8 +17,10 @@ limitations under the License.
 package cluster
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
+	"net"
 	"net/http"
 	"os"
 	"os/exec"
@@ -27,7 +29,10 @@ import (
 	"syscall"
 	"time"
 
+	clientv3 "go.etcd.io/etcd/client/v3"
+
 	"vitess.io/vitess/go/vt/log"
+	vtopo "vitess.io/vitess/go/vt/topo"
 )
 
 // TopoProcess is a generic handle for a running Topo service .
@@ -44,6 +49,7 @@ type TopoProcess struct {
 	VerifyURL          string
 	PeerURL            string
 	ZKPorts            string
+	Client             interface{}
 
 	proc *exec.Cmd
 	exit chan error
@@ -57,10 +63,9 @@ func (topo *TopoProcess) Setup(topoFlavor string, cluster *LocalProcessCluster)
 	case "consul":
 		return topo.SetupConsul(cluster)
 	default:
-		// We still rely on the etcd v2 API for things like mkdir.
-		// If this ENV var is not set then some tests may fail with etcd 3.4+
-		// where the v2 API is disabled by default in both the client and server.
-		os.Setenv("ETCDCTL_API", "2")
+		// Override any inherited ETCDCTL_API env value to
+		// ensure that we use the v3 API and storage.
+		os.Setenv("ETCDCTL_API", "3")
 		return topo.SetupEtcd()
 	}
 }
@@ -77,7 +82,6 @@ func (topo *TopoProcess) SetupEtcd() (err error) {
 		"--initial-advertise-peer-urls", topo.PeerURL,
 		"--listen-peer-urls", topo.PeerURL,
 		"--initial-cluster", fmt.Sprintf("%s=%s", topo.Name, topo.PeerURL),
-		"--enable-v2=true",
 	)
 
 	err = createDirectory(topo.DataDirectory, 0700)
@@ -109,6 +113,14 @@ func (topo *TopoProcess) SetupEtcd() (err error) {
 	timeout := time.Now().Add(60 * time.Second)
 	for time.Now().Before(timeout) {
 		if topo.IsHealthy() {
+			cli, cerr := clientv3.New(clientv3.Config{
+				Endpoints:   []string{net.JoinHostPort(topo.Host, fmt.Sprintf("%d", topo.Port))},
+				DialTimeout: 5 * time.Second,
+			})
+			if cerr != nil {
+				return err
+			}
+			topo.Client = cli
 			return
 		}
 		select {
@@ -125,7 +137,6 @@ func (topo *TopoProcess) SetupEtcd() (err error) {
 // SetupZookeeper spawns a new zookeeper topo service and initializes it with the defaults.
 // The service is kept running in the background until TearDown() is called.
 func (topo *TopoProcess) SetupZookeeper(cluster *LocalProcessCluster) (err error) {
-
 	host, err := os.Hostname()
 	if err != nil {
 		return
@@ -171,7 +182,6 @@ type PortsInfo struct {
 // SetupConsul spawns a new consul service and initializes it with the defaults.
 // The service is kept running in the background until TearDown() is called.
 func (topo *TopoProcess) SetupConsul(cluster *LocalProcessCluster) (err error) {
-
 	topo.VerifyURL = fmt.Sprintf("http://%s:%d/v1/kv/?keys", topo.Host, topo.Port)
 
 	_ = os.MkdirAll(topo.LogDirectory, os.ModePerm)
@@ -247,8 +257,16 @@ func (topo *TopoProcess) SetupConsul(cluster *LocalProcessCluster) (err error) {
 	return fmt.Errorf("process '%s' timed out after 60s (err: %s)", topo.Binary, <-topo.exit)
 }
 
-// TearDown shutdowns the running topo service
+// TearDown shutdowns the running topo service.
 func (topo *TopoProcess) TearDown(Cell string, originalVtRoot string, currentRoot string, keepdata bool, topoFlavor string) error {
+	if topo.Client != nil {
+		switch cli := topo.Client.(type) {
+		case *clientv3.Client:
+			_ = cli.Close()
+		default:
+			log.Errorf("Unknown topo client type %T", cli)
+		}
+	}
 
