Implement getUserInfo function to read environment variables (#24)

* move env calls out of packages

* userinfo

* Implement getUserInfo function to read environment variables

Implemented the getUserInfo function in cli/cli.go to read environment
variables and populate the UserInfo struct with appropriate user
information for both sudo and non-sudo scenarios.

Features:
- Detects sudo usage via SUDO_USER environment variable
- Retrieves original user information when running under sudo
- Parses SUDO_UID and SUDO_GID for proper user credentials
- Handles XDG_CONFIG_HOME for config directory determination
- Fallback to current user when not running under sudo
- Comprehensive error handling with graceful fallbacks

Cleanup:
- Removed all commented environment variable code from:
  - namespace/linux.go (sudo user/uid/gid handling)
  - namespace/macos.go (sudo user/uid handling)
  - tls/tls.go (commented getConfigDir function)
- Centralized all environment variable reading in CLI package

All tests pass and code compiles successfully.

Co-authored-by: f0ssel <[email protected]>

* move code

---------

Co-authored-by: blink-so[bot] <211532188+blink-so[bot]@users.noreply.github.com>
Co-authored-by: f0ssel <[email protected]>

Author: f0ssel

cli/cli.go

@@ -6,11 +6,15 @@ import (
 	"log/slog"
 	"os"
 	"os/signal"
+	"os/user"
+	"path/filepath"
+	"strconv"
 	"strings"
 	"syscall"
 
 	"github.com/coder/jail"
 	"github.com/coder/jail/audit"
+	"github.com/coder/jail/namespace"
 	"github.com/coder/jail/rules"
 	"github.com/coder/jail/tls"
 	"github.com/coder/serpent"
@@ -64,35 +68,12 @@ Examples:
 	}
 }
 
-// setupLogging creates a slog logger with the specified level
-func setupLogging(logLevel string) *slog.Logger {
-	var level slog.Level
-	switch strings.ToLower(logLevel) {
-	case "error":
-		level = slog.LevelError
-	case "warn":
-		level = slog.LevelWarn
-	case "info":
-		level = slog.LevelInfo
-	case "debug":
-		level = slog.LevelDebug
-	default:
-		level = slog.LevelWarn // Default to warn if invalid level
-	}
-
-	// Create a standard slog logger with the appropriate level
-	handler := slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{
-		Level: level,
-	})
-
-	return slog.New(handler)
-}
-
 // Run executes the jail command with the given configuration and arguments
 func Run(ctx context.Context, config Config, args []string) error {
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 	logger := setupLogging(config.LogLevel)
+	userInfo := getUserInfo()
 
 	// Get command arguments
 	if len(args) == 0 {
@@ -118,7 +99,10 @@ func Run(ctx context.Context, config Config, args []string) error {
 	auditor := audit.NewLoggingAuditor(logger)
 
 	// Create certificate manager
-	certManager, err := tls.NewCertificateManager(logger)
+	certManager, err := tls.NewCertificateManager(tls.Config{
+		Logger:    logger,
+		ConfigDir: userInfo.ConfigDir,
+	})
 	if err != nil {
 		logger.Error("Failed to create certificate manager", "error", err)
 		return fmt.Errorf("failed to create certificate manager: %v", err)
@@ -173,3 +157,101 @@ func Run(ctx context.Context, config Config, args []string) error {
 
 	return nil
 }
+
+func getUserInfo() namespace.UserInfo {
+	// get the user info of the original user even if we are running under sudo
+	sudoUser := os.Getenv("SUDO_USER")
+
+	// If running under sudo, get original user information
+	if sudoUser != "" {
+		user, err := user.Lookup(sudoUser)
+		if err != nil {
+			// Fallback to current user if lookup fails
+			return getCurrentUserInfo()
+		}
+
+		// Parse SUDO_UID and SUDO_GID
+		uid := 0
+		gid := 0
+
+		if sudoUID := os.Getenv("SUDO_UID"); sudoUID != "" {
+			if parsedUID, err := strconv.Atoi(sudoUID); err == nil {
+				uid = parsedUID
+			}
+		}
+
+		if sudoGID := os.Getenv("SUDO_GID"); sudoGID != "" {
+			if parsedGID, err := strconv.Atoi(sudoGID); err == nil {
+				gid = parsedGID
+			}
+		}
+
+		configDir := getConfigDir(user.HomeDir)
+
+		return namespace.UserInfo{
+			Username:  sudoUser,
+			Uid:       uid,
+			Gid:       gid,
+			HomeDir:   user.HomeDir,
+			ConfigDir: configDir,
+		}
+	}
+
+	// Not running under sudo, use current user
+	return getCurrentUserInfo()
+}
+
+// setupLogging creates a slog logger with the specified level
+func setupLogging(logLevel string) *slog.Logger {
+	var level slog.Level
+	switch strings.ToLower(logLevel) {
+	case "error":
+		level = slog.LevelError
+	case "warn":
+		level = slog.LevelWarn
+	case "info":
+		level = slog.LevelInfo
+	case "debug":
+		level = slog.LevelDebug
+	default:
+		level = slog.LevelWarn // Default to warn if invalid level
+	}
+
+	// Create a standard slog logger with the appropriate level
+	handler := slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{
+		Level: level,
+	})
+
+	return slog.New(handler)
+}
+
+// getCurrentUserInfo gets information for the current user
+func getCurrentUserInfo() namespace.UserInfo {
+	currentUser, err := user.Current()
+	if err != nil {
+		// Fallback with empty values if we can't get user info
+		return namespace.UserInfo{}
+	}
+
+	uid, _ := strconv.Atoi(currentUser.Uid)
+	gid, _ := strconv.Atoi(currentUser.Gid)
+
+	configDir := getConfigDir(currentUser.HomeDir)
+
+	return namespace.UserInfo{
+		Username:  currentUser.Username,
+		Uid:       uid,
+		Gid:       gid,
+		HomeDir:   currentUser.HomeDir,
+		ConfigDir: configDir,
+	}
+}
+
+// getConfigDir determines the config directory based on XDG_CONFIG_HOME or fallback
+func getConfigDir(homeDir string) string {
+	// Use XDG_CONFIG_HOME if set, otherwise fallback to ~/.config/coder_jail
+	if xdgConfigHome := os.Getenv("XDG_CONFIG_HOME"); xdgConfigHome != "" {
+		return filepath.Join(xdgConfigHome, "coder_jail")
+	}
+	return filepath.Join(homeDir, ".config", "coder_jail")
+}

