REFACTOR: Enhance password validation

CLAUDE.md

@@ -38,7 +38,9 @@ cmd/                 cobra 커맨드 정의 — 얇게 유지. 인자 파싱과
 internal/            모든 실제 로직. cmd/에서 로직을 구현하지 않는다.
   config.go          viper 설정 로드 (Flags, Config 전역)
   const.go           ZooKeeper znode 경로 상수
-  util.go            ZK 커넥션/znode 헬퍼, 표준입력 읽기
+  zookeeper.go       ZooKeeper 커넥션/znode 헬퍼
+  prompt.go          표준입력 및 확인 프롬프트
+  password.go        ACL 비밀번호 정책 검증
   topology/          YAML 토폴로지 타입 + Validate() + Load*()
   store/             ~/.arcusctl 하위 배포 메타데이터 영속화
   ssh/               ssh/scp 서브프로세스 실행 래퍼
@@ -86,7 +88,7 @@ internal/            모든 실제 로직. cmd/에서 로직을 구현하지 않
 - 사용자에게 보이는 에러 메시지는 **무엇이 / 왜 실패했고 / 어떻게 복구하는지**를 담는다. 원격 호스트가 관련되면 어느 호스트인지 반드시 포함한다.
 - **cobra 커맨드는 `RunE`로 error를 반환한다.** `cmd.Execute()`가 stderr 출력과 exit code 1을 담당한다. 커맨드 안에서
   `panic()`이나 `os.Exit()`을 부르지 않는다.
-  > 현재 `cmd/` 일부와 `internal/config.go`, `internal/util.go`에 `panic(err)`이
+  > 현재 `cmd/` 일부와 `internal/config.go`에 `panic(err)`이
   > 남아 있다. 이것은 **정리 대상인 과거 패턴**이며 새 코드가 따라갈 기준이 아니다.
   > 건드리는 김에 점진적으로 `RunE` + error 반환으로 옮긴다.
 

cmd/acl/admin/passwd.go

@@ -22,34 +22,48 @@ For password requirements, see: https://github.com/jam2in/arcusctl/blob/main/doc
 	Example: `  # Change admin password for group 'cache01'
   arcusctl acl admin passwd cache01`,
 	Args: cobra.ExactArgs(1),
-	Run: func(cmd *cobra.Command, args []string) {
+	RunE: func(cmd *cobra.Command, args []string) error {
 		groupName := args[0]
 
-		adminName := internal.ReadStdin("admin name", false)
-		adminPassword := internal.ReadStdin("admin password", true)
-		newPassword := internal.ReadStdin("new password", true)
-		if newPassword != internal.ReadStdin("repeat new password", true) {
-			panic("password does not match")
+		adminName, err := internal.ReadInput("admin name")
+		if err != nil {
+			return fmt.Errorf("read admin name: %w", err)
+		}
+		adminPassword, err := internal.ReadPassword("admin password")
+		if err != nil {
+			return err
+		}
+		newPassword, err := internal.ReadPassword("new password")
+		if err != nil {
+			return err
+		}
+		repeatedPassword, err := internal.ReadPassword("repeat new password")
+		if err != nil {
+			return err
+		}
+		if newPassword != repeatedPassword {
+			return errors.New("password does not match")
 		}
 
 		conn, err := internal.ConnectZooKeeper(internal.Config.ZooKeeper)
 		if err != nil {
-			panic(err)
+			return err
 		}
 		defer conn.Close()
 
 		if err := conn.AddAuth("digest", []byte(adminName+":"+adminPassword)); err != nil {
-			panic(err)
+			return fmt.Errorf("authenticate ZooKeeper admin %q: %w", adminName, err)
 		}
 
 		acls := append(zk.DigestACL(zk.PermAll, adminName, newPassword),
 			zk.WorldACL(zk.PermRead)...)
 
