cli

package
v0.1.0 Latest Latest
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 Go to latest Published: Nov 17, 2022 License: Apache-2.0 Imports: 10 Imported by: 8

Documentation

Overview

Package cli exposes helpers to build command-line binaries with cobra and viper.

Example (ChildCmd) 
package main

import (
	"fmt"
	"log"

	"github.com/fredbi/go-cli/cli"
	"github.com/spf13/cobra"
	"github.com/spf13/pflag"
	"github.com/spf13/viper"
)

// config key mappings
const (
	keyLog      = "app.log.level"
	keyURL      = "app.url"
	keyParallel = "app.parallel"
	keyUser     = "app.user"
	keyWorkers  = "app.child.workers"
	keyDry      = "run.dryRun"
)

// globalFlags captures CLI flags.
//
// In this example, we prefer to control over where the flag values are stored.
//
// This is not needed if all configuration is bound to viper.
var globalFlags cliFlags

type (
	cliFlags struct {
		DryRun   bool
		URL      string
		Parallel int
		User     string
		LogLevel string

		Child childFlags
	}

	childFlags struct {
		Workers int
	}
)

// Default values for flags.
func (f cliFlags) Defaults() cliFlags {
	return cliFlags{
		URL:      "https://www.example.com",
		Parallel: 2,
		LogLevel: "info",
		Child: childFlags{
			Workers: 5,
		},
	}
}

// applyDefaults set default values for the config. It is consistent with flag defaults.
func (f cliFlags) applyDefaults(cfg *viper.Viper) {
	cfg.SetDefault(keyURL, globalFlags.Defaults().URL)
	cfg.SetDefault(keyParallel, globalFlags.Defaults().Parallel)
	cfg.SetDefault(keyLog, globalFlags.Defaults().LogLevel)
	cfg.SetDefault(keyWorkers, globalFlags.Defaults().Child.Workers)
}

// root command execution
func rootRunFunc(c *cobra.Command, _ []string) error {
	cfg := cli.ConfigFromContext(c.Context())
	if cfg == nil {
		cli.Die("failed to retrieve config")
	}

	fmt.Println(
		"example called\n",
		fmt.Sprintf("URL config: %s\n", cfg.GetString(keyURL)),
		fmt.Sprintf("log level config: %s\n", cfg.GetString(keyLog)),
		fmt.Sprintf("parallel config: %d\n", cfg.GetInt(keyParallel)),
		fmt.Sprintf("user config: %s\n", cfg.GetString(keyUser)),
	)

	fmt.Println(
		"global flags values evaluated by root\n",
		fmt.Sprintf("%#v", globalFlags),
	)

	return nil
}

// child command execution
func childRunFunc(c *cobra.Command, _ []string) error {
	cfg := cli.ConfigFromContext(c.Context())

	fmt.Println(
		"subcommand called\n",
		fmt.Sprintf("URL config: %s\n", cfg.GetString(keyURL)),
		fmt.Sprintf("parallel config: %d\n", cfg.GetInt(keyParallel)),
		fmt.Sprintf("user config: %s\n", cfg.GetString(keyUser)),
		fmt.Sprintf("workers config: %s\n", cfg.GetString(keyWorkers)),
	)

	fmt.Println(
		"global flags values evaluated by child\n",
		fmt.Sprintf("%#v", globalFlags),
	)

	return nil
}

func emptyRunFunc(c *cobra.Command, _ []string) error {
	cfg := cli.ConfigFromContext(c.Context())

	fmt.Println("command called:", c.Name())
	fmt.Println("injected config:", cfg.AllSettings())

	return nil
}

/*
target:

