Files
ctrld/cmd/cli/commands_service.go
Cuong Manh Le 4792183c0d Add comprehensive documentation to CLI components and core functionality
This commit extends the documentation effort by adding detailed explanatory
comments to key CLI components and core functionality throughout the cmd/
directory. The changes focus on explaining WHY certain logic is needed,
not just WHAT the code does, improving code maintainability and helping
developers understand complex business decisions.

Key improvements:
- Main entry points: Document CLI initialization, logging setup, and cache
  configuration with reasoning for design decisions
- DNS proxy core: Explain DNS proxy constants, data structures, and core
  processing pipeline for handling DNS queries
- Service management: Document service command structure, configuration
  patterns, and platform-specific service handling
- Logging infrastructure: Explain log buffer management, level encoders,
  and log formatting decisions for different use cases
- Metrics and monitoring: Document Prometheus metrics structure, HTTP
  endpoints, and conditional metric collection for performance
- Network handling: Explain Linux-specific network interface filtering,
  virtual interface detection, and DNS configuration management
- Hostname validation: Document RFC1123 compliance and DNS naming
  standards for system compatibility
- Mobile integration: Explain HTTP retry logic, fallback mechanisms, and
  mobile platform integration patterns
- Connection management: Document connection wrapper design to prevent
  log pollution during process lifecycle

Technical details:
- Added explanatory comments to 11 additional files in cmd/cli/
- Maintained consistent documentation style and format
- Preserved all existing functionality while improving code clarity
- Enhanced understanding of complex business logic and platform-specific
  behavior

These comments help future developers understand the reasoning behind
complex decisions, making the codebase more maintainable and reducing
the risk of incorrect modifications during maintenance.
2025-10-09 17:49:21 +07:00

