tcm: add tt tcm stop command

@TarantoolBot document
Title: add the tt tcm stop command.

Add command tt tcm stop to gracefully terminate TCM:
- Works in both modes(watchdog and interactive)
- Stops all subprocesses

Closes #TNTP-1993

Author: AlexandrLitkevich

CHANGELOG.md

@@ -13,18 +13,16 @@ import (
 	"github.com/jedib0t/go-pretty/v6/text"
 	"github.com/spf13/cobra"
 	"github.com/tarantool/tt/cli/cmdcontext"
-	"github.com/tarantool/tt/cli/modules"
 	"github.com/tarantool/tt/cli/process_utils"
 	tcmCmd "github.com/tarantool/tt/cli/tcm"
-	"github.com/tarantool/tt/cli/util"
 	libwatchdog "github.com/tarantool/tt/lib/watchdog"
 )
 
 var tcmCtx = tcmCmd.TcmCtx{}
 
 const (
-	tcmPidFile      = "tcmPidFile.pid"
-	watchdogPidFile = "watchdogPidFile.pid"
+	tcmPidFile      = "tcm.pid"
+	watchdogPidFile = "watchdog.pid"
 )
 
 func newTcmStartCmd() *cobra.Command {
@@ -34,11 +32,7 @@ func newTcmStartCmd() *cobra.Command {
 		Long: `Start to the tcm.
 		tt tcm start --watchdog
 		tt tcm start --path`,
-		Run: func(cmd *cobra.Command, args []string) {
-			cmdCtx.CommandName = cmd.Name()
-			err := modules.RunCmd(&cmdCtx, cmd.CommandPath(), &modulesInfo, internalStartTcm, args)
-			util.HandleCmdErr(cmd, err)
-		},
+		Run: RunModuleFunc(internalStartTcm),
 	}
 	tcmCmd.Flags().StringVar(&tcmCtx.Executable, "path", "", "the path to the tcm binary file")
 	tcmCmd.Flags().BoolVar(&tcmCtx.Watchdog, "watchdog", false, "enables the watchdog")
@@ -52,11 +46,7 @@ func newTcmStatusCmd() *cobra.Command {
 		Short: "Status tcm application",
 		Long: `Status to the tcm.
 		tt tcm status`,
-		Run: func(cmd *cobra.Command, args []string) {
-			cmdCtx.CommandName = cmd.Name()
-			err := modules.RunCmd(&cmdCtx, cmd.CommandPath(), &modulesInfo, internalTcmStatus, args)
-			util.HandleCmdErr(cmd, err)
-		},
+		Run: RunModuleFunc(internalTcmStatus),
 	}
 	return tcmCmd
 }
@@ -66,11 +56,7 @@ func newTcmStopCmd() *cobra.Command {
 		Use:   "stop",
 		Short: "Stop tcm application",
 		Long:  `Stop to the tcm. tt tcm stop`,
-		Run: func(cmd *cobra.Command, args []string) {
-			cmdCtx.CommandName = cmd.Name()
-			err := modules.RunCmd(&cmdCtx, cmd.CommandPath(), &modulesInfo, internalTcmStop, args)
-			util.HandleCmdErr(cmd, err)
-		},
+		Run:   RunModuleFunc(internalTcmStop),
 	}
 	return tcmCmd
 }
@@ -178,13 +164,13 @@ func internalTcmStop(cmdCtx *cmdcontext.CmdCtx, args []string) error {
 		if err != nil {
 			return err
 		}
-		log.Println("Watchdog and TCM stoped")
+		log.Println("Watchdog and TCM stopped")
 	} else {
 		_, err := process_utils.StopProcess(tcmPidFile)
 		if err != nil {
 			return err
 		}
-		log.Println("TCM stoped")
+		log.Println("TCM stopped")
 	}
 
 	return nil

cli/cmd/tcm.go

@@ -112,14 +112,14 @@ func ExistsAndRecord(pidFileName string) (bool, error) {
 		// The PID file already exists. We have to check if the process is alive.
 		pid, err := GetPIDFromFile(pidFileName)
 		if err != nil {
-			return false, fmt.Errorf(`pID file exists, but PID can't be read. Error: "%v"`, err)
+			return false, fmt.Errorf(`PID file exists, but PID can't be read. Error: "%v"`, err)
 		}
 		if res, _ := IsProcessAlive(pid); res {
 			return true, nil
 		}
 	} else if !os.IsNotExist(err) {
-		return false, fmt.Errorf(`something went wrong while trying to read the PID file. Error: "%v"`,
-			err)
+		return false, fmt.Errorf(`something went wrong while trying to read the`+
+			`PID file. Error: "%v"`, err)
 	}
 
 	return false, nil

cli/process_utils/process_utils.go

@@ -0,0 +1,36 @@
+package process_utils
+
+import (
+	"os"
+	"os/exec"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func Test_ExistsAndRecord(t *testing.T) {
+	testFile := "test.pid"
+	invalid := "invalid.pid"
+	cmd := exec.Command("sleep", "10")
+
+	t.Cleanup(func() {
+		os.Remove(testFile)
+	})
+
+	err := cmd.Start()
+	require.NoError(t, err)
+
+	err = CreatePIDFile(testFile, cmd.Process.Pid)
+	require.NoError(t, err)
+
+	status, err := ExistsAndRecord(testFile)
+	require.NoError(t, err)
+	require.True(t, status)
+
+	err = cmd.Process.Kill()
+	require.NoError(t, err)
+
+	statusInvalid, err := ExistsAndRecord(invalid)
+	require.False(t, statusInvalid)
+	require.NoError(t, err)
+}

cli/process_utils/process_utils_test.go

@@ -1,9 +1,13 @@
 package tcm
 
+// TcmCtx holds parameters and state for managing the TCM process and its watchdog.
 type TcmCtx struct {
+	// Path to the TCM executable file.
 	Executable string
+	// Path to the file storing the TCM process PID.
 	TcmPidFile string
-
-	Watchdog       bool
+	// Flag indicating whether the watchdog is enabled.
+	Watchdog bool
+	// Path to the file storing the watchdog process PID.
 	WathdogPidFile string
 }