	func Execute() error {
		return cli.NewCommand(
			&cobra.Command{},
			cli.WithConfigurator(
				cli.Config(globalFlags.applyDefaults),
			),
			cli.WithTypedFlag(...),
			cli.WithTypedPersistentFlag(&globalFlags.LogLevel, "log-level", globalFlags.Default().LogLevel, "Controls logging verbosity"),
			cli.WithSubCommands(
				cli.NewComand(
					&cobra.Command{
						...
					},
					cli.WithTypedFlags(...),
				),
			),
		).Execute()
	}
*/
func RootCmd() *cli.Command {
	return cli.NewCommand(
		&cobra.Command{
			Use:   "example",
			Short: "examplifies a cobra command",
			Long:  "...",
			RunE:  rootRunFunc,
		},
		cli.WithFlag(&globalFlags.DryRun, "dry-run", globalFlags.Defaults().DryRun, "Dry run",
			cli.BindFlagToConfig(keyDry),
		),
		cli.WithPersistentFlag(&globalFlags.LogLevel, "log-level", globalFlags.Defaults().LogLevel, "Controls logging verbosity",
			cli.BindFlagToConfig(keyLog),
		),
		cli.WithPersistentFlag(&globalFlags.URL, "url", globalFlags.Defaults().URL, "The URL to connect to",
			cli.BindFlagToConfig(keyURL),
		),
		cli.WithPersistentFlagP(&globalFlags.Parallel, "parallel", "p", globalFlags.Defaults().Parallel, "Degree of parallelism",
			cli.BindFlagToConfig(keyParallel),
		),

		cli.WithPersistentFlagFunc(func(flags *pflag.FlagSet) string {
			const userFlag = "user"
			flags.StringVar(&globalFlags.User, userFlag, globalFlags.Defaults().User, "Originating user")
			return userFlag
		},
			cli.FlagIsRequired(), cli.BindFlagToConfig(keyUser),
		),
		cli.WithSubCommands(
			cli.NewCommand(
				&cobra.Command{
					Use:   "child",
					Short: "sub-command example",
					Long:  "...",
					RunE:  childRunFunc,
				},
				cli.WithFlag(&globalFlags.Child.Workers, "workers", globalFlags.Defaults().Child.Workers, "Number of workers threads",
					cli.FlagIsRequired(),
					cli.BindFlagToConfig(keyWorkers),
				),
				cli.WithSubCommands(
					cli.NewCommand(
						&cobra.Command{
							Use:   "grandchild",
							Short: "sub-sub-command example",
							Long:  "...",
							RunE:  emptyRunFunc,
						},
					),
				),
			),
			cli.NewCommand(
				&cobra.Command{
					Use:   "version",
					Short: "another sub-command example",
					Long:  "...",
					RunE:  emptyRunFunc,
				},
			),
		),

		cli.WithConfig(cli.Config(globalFlags.applyDefaults)),
	)
}

func main() {
	rootCmd := RootCmd()
	if err := rootCmd.ExecuteWithArgs(
		"child",
		"--parallel",
		"20",
		"--url",
		"https://www.zorg.com",
		"--user",
		"zorg",
		"--workers",
		"12",
	); err != nil {
		log.Fatal("executing:", err)
	}

	fmt.Println("done")

}

Output:

subcommand called
 URL config: https://www.zorg.com
 parallel config: 20
 user config: zorg
 workers config: 12

global flags values evaluated by child
 cli_test.cliFlags{DryRun:false, URL:"https://www.zorg.com", Parallel:20, User:"zorg", LogLevel:"info", Child:cli_test.childFlags{Workers:12}}
done
Example (Help) 
package main

import (
	"fmt"
	"log"

	"github.com/fredbi/go-cli/cli"
	"github.com/spf13/cobra"
	"github.com/spf13/pflag"
	"github.com/spf13/viper"
)

// config key mappings
const (
	keyLog      = "app.log.level"
	keyURL      = "app.url"
	keyParallel = "app.parallel"
	keyUser     = "app.user"
	keyWorkers  = "app.child.workers"
	keyDry      = "run.dryRun"
)

// globalFlags captures CLI flags.
//
// In this example, we prefer to control over where the flag values are stored.
//
// This is not needed if all configuration is bound to viper.
var globalFlags cliFlags

type (
	cliFlags struct {
		DryRun   bool
		URL      string
		Parallel int
		User     string
		LogLevel string

		Child childFlags
	}

	childFlags struct {
		Workers int
	}
)

// Default values for flags.
func (f cliFlags) Defaults() cliFlags {
	return cliFlags{
		URL:      "https://www.example.com",
		Parallel: 2,
		LogLevel: "info",
		Child: childFlags{
			Workers: 5,
		},
	}
}

