replicaset downgrade: make version a positional argument

Closes #1073

@TarantoolBot
title: replicaset downgrade: make version a positional argument

CHANGELOG.md

@@ -29,6 +29,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - `tt coredump pack`: if `-e` option is omitted first search tarantool
   executable in tt environment then in `PATH` instead of using the hardcoded
   path `/usr/bin/tarantool`.
+- `tt replicaset downgrade`: make version a positional argument rather than
+  using the mandatory option `-v` (`--version`).
 
 ### Fixed
 

cli/cmd/replicaset.go

@@ -3,7 +3,6 @@ package cmd
 import (
 	"errors"
 	"fmt"
-	"os"
 	"regexp"
 	"strings"
 
@@ -51,7 +50,6 @@ var (
 
 	chosenReplicasetAliases []string
 	lsnTimeout              int
-	downgradeVersion        string
 
 	replicasetUriHelp = "  The URI can be specified in the following formats:\n" +
 		"  * [tcp://][username:password@][host:port]\n" +
@@ -90,33 +88,33 @@ func newUpgradeCmd() *cobra.Command {
 
 // newDowngradeCmd creates a "replicaset downgrade" command.
 func newDowngradeCmd() *cobra.Command {
+	validateVersion := func(i int) cobra.PositionalArgs {
+		return func(cmd *cobra.Command, args []string) error {
+			var versionPattern = regexp.MustCompile(`^\d+\.\d+\.\d+$`)
+			if args[i] == "" {
+				return errors.New("need to specify the version to downgrade to")
+			} else if !versionPattern.MatchString(args[i]) {
+				return errors.New("version must be in the format " +
+					"'x.x.x', where x is a number")
+			}
+			return nil
+		}
+	}
+
 	cmd := &cobra.Command{
-		Use: "downgrade (<APP_NAME> | <URI>) [flags]\n\n" +
+		Use: "downgrade (<APP_NAME> | <URI>) VERSION [flags]\n\n" +
 			replicasetUriHelp,
 		DisableFlagsInUseLine: true,
 		Short:                 "Downgrade tarantool cluster",
 		Long: "Downgrade tarantool cluster.\n\n" +
 			libconnect.EnvCredentialsHelp + "\n\n",
 		Run: func(cmd *cobra.Command, args []string) {
-			var versionPattern = regexp.MustCompile(`^\d+\.\d+\.\d+$`)
-			if downgradeVersion == "" {
-				err := errors.New("need to specify the version to downgrade " +
-					"use --version (-v) option")
-				util.HandleCmdErr(cmd, err)
-				os.Exit(1)
-			} else if !versionPattern.MatchString(downgradeVersion) {
-				err := errors.New("--version (-v) must be in the format " +
-					"'x.x.x', where x is a number")
-				util.HandleCmdErr(cmd, err)
-				os.Exit(1)
-			}
-
 			cmdCtx.CommandName = cmd.Name()
 			err := modules.RunCmd(&cmdCtx, cmd.CommandPath(), &modulesInfo,
 				internalReplicasetDowngradeModule, args)
 			util.HandleCmdErr(cmd, err)
 		},
-		Args: cobra.ExactArgs(1),
+		Args: cobra.MatchAll(cobra.ExactArgs(2), validateVersion(1)),
 	}
 
 	cmd.Flags().StringArrayVarP(&chosenReplicasetAliases, "replicaset", "r",
@@ -125,9 +123,6 @@ func newDowngradeCmd() *cobra.Command {
 	cmd.Flags().IntVarP(&lsnTimeout, "timeout", "t", 5,
 		"timeout for waiting the LSN synchronization (in seconds)")
 
-	cmd.Flags().StringVarP(&downgradeVersion, "version", "v", "",
-		"version to downgrade the schema to")
-
 	addOrchestratorFlags(cmd)
 	addTarantoolConnectFlags(cmd)
 	return cmd
@@ -608,8 +603,11 @@ func internalReplicasetUpgradeModule(cmdCtx *cmdcontext.CmdCtx, args []string) e
 