 	if topoFlavor == "zk2" {
 		cmd := "shutdown"
@@ -324,6 +342,9 @@ func (topo *TopoProcess) ManageTopoDir(command string, directory string) (err er
 	url := topo.VerifyURL + directory
 	payload := strings.NewReader(`{"dir":"true"}`)
 	if command == "mkdir" {
+		if *topoFlavor == "etcd2" { // No need to create the empty prefix keys in v3
+			return nil
+		}
 		req, _ := http.NewRequest("PUT", url, payload)
 		req.Header.Add("content-type", "application/json")
 		resp, err := http.DefaultClient.Do(req)
@@ -332,6 +353,22 @@ func (topo *TopoProcess) ManageTopoDir(command string, directory string) (err er
 		}
 		return err
 	} else if command == "rmdir" {
+		if *topoFlavor == "etcd2" {
+			if topo.Client == nil {
+				return fmt.Errorf("etcd client is not initialized")
+			}
+			cli, ok := topo.Client.(*clientv3.Client)
+			if !ok {
+				return fmt.Errorf("etcd client is invalid")
+			}
+			ctx, cancel := context.WithTimeout(context.Background(), vtopo.RemoteOperationTimeout)
+			defer cancel()
+			_, err = cli.Delete(ctx, directory, clientv3.WithPrefix())
+			if err != nil {
+				return err
+			}
+			return nil
+		}
 		req, _ := http.NewRequest("DELETE", url+"?dir=true", payload)
 		resp, err := http.DefaultClient.Do(req)
 		if err == nil {
@@ -366,7 +403,7 @@ func TopoProcessInstance(port int, peerPort int, hostname string, flavor string,
 	topo.ListenClientURL = fmt.Sprintf("http://%s:%d", topo.Host, topo.Port)
 	topo.DataDirectory = path.Join(os.Getenv("VTDATAROOT"), fmt.Sprintf("%s_%d", "topo", port))
 	topo.LogDirectory = path.Join(os.Getenv("VTDATAROOT"), fmt.Sprintf("%s_%d", "topo", port), "logs")
-	topo.VerifyURL = fmt.Sprintf("http://%s:%d/v2/keys", topo.Host, topo.Port)
+	topo.VerifyURL = fmt.Sprintf("http://%s:%d/health", topo.Host, topo.Port)
 	topo.PeerURL = fmt.Sprintf("http://%s:%d", hostname, peerPort)
 	return topo
 }

go/test/endtoend/clustertest/etcd_test.go

@@ -18,15 +18,46 @@ package clustertest
 
 import (
 	"fmt"
+	"net"
 	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+	clientv3 "go.etcd.io/etcd/client/v3"
 
 	"vitess.io/vitess/go/test/endtoend/cluster"
 )
 
 func TestEtcdServer(t *testing.T) {
 	defer cluster.PanicHandler(t)
-	etcdURL := fmt.Sprintf("http://%s:%d/v2/keys", clusterInstance.Hostname, clusterInstance.TopoPort)
-	testURL(t, etcdURL, "generic etcd url")
-	testURL(t, etcdURL+"/vitess/global", "vitess global key")
-	testURL(t, etcdURL+"/vitess/zone1", "vitess zone1 key")
+
+	// Confirm the basic etcd cluster health.
+	etcdHealthURL := fmt.Sprintf("http://%s:%d/health", clusterInstance.Hostname, clusterInstance.TopoPort)
+	testURL(t, etcdHealthURL, "generic etcd health url")
+
+	// Confirm that we have a working topo server by looking for some
+	// expected keys.
+	etcdClientOptions := []clientv3.OpOption{
+		clientv3.WithPrefix(),
+		clientv3.WithKeysOnly(),
+		clientv3.WithLimit(1),
+	}
+	cli, err := clientv3.New(clientv3.Config{
+		Endpoints:   []string{net.JoinHostPort(clusterInstance.TopoProcess.Host, fmt.Sprintf("%d", clusterInstance.TopoProcess.Port))},
+		DialTimeout: 5 * time.Second,
+	})
+	require.NoError(t, err)
+	defer cli.Close()
+	keyPrefixes := []string{
+		// At a minimum, this prefix confirms that we have a functioning
+		// global topo server with a valid cell from the test env.
+		fmt.Sprintf("/vitess/global/cells/%s", cell),
+	}
+	for _, keyPrefix := range keyPrefixes {
+		res, err := cli.Get(cli.Ctx(), keyPrefix, etcdClientOptions...)
+		require.NoError(t, err)
+		require.NotNil(t, res)
+		// Confirm that we have at least one key matching the prefix.
+		require.Greaterf(t, len(res.Kvs), 0, "no keys found matching prefix: %s", keyPrefix)
+	}
 }