// applyDefaults set default values for the config. It is consistent with flag defaults.
func (f cliFlags) applyDefaults(cfg *viper.Viper) {
	cfg.SetDefault(keyURL, globalFlags.Defaults().URL)
	cfg.SetDefault(keyParallel, globalFlags.Defaults().Parallel)
	cfg.SetDefault(keyLog, globalFlags.Defaults().LogLevel)
	cfg.SetDefault(keyWorkers, globalFlags.Defaults().Child.Workers)
}

// root command execution
func rootRunFunc(c *cobra.Command, _ []string) error {
	cfg := cli.ConfigFromContext(c.Context())
	if cfg == nil {
		cli.Die("failed to retrieve config")
	}

	fmt.Println(
		"example called\n",
		fmt.Sprintf("URL config: %s\n", cfg.GetString(keyURL)),
		fmt.Sprintf("log level config: %s\n", cfg.GetString(keyLog)),
		fmt.Sprintf("parallel config: %d\n", cfg.GetInt(keyParallel)),
		fmt.Sprintf("user config: %s\n", cfg.GetString(keyUser)),
	)

	fmt.Println(
		"global flags values evaluated by root\n",
		fmt.Sprintf("%#v", globalFlags),
	)

	return nil
}

// child command execution
func childRunFunc(c *cobra.Command, _ []string) error {
	cfg := cli.ConfigFromContext(c.Context())

	fmt.Println(
		"subcommand called\n",
		fmt.Sprintf("URL config: %s\n", cfg.GetString(keyURL)),
		fmt.Sprintf("parallel config: %d\n", cfg.GetInt(keyParallel)),
		fmt.Sprintf("user config: %s\n", cfg.GetString(keyUser)),
		fmt.Sprintf("workers config: %s\n", cfg.GetString(keyWorkers)),
	)

	fmt.Println(
		"global flags values evaluated by child\n",
		fmt.Sprintf("%#v", globalFlags),
	)

	return nil
}

func emptyRunFunc(c *cobra.Command, _ []string) error {
	cfg := cli.ConfigFromContext(c.Context())

	fmt.Println("command called:", c.Name())
	fmt.Println("injected config:", cfg.AllSettings())

	return nil
}

/*
target:

	func Execute() error {
		return cli.NewCommand(
			&cobra.Command{},
			cli.WithConfigurator(
				cli.Config(globalFlags.applyDefaults),
			),
			cli.WithTypedFlag(...),
			cli.WithTypedPersistentFlag(&globalFlags.LogLevel, "log-level", globalFlags.Default().LogLevel, "Controls logging verbosity"),
			cli.WithSubCommands(
				cli.NewComand(
					&cobra.Command{
						...
					},
					cli.WithTypedFlags(...),
				),
			),
		).Execute()
	}
*/
func RootCmd() *cli.Command {
	return cli.NewCommand(
		&cobra.Command{
			Use:   "example",
			Short: "examplifies a cobra command",
			Long:  "...",
			RunE:  rootRunFunc,
		},
		cli.WithFlag(&globalFlags.DryRun, "dry-run", globalFlags.Defaults().DryRun, "Dry run",
			cli.BindFlagToConfig(keyDry),
		),
		cli.WithPersistentFlag(&globalFlags.LogLevel, "log-level", globalFlags.Defaults().LogLevel, "Controls logging verbosity",
			cli.BindFlagToConfig(keyLog),
		),
		cli.WithPersistentFlag(&globalFlags.URL, "url", globalFlags.Defaults().URL, "The URL to connect to",
			cli.BindFlagToConfig(keyURL),
		),
		cli.WithPersistentFlagP(&globalFlags.Parallel, "parallel", "p", globalFlags.Defaults().Parallel, "Degree of parallelism",
			cli.BindFlagToConfig(keyParallel),
		),

		cli.WithPersistentFlagFunc(func(flags *pflag.FlagSet) string {
			const userFlag = "user"
			flags.StringVar(&globalFlags.User, userFlag, globalFlags.Defaults().User, "Originating user")
			return userFlag
		},
			cli.FlagIsRequired(), cli.BindFlagToConfig(keyUser),
		),
		cli.WithSubCommands(
			cli.NewCommand(
				&cobra.Command{
					Use:   "child",
					Short: "sub-command example",
					Long:  "...",
					RunE:  childRunFunc,
				},
				cli.WithFlag(&globalFlags.Child.Workers, "workers", globalFlags.Defaults().Child.Workers, "Number of workers threads",
					cli.FlagIsRequired(),
					cli.BindFlagToConfig(keyWorkers),
				),
				cli.WithSubCommands(
					cli.NewCommand(
						&cobra.Command{
							Use:   "grandchild",
							Short: "sub-sub-command example",
							Long:  "...",
							RunE:  emptyRunFunc,
						},
					),
				),
			),
			cli.NewCommand(
				&cobra.Command{
					Use:   "version",
					Short: "another sub-command example",
					Long:  "...",
					RunE:  emptyRunFunc,
				},
			),
		),

