migrate vtorc to use cobra commands (#13917)

Co-authored-by: Florent Poinsard <35779988+frouioui@users.noreply.github.com>

go/cmd/vtorc/cli/cli.go

@@ -0,0 +1,118 @@
+/*
+Copyright 2023 The Vitess 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 cli
+
+import (
+	"flag"
+	"fmt"
+
+	"github.com/spf13/cobra"
+
+	"vitess.io/vitess/go/acl"
+	_flag "vitess.io/vitess/go/internal/flag"
+	"vitess.io/vitess/go/viperutil"
+	viperdebug "vitess.io/vitess/go/viperutil/debug"
+	"vitess.io/vitess/go/vt/log"
+	"vitess.io/vitess/go/vt/servenv"
+	"vitess.io/vitess/go/vt/vtorc/config"
+	"vitess.io/vitess/go/vt/vtorc/inst"
+	"vitess.io/vitess/go/vt/vtorc/logic"
+	"vitess.io/vitess/go/vt/vtorc/server"
+)
+
+var (
+	configFile string
+	Main       = &cobra.Command{
+		Use:     "vtorc",
+		Short:   "", // TODO
+		Args:    cobra.NoArgs,
+		Version: servenv.AppVersion.String(),
+		PreRunE: func(cmd *cobra.Command, args []string) error {
+			_flag.TrickGlog()
+
+			watchCancel, err := viperutil.LoadConfig()
+			if err != nil {
+				return fmt.Errorf("%s: failed to read in config: %s", cmd.Name(), err)
+			}
+
+			servenv.OnTerm(watchCancel)
+			servenv.HTTPHandleFunc("/debug/config", viperdebug.HandlerFunc)
+			return nil
+		},
+		Run: run,
+	}
+)
+
+func run(cmd *cobra.Command, args []string) {
+	servenv.Init()
+	config.UpdateConfigValuesFromFlags()
+	inst.RegisterStats()
+
+	log.Info("starting vtorc")
+	if len(configFile) > 0 {
+		config.ForceRead(configFile)
+	} else {
+		config.Read("/etc/vtorc.conf.json", "conf/vtorc.conf.json", "vtorc.conf.json")
+	}
+	if config.Config.AuditToSyslog {
+		inst.EnableAuditSyslog()
+	}
+	config.MarkConfigurationLoaded()
+
+	// Log final config values to debug if something goes wrong.
+	config.LogConfigValues()
+	server.StartVTOrcDiscovery()
+
+	server.RegisterVTOrcAPIEndpoints()
+	servenv.OnRun(func() {
+		addStatusParts()
+	})
+
+	// For backward compatability, we require that VTOrc functions even when the --port flag is not provided.
+	// In this case, it should function like before but without the servenv pages.
+	// Therefore, currently we don't check for the --port flag to be necessary, but release 16+ that check
+	// can be added to always have the serenv page running in VTOrc.
+	servenv.RunDefault()
+}
+
+// addStatusParts adds UI parts to the /debug/status page of VTOrc
+func addStatusParts() {
+	servenv.AddStatusPart("Recent Recoveries", logic.TopologyRecoveriesTemplate, func() any {
+		recoveries, _ := logic.ReadRecentRecoveries(false, 0)
+		return recoveries
+	})
+}
+
+func init() {
+	servenv.RegisterDefaultFlags()
+	servenv.RegisterFlags()
+
+	Main.Flags().AddFlagSet(servenv.GetFlagSetFor("vtorc"))
+
+	// glog flags, no better way to do this
+	_flag.PreventGlogVFlagFromClobberingVersionFlagShorthand(Main.Flags())
+	Main.Flags().AddGoFlag(flag.Lookup("logtostderr"))
+	Main.Flags().AddGoFlag(flag.Lookup("alsologtostderr"))
+	Main.Flags().AddGoFlag(flag.Lookup("stderrthreshold"))
+	Main.Flags().AddGoFlag(flag.Lookup("log_dir"))
+
+	logic.RegisterFlags(Main.Flags())
+	server.RegisterFlags(Main.Flags())
+	config.RegisterFlags(Main.Flags())
+	acl.RegisterFlags(Main.Flags())
+	Main.Flags().StringVar(&configFile, "config", "", "config file name")
+}

go/cmd/vtorc/plugin_consultopo.go → go/cmd/vtorc/cli/plugin_consultopo.go

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package main
+package cli
 
 // This plugin imports consultopo to register the consul implementation of TopoServer.
 

go/cmd/vtorc/plugin_etcd2topo.go → go/cmd/vtorc/cli/plugin_etcd2topo.go

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package main
+package cli
 
 // This plugin imports etcd2topo to register the etcd2 implementation of TopoServer.
 

go/cmd/vtorc/plugin_grpctmclient.go → go/cmd/vtorc/cli/plugin_grpctmclient.go

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package main
+package cli
 
 // Imports and register the gRPC tabletmanager client
 

go/cmd/vtorc/plugin_prometheusbackend.go → go/cmd/vtorc/cli/plugin_prometheusbackend.go

