server: --enable-v2 and --enable-v2v3 is decomissioned

etcd.conf.yml.sample

@@ -69,9 +69,6 @@ initial-cluster-state: 'new'
 # Reject reconfiguration requests that would cause quorum loss.
 strict-reconfig-check: false
 
-# Accept etcd V2 client requests
-enable-v2: true
-
 # Enable runtime profiling data via HTTP server
 enable-pprof: true
 

server/embed/config.go

@@ -86,9 +86,6 @@ const (
 	// DefaultStrictReconfigCheck is the default value for "--strict-reconfig-check" flag.
 	// It's enabled by default.
 	DefaultStrictReconfigCheck = true
-	// DefaultEnableV2 is the default value for "--enable-v2" flag.
-	// v2 API is disabled by default.
-	DefaultEnableV2 = false
 
 	// maxElectionMs specifies the maximum value of election timeout.
 	// More details are listed in ../Documentation/tuning.md#time-parameters.
@@ -224,11 +221,6 @@ type Config struct {
 	InitialClusterToken   string `json:"initial-cluster-token"`
 	StrictReconfigCheck   bool   `json:"strict-reconfig-check"`
 
-	// EnableV2 exposes the deprecated V2 API surface.
-	// TODO: Delete in 3.6 (https://github.com/etcd-io/etcd/issues/12913)
-	// Deprecated in 3.5.
-	EnableV2 bool `json:"enable-v2"`
-
 	// AutoCompactionMode is either 'periodic' or 'revision'.
 	AutoCompactionMode string `json:"auto-compaction-mode"`
 	// AutoCompactionRetention is either duration string with time unit
@@ -311,10 +303,6 @@ type Config struct {
 
 	ExperimentalInitialCorruptCheck bool          `json:"experimental-initial-corrupt-check"`
 	ExperimentalCorruptCheckTime    time.Duration `json:"experimental-corrupt-check-time"`
-	// ExperimentalEnableV2V3 configures URLs that expose deprecated V2 API working on V3 store.
-	// Deprecated in v3.5.
-	// TODO: Delete in v3.6 (https://github.com/etcd-io/etcd/issues/12913)
-	ExperimentalEnableV2V3 string `json:"experimental-enable-v2v3"`
 	// ExperimentalEnableLeaseCheckpoint enables leader to send regular checkpoints to other members to prevent reset of remaining TTL on leader change.
 	ExperimentalEnableLeaseCheckpoint bool `json:"experimental-enable-lease-checkpoint"`
 	// ExperimentalEnableLeaseCheckpointPersist enables persisting remainingTTL to prevent indefinite auto-renewal of long lived leases. Always enabled in v3.6. Should be used to ensure smooth upgrade from v3.5 clusters with this feature enabled.
@@ -488,7 +476,6 @@ func NewConfig() *Config {
 
 		StrictReconfigCheck: DefaultStrictReconfigCheck,
 		Metrics:             "basic",
-		EnableV2:            DefaultEnableV2,
 
 		CORS:          map[string]struct{}{"*": {}},
 		HostWhitelist: map[string]struct{}{"*": {}},

server/embed/etcd.go

@@ -38,9 +38,6 @@ import (
 	"go.etcd.io/etcd/server/v3/etcdserver"
 	"go.etcd.io/etcd/server/v3/etcdserver/api/etcdhttp"
 	"go.etcd.io/etcd/server/v3/etcdserver/api/rafthttp"
-	"go.etcd.io/etcd/server/v3/etcdserver/api/v2http"
-	"go.etcd.io/etcd/server/v3/etcdserver/api/v2v3"
-	"go.etcd.io/etcd/server/v3/etcdserver/api/v3client"
 	"go.etcd.io/etcd/server/v3/etcdserver/api/v3rpc"
 	"go.etcd.io/etcd/server/v3/storage"
 	"go.etcd.io/etcd/server/v3/verify"
@@ -695,25 +692,9 @@ func (e *Etcd) serveClients() (err error) {
 	}
 