		cli.WithConfig(cli.Config(globalFlags.applyDefaults)),
	)
}

func main() {
	rootCmd := RootCmd()
	rootCmd.SetArgs([]string{
		"--help",
	})

	if err := rootCmd.Execute(); err != nil {
		log.Fatal("executing:", err)
	}

	fmt.Println("done")

}

Output:

	...

Usage:
  example [flags]
  example [command]

Available Commands:
  child       sub-command example
  completion  Generate the autocompletion script for the specified shell
  help        Help about any command
  version     another sub-command example

Flags:
      --dry-run            Dry run
  -h, --help               help for example
      --log-level string   Controls logging verbosity (default "info")
  -p, --parallel int       Degree of parallelism (default 2)
      --url string         The URL to connect to (default "https://www.example.com")
      --user string        Originating user

Use "example [command] --help" for more information about a command.
done
Example (PrintCmd) 
package main

import (
	"fmt"

	"github.com/fredbi/go-cli/cli"
	"github.com/spf13/cobra"
	"github.com/spf13/pflag"
	"github.com/spf13/viper"
)

// config key mappings
const (
	keyLog      = "app.log.level"
	keyURL      = "app.url"
	keyParallel = "app.parallel"
	keyUser     = "app.user"
	keyWorkers  = "app.child.workers"
	keyDry      = "run.dryRun"
)

// globalFlags captures CLI flags.
//
// In this example, we prefer to control over where the flag values are stored.
//
// This is not needed if all configuration is bound to viper.
var globalFlags cliFlags

type (
	cliFlags struct {
		DryRun   bool
		URL      string
		Parallel int
		User     string
		LogLevel string

		Child childFlags
	}

	childFlags struct {
		Workers int
	}
)

// Default values for flags.
func (f cliFlags) Defaults() cliFlags {
	return cliFlags{
		URL:      "https://www.example.com",
		Parallel: 2,
		LogLevel: "info",
		Child: childFlags{
			Workers: 5,
		},
	}
}

// applyDefaults set default values for the config. It is consistent with flag defaults.
func (f cliFlags) applyDefaults(cfg *viper.Viper) {
	cfg.SetDefault(keyURL, globalFlags.Defaults().URL)
	cfg.SetDefault(keyParallel, globalFlags.Defaults().Parallel)
	cfg.SetDefault(keyLog, globalFlags.Defaults().LogLevel)
	cfg.SetDefault(keyWorkers, globalFlags.Defaults().Child.Workers)
}

// root command execution
func rootRunFunc(c *cobra.Command, _ []string) error {
	cfg := cli.ConfigFromContext(c.Context())
	if cfg == nil {
		cli.Die("failed to retrieve config")
	}

	fmt.Println(
		"example called\n",
		fmt.Sprintf("URL config: %s\n", cfg.GetString(keyURL)),
		fmt.Sprintf("log level config: %s\n", cfg.GetString(keyLog)),
		fmt.Sprintf("parallel config: %d\n", cfg.GetInt(keyParallel)),
		fmt.Sprintf("user config: %s\n", cfg.GetString(keyUser)),
	)

	fmt.Println(
		"global flags values evaluated by root\n",
		fmt.Sprintf("%#v", globalFlags),
	)

	return nil
}

// child command execution
func childRunFunc(c *cobra.Command, _ []string) error {
	cfg := cli.ConfigFromContext(c.Context())

	fmt.Println(
		"subcommand called\n",
		fmt.Sprintf("URL config: %s\n", cfg.GetString(keyURL)),
		fmt.Sprintf("parallel config: %d\n", cfg.GetInt(keyParallel)),
		fmt.Sprintf("user config: %s\n", cfg.GetString(keyUser)),
		fmt.Sprintf("workers config: %s\n", cfg.GetString(keyWorkers)),
	)