 		if err := setAclRecursive(conn, internal.ZPATH_ACL_ROOT+"/"+groupName, acls); err != nil {
-			panic(err)
+			return err
 		}
 
 		fmt.Println("OK")
+		return nil
 	},
 }
 

cmd/acl/group/add.go

@@ -1,6 +1,7 @@
 package group
 
 import (
+	"errors"
 	"fmt"
 
 	"github.com/go-zookeeper/zk"
@@ -21,32 +22,45 @@ For password requirements, see: https://github.com/jam2in/arcusctl/blob/main/doc
 	Example: `  # Create a new group named 'cache01'
   arcusctl acl group add cache01`,
 	Args: cobra.ExactArgs(1),
-	Run: func(cmd *cobra.Command, args []string) {
+	RunE: func(cmd *cobra.Command, args []string) error {
 		groupName := args[0]
 
-		adminName := internal.ReadStdin("admin name", false)
-		adminPassword := internal.ReadStdin("password", true)
-		if adminPassword != internal.ReadStdin("repeat password", true) {
-			panic("password does not match")
+		adminName, err := internal.ReadInput("admin name")
+		if err != nil {
+			return fmt.Errorf("read admin name: %w", err)
+		}
+		adminPassword, err := internal.ReadPassword("password")
+		if err != nil {
+			return err
+		}
+		repeatedPassword, err := internal.ReadPassword("repeat password")
+		if err != nil {
+			return err
+		}
+		if adminPassword != repeatedPassword {
+			return errors.New("password does not match")
 		}
 
 		conn, err := internal.ConnectZooKeeper(internal.Config.ZooKeeper)
 		if err != nil {
-			panic(err)
+			return err
 		}
 		defer conn.Close()
 
 		if err := conn.AddAuth("digest", []byte(adminName+":"+adminPassword)); err != nil {
-			panic(err)
+			return fmt.Errorf("authenticate ZooKeeper admin %q: %w", adminName, err)
 		}
 
-		internal.EnsureZPath(conn, internal.ZPATH_ACL_ROOT)
+		if err := internal.EnsureZNode(conn, internal.ZPATH_ACL_ROOT); err != nil {
+			return err
+		}
 		if _, err := conn.Create(internal.ZPATH_ACL_ROOT+"/"+groupName, nil, 0,
 			append(zk.DigestACL(zk.PermAll, adminName, adminPassword),
 				zk.WorldACL(zk.PermRead)...)); err != nil {
-			panic(err)
+			return fmt.Errorf("create ACL group %q: %w", groupName, err)
 		}
 
 		fmt.Println("OK")
+		return nil
 	},
 }

cmd/acl/user/add.go

@@ -1,6 +1,7 @@
 package user
 
 import (
+	"errors"
 	"fmt"
 	"strings"
 
@@ -25,35 +26,37 @@ For password requirements, see: https://github.com/jam2in/arcusctl/blob/main/doc
   # Add a user 'john' for operator with logging enabled
   arcusctl acl user add cache01 john attr,scan,flush,admin logAll`,
 	Args: cobra.RangeArgs(3, 4),
-	Run: func(cmd *cobra.Command, args []string) {
+	RunE: func(cmd *cobra.Command, args []string) error {
 		groupName := args[0]
 		userName := args[1]
 		permissions := args[2]
 		if len(args) == 4 {
 			if args[3] == "logAll" {
 				permissions += ",logall"
 			} else {
-				panic("invalid arguments")
+				return fmt.Errorf("invalid fourth argument %q: expected logAll", args[3])
 			}
 		}
 