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package main
+package cli
 
 // This plugin imports Prometheus to allow for instrumentation
 // with the Prometheus client library

go/cmd/vtorc/plugin_zk2topo.go → go/cmd/vtorc/cli/plugin_zk2topo.go

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package main
+package cli
 
 // Imports and register the zk2 TopologyServer
 

go/cmd/vtorc/docgen/main.go

@@ -0,0 +1,37 @@
+/*
+Copyright 2023 The Vitess 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 main
+
+import (
+	"github.com/spf13/cobra"
+
+	"vitess.io/vitess/go/cmd/internal/docgen"
+	"vitess.io/vitess/go/cmd/vtorc/cli"
+)
+
+func main() {
+	var dir string
+	cmd := cobra.Command{
+		Use: "docgen [-d <dir>]",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return docgen.GenerateMarkdownTree(cli.Main, dir)
+		},
+	}
+
+	cmd.Flags().StringVarP(&dir, "dir", "d", "doc", "output directory to write documentation")
+	_ = cmd.Execute()
+}

go/cmd/vtorc/main.go

@@ -17,120 +17,18 @@
 package main
 
 import (
-	"strings"
-
 	_ "github.com/go-sql-driver/mysql"
-	"github.com/spf13/pflag"
 	_ "modernc.org/sqlite"
 
-	"vitess.io/vitess/go/acl"
+	"vitess.io/vitess/go/cmd/vtorc/cli"
 	"vitess.io/vitess/go/vt/log"
-	"vitess.io/vitess/go/vt/servenv"
-	"vitess.io/vitess/go/vt/vtorc/config"
-	"vitess.io/vitess/go/vt/vtorc/inst"
-	"vitess.io/vitess/go/vt/vtorc/logic"
-	"vitess.io/vitess/go/vt/vtorc/server"
 )
 
-// transformArgsForPflag turns a slice of raw args passed on the command line,
-// possibly incompatible with pflag (because the user is expecting stdlib flag
-// parsing behavior) and transforms them into the arguments that should have
-// been passed to conform to pflag parsing behavior.
-//
-// the primary function is to catch any cases where the user specified a longopt
-// with only a single hyphen (e.g. `-myflag`) and correct it to be
-// double-hyphenated.
-//
-// note that this transformation does _not_ actually validate the arguments; for
-// example if the user specifies `--myflag`, but the FlagSet has no such flag
-// defined, that will still appear in the returned result and will (correctly)
-// cause a parse error later on in `main`, at which point the CLI usage will
-// be printed.
-//
-// note also that this transformation is incomplete. pflag allows interspersing
-// of flag and positional arguments, whereas stdlib flag does not. however, for
-// vtorc specifically, with the exception of `vtorc help <topic>`, the CLI only
-// consumes flag arguments (in other words, there are no supported subcommands),
-// so this is a non-issue, and is not implemented here in order to make this
-// function a bit simpler.
-func transformArgsForPflag(fs *pflag.FlagSet, args []string) (result []string) {
-	for i, arg := range args {
-		switch {
-		case arg == "--":
-			// pflag stops parsing at `--`, so we're done transforming the CLI
-			// arguments. Just append everything remaining and be done.
-			result = append(result, args[i:]...)
-			return result
-		case strings.HasPrefix(arg, "--"):
-			// Long-hand flag. Append it and continue.
-			result = append(result, arg)
-		case strings.HasPrefix(arg, "-"):
-			// Most complex case. This is either:
-			// 1. A legacy long-hand flag that needs a double-dash (e.g. `-myflag` => `--myflag`).
-			// 2. One _or more_ pflag shortopts all shoved together (think `rm -rf` as `rm -r -f`).
-			//
-			// In the latter case, we don't need to do any transformations, but
-			// in the former, we do.
-			name := strings.SplitN(arg[1:], "=", 2)[0] // discard any potential value (`-myflag` and `-myflag=10` both have the name of `myflag`)
-			if fs.Lookup(name) != nil || name == "help" {
-				// Case 1: We have a long opt with this name, so we need to
-				// prepend an additional hyphen.
-				result = append(result, "-"+arg)
-			} else {
-				// Case 2: No transformation needed.
-				result = append(result, arg)
-			}
-		default:
-			// Just a flag argument. Nothing to transform.
-			result = append(result, arg)
-		}
-	}
-
-	return result
-}
-
 // main is the application's entry point. It will spawn an HTTP interface.
 func main() {
-	servenv.RegisterDefaultFlags()
-	servenv.RegisterFlags()
-
-	var configFile string
-	servenv.OnParseFor("vtorc", func(fs *pflag.FlagSet) {
-		logic.RegisterFlags(fs)
-		server.RegisterFlags(fs)
-		config.RegisterFlags(fs)
-		acl.RegisterFlags(fs)
+	// TODO: viperutil.BindFlags()
 
-		fs.StringVar(&configFile, "config", "", "config file name")
-	})
-	servenv.ParseFlags("vtorc")
-	servenv.Init()
-	config.UpdateConfigValuesFromFlags()
-	inst.RegisterStats()
-
-	log.Info("starting vtorc")
-	if len(configFile) > 0 {
-		config.ForceRead(configFile)
-	} else {
-		config.Read("/etc/vtorc.conf.json", "conf/vtorc.conf.json", "vtorc.conf.json")
-	}
-	if config.Config.AuditToSyslog {
-		inst.EnableAuditSyslog()
+	if err := cli.Main.Execute(); err != nil {
+		log.Exit(err)
 	}
-	config.MarkConfigurationLoaded()
-
-	// Log final config values to debug if something goes wrong.
-	config.LogConfigValues()
-	server.StartVTOrcDiscovery()
-
-	server.RegisterVTOrcAPIEndpoints()
-	servenv.OnRun(func() {
-		addStatusParts()
-	})
-
-	// For backward compatability, we require that VTOrc functions even when the --port flag is not provided.
-	// In this case, it should function like before but without the servenv pages.
-	// Therefore, currently we don't check for the --port flag to be necessary, but release 16+ that check
-	// can be added to always have the serenv page running in VTOrc.
-	servenv.RunDefault()
 }