	fmt.Println(
		"global flags values evaluated by child\n",
		fmt.Sprintf("%#v", globalFlags),
	)

	return nil
}

func emptyRunFunc(c *cobra.Command, _ []string) error {
	cfg := cli.ConfigFromContext(c.Context())

	fmt.Println("command called:", c.Name())
	fmt.Println("injected config:", cfg.AllSettings())

	return nil
}

/*
target:

	func Execute() error {
		return cli.NewCommand(
			&cobra.Command{},
			cli.WithConfigurator(
				cli.Config(globalFlags.applyDefaults),
			),
			cli.WithTypedFlag(...),
			cli.WithTypedPersistentFlag(&globalFlags.LogLevel, "log-level", globalFlags.Default().LogLevel, "Controls logging verbosity"),
			cli.WithSubCommands(
				cli.NewComand(
					&cobra.Command{
						...
					},
					cli.WithTypedFlags(...),
				),
			),
		).Execute()
	}
*/
func RootCmd() *cli.Command {
	return cli.NewCommand(
		&cobra.Command{
			Use:   "example",
			Short: "examplifies a cobra command",
			Long:  "...",
			RunE:  rootRunFunc,
		},
		cli.WithFlag(&globalFlags.DryRun, "dry-run", globalFlags.Defaults().DryRun, "Dry run",
			cli.BindFlagToConfig(keyDry),
		),
		cli.WithPersistentFlag(&globalFlags.LogLevel, "log-level", globalFlags.Defaults().LogLevel, "Controls logging verbosity",
			cli.BindFlagToConfig(keyLog),
		),
		cli.WithPersistentFlag(&globalFlags.URL, "url", globalFlags.Defaults().URL, "The URL to connect to",
			cli.BindFlagToConfig(keyURL),
		),
		cli.WithPersistentFlagP(&globalFlags.Parallel, "parallel", "p", globalFlags.Defaults().Parallel, "Degree of parallelism",
			cli.BindFlagToConfig(keyParallel),
		),

		cli.WithPersistentFlagFunc(func(flags *pflag.FlagSet) string {
			const userFlag = "user"
			flags.StringVar(&globalFlags.User, userFlag, globalFlags.Defaults().User, "Originating user")
			return userFlag
		},
			cli.FlagIsRequired(), cli.BindFlagToConfig(keyUser),
		),
		cli.WithSubCommands(
			cli.NewCommand(
				&cobra.Command{
					Use:   "child",
					Short: "sub-command example",
					Long:  "...",
					RunE:  childRunFunc,
				},
				cli.WithFlag(&globalFlags.Child.Workers, "workers", globalFlags.Defaults().Child.Workers, "Number of workers threads",
					cli.FlagIsRequired(),
					cli.BindFlagToConfig(keyWorkers),
				),
				cli.WithSubCommands(
					cli.NewCommand(
						&cobra.Command{
							Use:   "grandchild",
							Short: "sub-sub-command example",
							Long:  "...",
							RunE:  emptyRunFunc,
						},
					),
				),
			),
			cli.NewCommand(
				&cobra.Command{
					Use:   "version",
					Short: "another sub-command example",
					Long:  "...",
					RunE:  emptyRunFunc,
				},
			),
		),

		cli.WithConfig(cli.Config(globalFlags.applyDefaults)),
	)
}

func main() {
	rootCmd := RootCmd()

	fmt.Println(rootCmd.String())

}

Output:

example
 child
  grandchild
 version
Example (RootCmd) 
package main

import (
	"fmt"
	"log"

	"github.com/fredbi/go-cli/cli"
	"github.com/spf13/cobra"
	"github.com/spf13/pflag"
	"github.com/spf13/viper"
)

// config key mappings
const (
	keyLog      = "app.log.level"
	keyURL      = "app.url"
	keyParallel = "app.parallel"
	keyUser     = "app.user"
	keyWorkers  = "app.child.workers"
	keyDry      = "run.dryRun"
)

// globalFlags captures CLI flags.
//
// In this example, we prefer to control over where the flag values are stored.
//
// This is not needed if all configuration is bound to viper.
var globalFlags cliFlags

type (
	cliFlags struct {
		DryRun   bool
		URL      string
		Parallel int
		User     string
		LogLevel string