-		adminName := internal.ReadStdin("admin name", false)
-		adminPassword := internal.ReadStdin("admin password", true)
-		userPassword := internal.ReadStdin("user password", true)
-		if userPassword != internal.ReadStdin("repeat user password", true) {
-			panic("password does not match")
+		adminName, adminPassword, err := readAdminCredentials()
+		if err != nil {
+			return err
+		}
+		userPassword, err := readConfirmedPassword("user password", "repeat user password")
+		if err != nil {
+			return err
 		}
 
 		secret := scram.GenerateScramSHA256Secret(userPassword, nil, 0)
 
 		conn, err := internal.ConnectZooKeeper(internal.Config.ZooKeeper)
 		if err != nil {
-			panic(err)
+			return err
 		}
 		defer conn.Close()
 
 		if err := conn.AddAuth("digest", []byte(adminName+":"+adminPassword)); err != nil {
-			panic(err)
+			return fmt.Errorf("authenticate ZooKeeper admin %q: %w", adminName, err)
 		}
 
 		acls := append(zk.DigestACL(zk.PermAll, adminName, adminPassword),
@@ -73,10 +76,11 @@ For password requirements, see: https://github.com/jam2in/arcusctl/blob/main/doc
 				Flags: 0,
 			},
 		); err != nil {
-			panic(err)
+			return fmt.Errorf("create ACL user %q in group %q: %w", userName, groupName, err)
 		}
 
 		fmt.Println("OK")
+		return nil
 	},
 }
 
@@ -89,35 +93,38 @@ For password requirements, see: https://github.com/jam2in/arcusctl/blob/main/doc
 	Example: `  # Change password for user 'john' in group 'cache01'
   arcusctl acl user passwd cache01 john`,
 	Args: cobra.ExactArgs(2),
-	Run: func(cmd *cobra.Command, args []string) {
+	RunE: func(cmd *cobra.Command, args []string) error {
 		groupName := args[0]
 		userName := args[1]
 
-		adminName := internal.ReadStdin("admin name", false)
-		adminPassword := internal.ReadStdin("admin password", true)
-		userPassword := internal.ReadStdin("user password", true)
-		if userPassword != internal.ReadStdin("repeat user password", true) {
-			panic("password does not match")
+		adminName, adminPassword, err := readAdminCredentials()
+		if err != nil {
+			return err
+		}
+		userPassword, err := readConfirmedPassword("user password", "repeat user password")
+		if err != nil {
+			return err
 		}
 
 		secret := scram.GenerateScramSHA256Secret(userPassword, nil, 0)
 
 		conn, err := internal.ConnectZooKeeper(internal.Config.ZooKeeper)
 		if err != nil {
-			panic(err)
+			return err
 		}
 		defer conn.Close()
 
 		if err := conn.AddAuth("digest", []byte(adminName+":"+adminPassword)); err != nil {
-			panic(err)
+			return fmt.Errorf("authenticate ZooKeeper admin %q: %w", adminName, err)
 		}
 
 		if _, err := conn.Set(internal.ZPATH_ACL_ROOT+"/"+groupName+"/"+userName+"/"+propName,
 			[]byte(secret.EncodeToBase64()), -1); err != nil {
-			panic(err)
+			return fmt.Errorf("change password for ACL user %q in group %q: %w", userName, groupName, err)
 		}
 
 		fmt.Println("OK")
+		return nil
 	},
 }
 
@@ -131,28 +138,30 @@ The logAll flag will be preserved from the user's existing configuration.`,
 	Example: `  # Update user permissions to key-value only
   arcusctl acl user permissions cache01 john kv`,
 	Args: cobra.ExactArgs(3),
-	Run: func(cmd *cobra.Command, args []string) {
+	RunE: func(cmd *cobra.Command, args []string) error {
 		groupName := args[0]
 		userName := args[1]
 		permissions := args[2]
 
-		adminName := internal.ReadStdin("admin name", false)
-		adminPassword := internal.ReadStdin("admin password", true)
+		adminName, adminPassword, err := readAdminCredentials()
+		if err != nil {
+			return err
+		}
 
 		conn, err := internal.ConnectZooKeeper(internal.Config.ZooKeeper)
 		if err != nil {
-			panic(err)
+			return err
 		}
 		defer conn.Close()
 
 		if err := conn.AddAuth("digest", []byte(adminName+":"+adminPassword)); err != nil {
-			panic(err)
+			return fmt.Errorf("authenticate ZooKeeper admin %q: %w", adminName, err)
 		}
 