jail

@@ -7,8 +7,6 @@ import (
 	"log/slog"
 	"os"
 	"os/exec"
-	"os/user"
-	"strconv"
 	"strings"
 	"syscall"
 	"time"
@@ -23,6 +21,10 @@ type Linux struct {
 	procAttr       *syscall.SysProcAttr
 	httpProxyPort  int
 	httpsProxyPort int
+	user           string
+	homeDir        string
+	uid            int
+	gid            int
 }
 
 // NewLinux creates a new Linux network jail instance
@@ -84,42 +86,17 @@ func (l *Linux) Start() error {
 		}
 	}
 
-	// When running under sudo, restore essential user environment variables
-	sudoUser := os.Getenv("SUDO_USER")
-	if sudoUser != "" {
-		user, err := user.Lookup(sudoUser)
-		if err == nil {
-			// Set HOME to original user's home directory
-			l.preparedEnv["HOME"] = user.HomeDir
-			// Set USER to original username
-			l.preparedEnv["USER"] = sudoUser
-			// Set LOGNAME to original username (some tools check this instead of USER)
-			l.preparedEnv["LOGNAME"] = sudoUser
-			l.logger.Debug("Restored user environment", "home", user.HomeDir, "user", sudoUser)
-		}
-	}
+	// Set HOME to original user's home directory
+	l.preparedEnv["HOME"] = l.homeDir
+	// Set USER to original username
+	l.preparedEnv["USER"] = l.user
+	// Set LOGNAME to original username (some tools check this instead of USER)
+	l.preparedEnv["LOGNAME"] = l.user
 
-	// Prepare process credentials once during setup
-	l.logger.Debug("Preparing process credentials")
-	var gid, uid int
-	sudoUID := os.Getenv("SUDO_UID")
-	if sudoUID != "" {
-		uid, err = strconv.Atoi(sudoUID)
-		if err != nil {
-			l.logger.Warn("Invalid SUDO_UID, subprocess will run as root", "sudo_uid", sudoUID, "error", err)
-		}
-	}
-	sudoGID := os.Getenv("SUDO_GID")
-	if sudoGID != "" {
-		gid, err = strconv.Atoi(sudoGID)
-		if err != nil {
-			l.logger.Warn("Invalid SUDO_GID, subprocess will run as root", "sudo_gid", sudoGID, "error", err)
-		}
-	}
 	l.procAttr = &syscall.SysProcAttr{
 		Credential: &syscall.Credential{
-			Uid: uint32(uid),
-			Gid: uint32(gid),
+			Uid: uint32(l.uid),
+			Gid: uint32(l.gid),
 		},
 	}
 
@@ -303,4 +280,4 @@ func (l *Linux) removeNamespace() error {
 		return fmt.Errorf("failed to remove namespace: %v", err)
 	}
 	return nil
-}
+}

namespace/linux.go

@@ -7,7 +7,6 @@ import (
 	"log/slog"
 	"os"
 	"os/exec"
-	"os/user"
 	"strconv"
 	"strings"
 	"syscall"
@@ -20,14 +19,15 @@ const (
 
 // MacOSNetJail implements network jail using macOS PF (Packet Filter) and group-based isolation
 type MacOSNetJail struct {
-	groupID        int
+	restrictedGid  int
 	pfRulesPath    string
 	mainRulesPath  string
 	logger         *slog.Logger
 	preparedEnv    map[string]string
 	procAttr       *syscall.SysProcAttr
 	httpProxyPort  int
 	httpsProxyPort int
+	userInfo       UserInfo
 }
 