 // internalReplicasetDowngradeModule is a "upgrade" command for the replicaset module.
 func internalReplicasetDowngradeModule(cmdCtx *cmdcontext.CmdCtx, args []string) error {
+	target := args[0]
+	downgradeVersion := args[1]
+
 	var ctx replicasetCtx
-	if err := replicasetFillCtx(cmdCtx, &ctx, args[0], false); err != nil {
+	if err := replicasetFillCtx(cmdCtx, &ctx, target, false); err != nil {
 		return err
 	}
 	if ctx.IsInstanceConnect {
@@ -625,7 +623,7 @@ func internalReplicasetDowngradeModule(cmdCtx *cmdcontext.CmdCtx, args []string)
 		SslCiphers:  replicasetSslCiphers,
 	}
 	var connOpts connector.ConnectOpts
-	connOpts, _ = resolveConnectOpts(cmdCtx, cliOpts, &connectCtx, args[0])
+	connOpts, _ = resolveConnectOpts(cmdCtx, cliOpts, &connectCtx, target)
 
 	return replicasetcmd.Downgrade(replicasetcmd.DiscoveryCtx{
 		IsApplication: ctx.IsApplication,

test/integration/replicaset/test_replicaset_downgrade.py

@@ -62,7 +62,7 @@ def test_downgrade_multi_master(tt_cmd, tmpdir_with_cfg):
             )
             assert file != ""
 
-        downgrade_cmd = [tt_cmd, "replicaset", "downgrade", app_name, "-v=3.0.0"]
+        downgrade_cmd = [tt_cmd, "replicaset", "downgrade", app_name, "3.0.0"]
 
         rc, out = run_command_and_get_output(downgrade_cmd, cwd=tmpdir)
         assert rc == 1
@@ -97,7 +97,7 @@ def test_downgrade_t2_app_dummy_replicaset(tt_cmd):
             assert file != ""
 
             downgrade_cmd = [
-                tt_cmd, "replicaset", "downgrade", app_name, "--custom", "-v=2.8.2"
+                tt_cmd, "replicaset", "downgrade", app_name, "2.8.2", "--custom"
             ]
             rc, out = run_command_and_get_output(downgrade_cmd, cwd=test_app_path)
             assert rc == 0
@@ -139,7 +139,7 @@ def test_cluster_replicasets(tt_cmd, tmp_path):
                 cmd_master
             )
 
-        downgrade_cmd = [tt_cmd, "replicaset", "downgrade", app_name, "-t=15", "-v=2.11.1"]
+        downgrade_cmd = [tt_cmd, "replicaset", "downgrade", app_name, "2.11.1", "-t=15"]
         rc, out = run_command_and_get_output(downgrade_cmd, cwd=tmp_path)
 
         assert rc == 0
@@ -171,13 +171,13 @@ def test_downgrade_invalid_version(tt_cmd, tmp_path):
         app.build()
         app.start()
 
-        downgrade_cmd = [tt_cmd, "replicaset", "downgrade", app_name, "-t=15", "-v=1.1.1"]
+        downgrade_cmd = [tt_cmd, "replicaset", "downgrade", app_name, "1.1.1", "-t=15"]
         rc, out = run_command_and_get_output(downgrade_cmd, cwd=tmp_path)
 
         assert rc == 1
         assert "Version '1.1.1' is not allowed." in out
 
-        downgrade_cmd = [tt_cmd, "replicaset", "downgrade", app_name, "-t=15", "-v=3.0"]
+        downgrade_cmd = [tt_cmd, "replicaset", "downgrade", app_name, "3.0", "-t=15"]
         rc, out = run_command_and_get_output(downgrade_cmd, cwd=tmp_path)
 
         assert "--version (-v) must be in the format 'x.x.x', where x is a number" in out
@@ -215,7 +215,7 @@ def test_downgrade_remote_replicasets(tt_cmd, tmpdir_with_cfg):
         )
 
         uri = "tcp://client:[email protected]:3301"
-        upgrade_cmd = [tt_cmd, "replicaset", "downgrade", uri, "-t=15", "-v=2.11.1"]
+        upgrade_cmd = [tt_cmd, "replicaset", "downgrade", uri, "2.11.1", "-t=15"]
         rc, out = run_command_and_get_output(upgrade_cmd, cwd=tmpdir)
         assert rc == 0
         assert "ok" in out
@@ -267,7 +267,7 @@ def have_buckets_created():
     assert wait_event(10, have_buckets_created)
 
     app_dir = cartridge_app.workdir
-    upgrade_cmd = [tt_cmd, "replicaset", "downgrade", cartridge_name, "-t=15", "-v=2.10.0"]
+    upgrade_cmd = [tt_cmd, "replicaset", "downgrade", cartridge_name, "2.10.0", "-t=15"]
     rc, out = run_command_and_get_output(upgrade_cmd, cwd=app_dir)
     assert rc == 0
     assert "ok" in out