-		// It's pretty stupid
+		// Preserve the existing logall flag while replacing the other permissions.
 		beforePerm, _, err := conn.Get(internal.ZPATH_ACL_ROOT + "/" + groupName + "/" + userName)
 		if err != nil {
-			panic(err)
+			return fmt.Errorf("read permissions for ACL user %q in group %q: %w", userName, groupName, err)
 		}
 		beforePermList := strings.Split(string(beforePerm), ",")
 		if beforePermList[len(beforePermList)-1] == "logall" {
@@ -161,9 +170,40 @@ The logAll flag will be preserved from the user's existing configuration.`,
 
 		if _, err := conn.Set(internal.ZPATH_ACL_ROOT+"/"+groupName+"/"+userName,
 			[]byte(permissions), -1); err != nil {
-			panic(err)
+			return fmt.Errorf("update permissions for ACL user %q in group %q: %w", userName, groupName, err)
 		}
 
 		fmt.Println("OK")
+		return nil
 	},
 }
+
+func readAdminCredentials() (string, string, error) {
+	name, err := internal.ReadInput("admin name")
+	if err != nil {
+		return "", "", fmt.Errorf("read admin name: %w", err)
+	}
+
+	password, err := internal.ReadPassword("admin password")
+	if err != nil {
+		return "", "", err
+	}
+
+	return name, password, nil
+}
+
+func readConfirmedPassword(prompt string, repeatPrompt string) (string, error) {
+	password, err := internal.ReadPassword(prompt)
+	if err != nil {
+		return "", err
+	}
+	repeatedPassword, err := internal.ReadPassword(repeatPrompt)
+	if err != nil {
+		return "", err
+	}
+	if password != repeatedPassword {
+		return "", errors.New("password does not match")
+	}
+
+	return password, nil
+}

cmd/acl/user/remove.go

@@ -20,25 +20,27 @@ and will fail if active connections are found.`,
 	Example: `  # Remove user 'john' from group 'cache01'
   arcusctl acl user remove cache01 john`,
 	Args: cobra.ExactArgs(2),
-	Run: func(cmd *cobra.Command, args []string) {
+	RunE: func(cmd *cobra.Command, args []string) error {
 		groupName := args[0]
 		userName := args[1]
 
-		adminName := internal.ReadStdin("admin name", false)
-		adminPassword := internal.ReadStdin("admin password", true)
+		adminName, adminPassword, err := readAdminCredentials()
+		if err != nil {
+			return err
+		}
 
 		conn, err := internal.ConnectZooKeeper(internal.Config.ZooKeeper)
 		if err != nil {
-			panic(err)
+			return err
 		}
 		defer conn.Close()
 
 		if err := conn.AddAuth("digest", []byte(adminName+":"+adminPassword)); err != nil {
-			panic(err)
+			return fmt.Errorf("authenticate ZooKeeper admin %q: %w", adminName, err)
 		}
 
 		if err := CheckClientList(conn, groupName, userName); err != nil {
-			panic(err)
+			return err
 		}
 
 		if _, err := conn.Multi(
@@ -51,10 +53,11 @@ and will fail if active connections are found.`,
 				Version: -1,
 			},
 		); err != nil {
-			panic(err)
+			return fmt.Errorf("remove ACL user %q from group %q: %w", userName, groupName, err)
 		}
 
 		fmt.Println("OK")
+		return nil
 	},
 }
 

internal/cluster/delete.go

@@ -22,7 +22,11 @@ func Delete(serviceCode string, purge bool) error {
 	}
 
 	fmt.Printf("This will remove Arcus cluster %q from all servers.\n", serviceCode)
-	if !internal.Confirm("Are you sure you want to proceed? (y/N): ") {
+	confirmed, err := internal.Confirm("Are you sure you want to proceed? (y/N): ")
+	if err != nil {
+		return fmt.Errorf("confirm Arcus cluster deletion: %w", err)
+	}
+	if !confirmed {
 		fmt.Println("Aborted.")
 		return nil
 	}