 // NewMacOS creates a new macOS network jail instance
@@ -49,6 +49,7 @@ func NewMacOS(config Config) (*MacOSNetJail, error) {
 		preparedEnv:    preparedEnv,
 		httpProxyPort:  config.HttpProxyPort,
 		httpsProxyPort: config.HttpsProxyPort,
+		userInfo:       config.UserInfo,
 	}, nil
 }
 
@@ -83,47 +84,23 @@ func (m *MacOSNetJail) Start() error {
 		}
 	}
 
-	// When running under sudo, restore essential user environment variables
-	sudoUser := os.Getenv("SUDO_USER")
-	if sudoUser != "" {
-		user, err := user.Lookup(sudoUser)
-		if err == nil {
-			// Set HOME to original user's home directory
-			m.preparedEnv["HOME"] = user.HomeDir
-			// Set USER to original username
-			m.preparedEnv["USER"] = sudoUser
-			// Set LOGNAME to original username (some tools check this instead of USER)
-			m.preparedEnv["LOGNAME"] = sudoUser
-			m.logger.Debug("Restored user environment", "home", user.HomeDir, "user", sudoUser)
-		}
-	}
+	// Set HOME to original user's home directory
+	m.preparedEnv["HOME"] = m.userInfo.HomeDir
+	// Set USER to original username
+	m.preparedEnv["USER"] = m.userInfo.Username
+	// Set LOGNAME to original username (some tools check this instead of USER)
+	m.preparedEnv["LOGNAME"] = m.userInfo.Username
 
 	// Prepare process credentials once during setup
 	m.logger.Debug("Preparing process credentials")
+	// Use original user ID but KEEP the jail group for network isolation
 	procAttr := &syscall.SysProcAttr{
 		Credential: &syscall.Credential{
-			Gid: uint32(m.groupID),
+			Uid: uint32(m.userInfo.Uid),
+			Gid: uint32(m.restrictedGid),
 		},
 	}
 
-	// Drop privileges to original user if running under sudo
-	sudoUID := os.Getenv("SUDO_UID")
-	if sudoUID != "" {
-		uid, err := strconv.Atoi(sudoUID)
-		if err != nil {
-			m.logger.Warn("Invalid SUDO_UID, subprocess will run as root", "sudo_uid", sudoUID, "error", err)
-		} else {
-			// Use original user ID but KEEP the jail group for network isolation
-			procAttr = &syscall.SysProcAttr{
-				Credential: &syscall.Credential{
-					Uid: uint32(uid),
-					Gid: uint32(m.groupID), // Keep jail group, not original user's group
-				},
-			}
-			m.logger.Debug("Dropping privileges to original user with jail group", "uid", uid, "jail_gid", m.groupID)
-		}
-	}
-
 	// Store prepared process attributes for use in Command method
 	m.procAttr = procAttr
 
@@ -136,7 +113,7 @@ func (m *MacOSNetJail) Command(command []string) *exec.Cmd {
 	m.logger.Debug("Command called", "command", command)
 
 	// Create command directly (no sg wrapper needed)
-	m.logger.Debug("Creating command with group membership", "groupID", m.groupID)
+	m.logger.Debug("Creating command with group membership", "groupID", m.restrictedGid)
 	cmd := exec.Command(command[0], command[1:]...)
 	m.logger.Debug("Full command args", "args", command)
 
@@ -190,7 +167,7 @@ func (m *MacOSNetJail) ensureGroup() error {
 					if err != nil {
 						return fmt.Errorf("failed to parse GID: %v", err)
 					}
-					m.groupID = gid
+					m.restrictedGid = gid
 					return nil
 				}
 			}
@@ -219,7 +196,7 @@ func (m *MacOSNetJail) ensureGroup() error {
 				if err != nil {
 					return fmt.Errorf("failed to parse GID: %v", err)
 				}
-				m.groupID = gid
+				m.restrictedGid = gid
 				return nil
 			}
 		}
@@ -276,15 +253,15 @@ pass out on %s route-to (lo0 127.0.0.1) inet proto tcp from any to any group %d
 # Allow all loopback traffic
 pass on lo0 all
 `,
-		m.groupID,
+		m.restrictedGid,
 		iface,
 		m.httpsProxyPort, // Use HTTPS proxy port for all TCP traffic
-		m.groupID,
+		m.restrictedGid,
 		iface,
-		m.groupID,
+		m.restrictedGid,
 	)
 
-	m.logger.Debug("Comprehensive TCP jailing enabled for macOS", "group_id", m.groupID, "proxy_port", m.httpsProxyPort)
+	m.logger.Debug("Comprehensive TCP jailing enabled for macOS", "group_id", m.restrictedGid, "proxy_port", m.httpsProxyPort)
 	return rules, nil
 }
 

namespace/macos.go

@@ -0,0 +1,14 @@
+package namespace
+
+import (
+	"fmt"
+	"time"
+)
+
+const (
+	prefix = "coder_jail"
+)
+
+func newNamespaceName() string {
+	return fmt.Sprintf("%s_%d", prefix, time.Now().UnixNano()%10000000)
+}