		Child childFlags
	}

	childFlags struct {
		Workers int
	}
)

// Default values for flags.
func (f cliFlags) Defaults() cliFlags {
	return cliFlags{
		URL:      "https://www.example.com",
		Parallel: 2,
		LogLevel: "info",
		Child: childFlags{
			Workers: 5,
		},
	}
}

// applyDefaults set default values for the config. It is consistent with flag defaults.
func (f cliFlags) applyDefaults(cfg *viper.Viper) {
	cfg.SetDefault(keyURL, globalFlags.Defaults().URL)
	cfg.SetDefault(keyParallel, globalFlags.Defaults().Parallel)
	cfg.SetDefault(keyLog, globalFlags.Defaults().LogLevel)
	cfg.SetDefault(keyWorkers, globalFlags.Defaults().Child.Workers)
}

// root command execution
func rootRunFunc(c *cobra.Command, _ []string) error {
	cfg := cli.ConfigFromContext(c.Context())
	if cfg == nil {
		cli.Die("failed to retrieve config")
	}

	fmt.Println(
		"example called\n",
		fmt.Sprintf("URL config: %s\n", cfg.GetString(keyURL)),
		fmt.Sprintf("log level config: %s\n", cfg.GetString(keyLog)),
		fmt.Sprintf("parallel config: %d\n", cfg.GetInt(keyParallel)),
		fmt.Sprintf("user config: %s\n", cfg.GetString(keyUser)),
	)

	fmt.Println(
		"global flags values evaluated by root\n",
		fmt.Sprintf("%#v", globalFlags),
	)

	return nil
}

// child command execution
func childRunFunc(c *cobra.Command, _ []string) error {
	cfg := cli.ConfigFromContext(c.Context())

	fmt.Println(
		"subcommand called\n",
		fmt.Sprintf("URL config: %s\n", cfg.GetString(keyURL)),
		fmt.Sprintf("parallel config: %d\n", cfg.GetInt(keyParallel)),
		fmt.Sprintf("user config: %s\n", cfg.GetString(keyUser)),
		fmt.Sprintf("workers config: %s\n", cfg.GetString(keyWorkers)),
	)

	fmt.Println(
		"global flags values evaluated by child\n",
		fmt.Sprintf("%#v", globalFlags),
	)

	return nil
}

func emptyRunFunc(c *cobra.Command, _ []string) error {
	cfg := cli.ConfigFromContext(c.Context())

	fmt.Println("command called:", c.Name())
	fmt.Println("injected config:", cfg.AllSettings())

	return nil
}

/*
target:

	func Execute() error {
		return cli.NewCommand(
			&cobra.Command{},
			cli.WithConfigurator(
				cli.Config(globalFlags.applyDefaults),
			),
			cli.WithTypedFlag(...),
			cli.WithTypedPersistentFlag(&globalFlags.LogLevel, "log-level", globalFlags.Default().LogLevel, "Controls logging verbosity"),
			cli.WithSubCommands(
				cli.NewComand(
					&cobra.Command{
						...
					},
					cli.WithTypedFlags(...),
				),
			),
		).Execute()
	}
*/
func RootCmd() *cli.Command {
	return cli.NewCommand(
		&cobra.Command{
			Use:   "example",
			Short: "examplifies a cobra command",
			Long:  "...",
			RunE:  rootRunFunc,
		},
		cli.WithFlag(&globalFlags.DryRun, "dry-run", globalFlags.Defaults().DryRun, "Dry run",
			cli.BindFlagToConfig(keyDry),
		),
		cli.WithPersistentFlag(&globalFlags.LogLevel, "log-level", globalFlags.Defaults().LogLevel, "Controls logging verbosity",
			cli.BindFlagToConfig(keyLog),
		),
		cli.WithPersistentFlag(&globalFlags.URL, "url", globalFlags.Defaults().URL, "The URL to connect to",
			cli.BindFlagToConfig(keyURL),
		),
		cli.WithPersistentFlagP(&globalFlags.Parallel, "parallel", "p", globalFlags.Defaults().Parallel, "Degree of parallelism",
			cli.BindFlagToConfig(keyParallel),
		),