257 lines
8.1 KiB
Go

package cli
import (
"fmt"
"os"
"runtime"
"github.com/kardianos/service"
"github.com/spf13/cobra"
)
// filterEmptyStrings removes empty strings from a slice
// This is used to clean up command line arguments and configuration values
func filterEmptyStrings(slice []string) []string {
var result []string
for _, s := range slice {
if s != "" {
result = append(result, s)
}
}
return result
}
// ServiceCommand handles service-related operations
// This encapsulates all service management functionality for the CLI
type ServiceCommand struct {
serviceManager *ServiceManager
}
// initializeServiceManager creates a service manager with default configuration
// This sets up the basic service infrastructure needed for all service operations
func (sc *ServiceCommand) initializeServiceManager() (service.Service, *prog, error) {
svcConfig := sc.createServiceConfig()
return sc.initializeServiceManagerWithServiceConfig(svcConfig)
}
// initializeServiceManagerWithServiceConfig creates a service manager with the given configuration
// This allows for custom service configuration while maintaining the same initialization pattern
func (sc *ServiceCommand) initializeServiceManagerWithServiceConfig(svcConfig *service.Config) (service.Service, *prog, error) {
p := &prog{}
s, err := sc.newService(p, svcConfig)
if err != nil {
return nil, nil, fmt.Errorf("failed to create service: %w", err)
}
sc.serviceManager = &ServiceManager{prog: p, svc: s}
return s, p, nil
}
// newService creates a new service instance using the provided program and configuration.
// This abstracts the service creation process for different operating systems
func (sc *ServiceCommand) newService(p *prog, svcConfig *service.Config) (service.Service, error) {
s, err := newService(p, svcConfig)
if err != nil {
return nil, fmt.Errorf("failed to create service: %w", err)
}
return s, nil
}
// NewServiceCommand creates a new service command handler
// This provides a clean factory method for creating service command instances
func NewServiceCommand() *ServiceCommand {
return &ServiceCommand{}
}
// createServiceConfig creates a properly initialized service configuration
// This ensures consistent service naming and description across all platforms
func (sc *ServiceCommand) createServiceConfig() *service.Config {
return &service.Config{
Name: ctrldServiceName,
DisplayName: "Control-D Helper Service",
Description: "A highly configurable, multi-protocol DNS forwarding proxy",
Option: service.KeyValue{},
}
}
// InitServiceCmd creates the service command with proper logic and aliases
// This sets up all service-related subcommands with appropriate permissions and flags
func InitServiceCmd(rootCmd *cobra.Command) *cobra.Command {
// Create service command handlers
sc := NewServiceCommand()
startCmd, startCmdAlias := createStartCommands(sc)
rootCmd.AddCommand(startCmdAlias)
// Stop command
stopCmd := &cobra.Command{
Use: "stop",
Short: "Stop the ctrld service",
Args: cobra.NoArgs,
PreRun: func(cmd *cobra.Command, args []string) {
checkHasElevatedPrivilege()
},
RunE: sc.Stop,
}
stopCmd.Flags().StringVarP(&iface, "iface", "", "", `Reset DNS setting for iface, "auto" means the default interface gateway`)
stopCmd.Flags().Int64VarP(&deactivationPin, "pin", "", defaultDeactivationPin, `Pin code for stopping ctrld`)
_ = stopCmd.Flags().MarkHidden("pin")
// Restart command
restartCmd := &cobra.Command{
Use: "restart",
Short: "Restart the ctrld service",
Args: cobra.NoArgs,
PreRun: func(cmd *cobra.Command, args []string) {
checkHasElevatedPrivilege()
},
RunE: sc.Restart,
}
// Status command
statusCmd := &cobra.Command{
Use: "status",
Short: "Show status of the ctrld service",
Args: cobra.NoArgs,
RunE: sc.Status,
}
if runtime.GOOS == "darwin" {
// On darwin, running status command without privileges may return wrong information.
statusCmd.PreRun = func(cmd *cobra.Command, args []string) {
checkHasElevatedPrivilege()
}
}
// Reload command
reloadCmd := &cobra.Command{
Use: "reload",
Short: "Reload the ctrld service",
Args: cobra.NoArgs,
PreRun: func(cmd *cobra.Command, args []string) {
checkHasElevatedPrivilege()
},
RunE: sc.Reload,
}
// Uninstall command
uninstallCmd := &cobra.Command{
Use: "uninstall",
Short: "Stop and uninstall the ctrld service",
Long: `Stop and uninstall the ctrld service.
NOTE: Uninstalling will set DNS to values provided by DHCP.`,
Args: cobra.NoArgs,
PreRun: func(cmd *cobra.Command, args []string) {
checkHasElevatedPrivilege()
},
RunE: sc.Uninstall,
}
uninstallCmd.Flags().StringVarP(&iface, "iface", "", "", `Reset DNS setting for iface, "auto" means the default interface gateway`)
uninstallCmd.Flags().Int64VarP(&deactivationPin, "pin", "", defaultDeactivationPin, `Pin code for stopping ctrld`)
_ = uninstallCmd.Flags().MarkHidden("pin")
uninstallCmd.Flags().BoolVarP(&cleanup, "cleanup", "", false, `Removing ctrld binary and config files`)
// Interfaces command - use the existing InitInterfacesCmd function
interfacesCmd := InitInterfacesCmd(rootCmd)
stopCmdAlias := &cobra.Command{
PreRun: func(cmd *cobra.Command, args []string) {
checkHasElevatedPrivilege()
},
Use: "stop",
Short: "Quick stop service and remove DNS from interface",
RunE: func(cmd *cobra.Command, args []string) error {
if !cmd.Flags().Changed("iface") {
os.Args = append(os.Args, "--iface="+ifaceStartStop)
}
iface = ifaceStartStop
return stopCmd.RunE(cmd, args)
},
}
stopCmdAlias.Flags().StringVarP(&ifaceStartStop, "iface", "", "auto", `Reset DNS setting for iface, "auto" means the default interface gateway`)
stopCmdAlias.Flags().AddFlagSet(stopCmd.Flags())
rootCmd.AddCommand(stopCmdAlias)
// Create aliases for other service commands
restartCmdAlias := &cobra.Command{
PreRun: func(cmd *cobra.Command, args []string) {
checkHasElevatedPrivilege()
},
Use: "restart",
Short: "Restart the ctrld service",
RunE: func(cmd *cobra.Command, args []string) error {
return restartCmd.RunE(cmd, args)
},
}
rootCmd.AddCommand(restartCmdAlias)
reloadCmdAlias := &cobra.Command{
PreRun: func(cmd *cobra.Command, args []string) {
checkHasElevatedPrivilege()
},
Use: "reload",
Short: "Reload the ctrld service",
RunE: func(cmd *cobra.Command, args []string) error {
return reloadCmd.RunE(cmd, args)
},
}
rootCmd.AddCommand(reloadCmdAlias)
statusCmdAlias := &cobra.Command{
Use: "status",
Short: "Show status of the ctrld service",
Args: cobra.NoArgs,
RunE: statusCmd.RunE,
}
rootCmd.AddCommand(statusCmdAlias)
uninstallCmdAlias := &cobra.Command{
PreRun: func(cmd *cobra.Command, args []string) {
checkHasElevatedPrivilege()
},
Use: "uninstall",
Short: "Stop and uninstall the ctrld service",
Long: `Stop and uninstall the ctrld service.
NOTE: Uninstalling will set DNS to values provided by DHCP.`,
RunE: func(cmd *cobra.Command, args []string) error {
if !cmd.Flags().Changed("iface") {
os.Args = append(os.Args, "--iface="+ifaceStartStop)
}
iface = ifaceStartStop
return uninstallCmd.RunE(cmd, args)
},
}
uninstallCmdAlias.Flags().StringVarP(&ifaceStartStop, "iface", "", "auto", `Reset DNS setting for iface, "auto" means the default interface gateway`)
uninstallCmdAlias.Flags().AddFlagSet(uninstallCmd.Flags())
rootCmd.AddCommand(uninstallCmdAlias)
// Create service command
serviceCmd := &cobra.Command{
Use: "service",
Short: "Manage ctrld service",
Args: cobra.OnlyValidArgs,
}
serviceCmd.ValidArgs = make([]string, 7)
serviceCmd.ValidArgs[0] = startCmd.Use
serviceCmd.ValidArgs[1] = stopCmd.Use
serviceCmd.ValidArgs[2] = restartCmd.Use
serviceCmd.ValidArgs[3] = reloadCmd.Use
serviceCmd.ValidArgs[4] = statusCmd.Use
serviceCmd.ValidArgs[5] = uninstallCmd.Use
serviceCmd.ValidArgs[6] = interfacesCmd.Use
serviceCmd.AddCommand(startCmd)
serviceCmd.AddCommand(stopCmd)
serviceCmd.AddCommand(restartCmd)
serviceCmd.AddCommand(reloadCmd)
serviceCmd.AddCommand(statusCmd)
serviceCmd.AddCommand(uninstallCmd)
serviceCmd.AddCommand(interfacesCmd)
rootCmd.AddCommand(serviceCmd)
return serviceCmd
}