 	// Start a client server goroutine for each listen address
-	var h http.Handler
-	if e.Config().EnableV2 {
-		if e.Config().V2DeprecationEffective().IsAtLeast(config.V2_DEPR_1_WRITE_ONLY) {
-			return fmt.Errorf("--enable-v2 and --v2-deprecation=%s are mutually exclusive", e.Config().V2DeprecationEffective())
-		}
-		e.cfg.logger.Warn("Flag `enable-v2` is deprecated and will get removed in etcd 3.6.")
-		if len(e.Config().ExperimentalEnableV2V3) > 0 {
-			e.cfg.logger.Warn("Flag `experimental-enable-v2v3` is deprecated and will get removed in etcd 3.6.")
-			srv := v2v3.NewServer(e.cfg.logger, v3client.New(e.Server), e.cfg.ExperimentalEnableV2V3)
-			h = v2http.NewClientHandler(e.GetLogger(), srv, e.Server.Cfg.ReqTimeout())
-		} else {
-			h = v2http.NewClientHandler(e.GetLogger(), e.Server, e.Server.Cfg.ReqTimeout())
-		}
-	} else {
-		mux := http.NewServeMux()
-		etcdhttp.HandleBasic(e.cfg.logger, mux, e.Server)
-		etcdhttp.HandleMetricsHealthForV3(e.cfg.logger, mux, e.Server)
-		h = mux
-	}
+	mux := http.NewServeMux()
+	etcdhttp.HandleBasic(e.cfg.logger, mux, e.Server)
+	etcdhttp.HandleMetricsHealthForV3(e.cfg.logger, mux, e.Server)
 
 	gopts := []grpc.ServerOption{}
 	if e.cfg.GRPCKeepAliveMinTime > time.Duration(0) {
@@ -733,7 +714,7 @@ func (e *Etcd) serveClients() (err error) {
 	// start client servers in each goroutine
 	for _, sctx := range e.sctxs {
 		go func(s *serveCtx) {
-			e.errHandler(s.serve(e.Server, &e.cfg.ClientTLSInfo, h, e.errHandler, gopts...))
+			e.errHandler(s.serve(e.Server, &e.cfg.ClientTLSInfo, mux, e.errHandler, gopts...))
 		}(sctx)
 	}
 	return nil

server/etcdmain/config.go

@@ -200,8 +200,6 @@ func newConfig() *config {
 
 	fs.BoolVar(&cfg.ec.PreVote, "pre-vote", cfg.ec.PreVote, "Enable to run an additional Raft election phase.")
 
-	fs.BoolVar(&cfg.ec.EnableV2, "enable-v2", cfg.ec.EnableV2, "Accept etcd V2 client requests. Deprecated in v3.5. Will be decommission in v3.6.")
-	fs.StringVar(&cfg.ec.ExperimentalEnableV2V3, "experimental-enable-v2v3", cfg.ec.ExperimentalEnableV2V3, "v3 prefix for serving emulated v2 state. Deprecated in 3.5. Will be decommissioned in 3.6.")
 	fs.Var(cfg.cf.v2deprecation, "v2-deprecation", fmt.Sprintf("v2store deprecation stage: %q. ", cfg.cf.proxy.Valids()))
 
 	// proxy

server/etcdmain/help.go

@@ -123,8 +123,6 @@ Clustering:
     Auto compaction retention length. 0 means disable auto compaction.
   --auto-compaction-mode 'periodic'
     Interpret 'auto-compaction-retention' one of: periodic|revision. 'periodic' for duration based retention, defaulting to hours if no time unit is provided (e.g. '5m'). 'revision' for revision number based retention.
-  --enable-v2 '` + strconv.FormatBool(embed.DefaultEnableV2) + `'
-    Accept etcd V2 client requests. Deprecated and to be decommissioned in v3.6.
   --v2-deprecation '` + string(cconfig.V2_DEPR_DEFAULT) + `'
     Phase of v2store deprecation. Allows to opt-in for higher compatibility mode.
     Supported values:
@@ -234,8 +232,6 @@ Experimental feature:
     Enable to check data corruption before serving any client/peer traffic.
   --experimental-corrupt-check-time '0s'
     Duration of time between cluster corruption check passes.
-  --experimental-enable-v2v3 ''
-    Serve v2 requests through the v3 backend under a given prefix. Deprecated and to be decommissioned in v3.6.
   --experimental-enable-lease-checkpoint 'false'
     ExperimentalEnableLeaseCheckpoint enables primary lessor to persist lease remainingTTL to prevent indefinite auto-renewal of long lived leases.
   --experimental-compaction-batch-limit 1000