		cli.WithPersistentFlagFunc(func(flags *pflag.FlagSet) string {
			const userFlag = "user"
			flags.StringVar(&globalFlags.User, userFlag, globalFlags.Defaults().User, "Originating user")
			return userFlag
		},
			cli.FlagIsRequired(), cli.BindFlagToConfig(keyUser),
		),
		cli.WithSubCommands(
			cli.NewCommand(
				&cobra.Command{
					Use:   "child",
					Short: "sub-command example",
					Long:  "...",
					RunE:  childRunFunc,
				},
				cli.WithFlag(&globalFlags.Child.Workers, "workers", globalFlags.Defaults().Child.Workers, "Number of workers threads",
					cli.FlagIsRequired(),
					cli.BindFlagToConfig(keyWorkers),
				),
				cli.WithSubCommands(
					cli.NewCommand(
						&cobra.Command{
							Use:   "grandchild",
							Short: "sub-sub-command example",
							Long:  "...",
							RunE:  emptyRunFunc,
						},
					),
				),
			),
			cli.NewCommand(
				&cobra.Command{
					Use:   "version",
					Short: "another sub-command example",
					Long:  "...",
					RunE:  emptyRunFunc,
				},
			),
		),

		cli.WithConfig(cli.Config(globalFlags.applyDefaults)),
	)
}

func main() {
	rootCmd := RootCmd()
	rootCmd.SetArgs([]string{
		"--dry-run",
		"--log-level",
		"debug",
		"--parallel",
		"15",
		"--user",
		"fred",
	},
	)

	if err := rootCmd.Execute(); err != nil {
		log.Fatal("executing:", err)
	}

	fmt.Println("done")

}

Output:

example called
 URL config: https://www.example.com
 log level config: debug
 parallel config: 15
 user config: fred

global flags values evaluated by root
 cli_test.cliFlags{DryRun:true, URL:"https://www.example.com", Parallel:15, User:"fred", LogLevel:"debug", Child:cli_test.childFlags{Workers:5}}
done

Index

Examples

Constants

This section is empty.

Variables

View Source 
var (

	// ConfigEnv defines the environment variable used by the Config() function
	// to find the current environment.
	ConfigEnv = "CONFIG_ENV"

	// ConfigDebugEnv defines the environment variable used to instruct the config loader
	// to dump all config keys for debugging.
	ConfigDebugEnv = "DEBUG_CONFIG"
)

Functions

func Config 

func Config(defaulters ...func(*viper.Viper)) *viper.Viper

Config calls ConfigForEnv, with the current environment resolved from the variable "CONFIG_ENV".

func ConfigForEnv 

func ConfigForEnv(env string, defaulters ...func(*viper.Viper)) *viper.Viper

ConfigForEnv loads and merge a set of config files for a given environment and applies some defaults,

It assumes that config files follow the conventions defined by "github.com/fredbi/go-cli/config".

It dies upon failure.

Environment variable settings

  • If the environment variable "DEBUG_CONFIG" is set, the loaded settings are dumped to standard output as JSON.
  • The environment variable "CONFIG_DIR" defines the folder where the root configuration is located.

func ConfigFromContext 

func ConfigFromContext(ctx context.Context) *viper.Viper

ConfigFromContext retrieves a configuration registry from the context.

func ContextWithConfig 

func ContextWithConfig(ctx context.Context, cfg *viper.Viper) context.Context

ContextWithConfig puts a configuration registry in the context.

func Die 

func Die(format string, args ...any)

Die exits the current process with some final croak.

This wraps log.Fatal for convenient testing.

func Must 

func Must(err error)

Must panic on error.

func MustBindFromFlagSet 

func MustBindFromFlagSet(cfg *viper.Viper, key, flagName string, flags *pflag.FlagSet)

MustBindFromFlagSet binds a key in a *viper.Viper registry to command-line flag found in a flag set (*pflag.FlagSet).

Dies on error. This happens if the flag set is nil or if the requested flag has not been registered in the flag set yet.

func MustBindPFlag 

func MustBindPFlag(cfg *viper.Viper, key string, flag *pflag.Flag)

MustBindPlag binds a key in a *viper.Viper registry to a command-line flag (*pflag.Flag).

Dies on error. This happens if the flag is nil.

func SetConfigOptions 

func SetConfigOptions(opts ...config.Option)

SetConfigOption defines package-level defaults for config options, when using ConfigForEnv or Config.

By default, this package sets no option and uses all defaults from the config package.

func SetDie 

func SetDie(fatalFunc func(string, ...any))

SetDie alters the package level log.Fatalf implementation.

This should be used for testing only.

Types

type Command 

type Command struct {
	*cobra.Command
	// contains filtered or unexported fields
}

Command wraps a *cobra.Command with some options to register and bind flags and config more easily.

func NewCommand 

func NewCommand(cmd *cobra.Command, opts ...Option) *Command

NewCommand builds a new Command wrapping a *cobra.Command.

func (*Command) AddCommand 

func (c *Command) AddCommand(subs ...*Command)

AddCommand adds child command(s).

func (*Command) BindFlags 

func (c *Command) BindFlags()

BindFlags binds the command-line flags marked as such to the configuration registry.

This applies recursively to all sub-commands.

It doesn't perform anything if no flags or no config are set for the command (use the options WithFlag() and WithConfig())

func (*Command) Commands 

func (c *Command) Commands() []*Command

Commands returns the child commands.

func (*Command) Config 

func (c *Command) Config() *viper.Viper

Config returns the viper config registry shared by the command tree.

func (*Command) ExecuteContext 

func (c *Command) ExecuteContext(ctx context.Context) error

ExecuteContext wraps cobra.Command.ExecuteContext() by ensuring the config is in the context.

func (*Command) ExecuteWithArgs 

func (c *Command) ExecuteWithArgs(args ...string) error

ExecuteWithArgs is a convenience wrapper to execute a command with preset args.

This is primarily intended for testing commands.

func (*Command) RegisterFlags 

func (c *Command) RegisterFlags()

Register command-line flags for this command.

func (*Command) String 

func (c *Command) String() string

String provides a short text representation of the command subtree.

type FlagOption 

type FlagOption func(*flagOption)

func BindFlagToConfig 

func BindFlagToConfig(key string) FlagOption

BindFlagToConfig declares the flag as bound to a configuration key in the viper registry.

func FlagIsRequired 

func FlagIsRequired() FlagOption

FlagIsRequired declares the flag as required for the command.

type Option 

type Option func(*options)

Option configures a Command.

func WithConfig 

func WithConfig(cfg *viper.Viper) Option

WithConfig adds a viper.Viper configuration to the command tree.

func WithFlag 

func WithFlag[T gflag.FlaggablePrimitives | gflag.FlaggableTypes](addr *T, name string, defaultValue T, usage string, opts ...FlagOption) Option

TODO: with/without flag address WithFlag declares a flag of any type supported by gflag, with some options.

func WithFlagFunc 

func WithFlagFunc(regFunc RegisterFunc, opts ...FlagOption) Option

WithFlagFunc declares a command flag using a RegisterFunc function and some flag options.

func WithFlagP 

func WithFlagP[T gflag.FlaggablePrimitives | gflag.FlaggableTypes](addr *T, name, short string, defaultValue T, usage string, opts ...FlagOption) Option

WithFlagP declares a flag of any type supported by gflag, with a short name and some options.

func WithPersistentFlag 

func WithPersistentFlag[T gflag.FlaggablePrimitives | gflag.FlaggableTypes](addr *T, name string, defaultValue T, usage string, opts ...FlagOption) Option

WithPersistentFlag declares a persistent flag of any type supported by gflag, with some options.

func WithPersistentFlagFunc 

func WithPersistentFlagFunc(regFunc RegisterFunc, opts ...FlagOption) Option

WithPersistentFlagFunc declares a persistent flag for the command using a RegisterFunc function and some flag options.

func WithPersistentFlagP 

func WithPersistentFlagP[T gflag.FlaggablePrimitives | gflag.FlaggableTypes](addr *T, name, short string, defaultValue T, usage string, opts ...FlagOption) Option

WithPersistentFlagP declares a persistent flag of any type supported by gflag, with a short name and some options.

func WithPersistentSliceFlag 

func WithPersistentSliceFlag[T gflag.FlaggablePrimitives | gflag.FlaggableTypes](addr *[]T, name string, defaultValue []T, usage string, opts ...FlagOption) Option

WithPersistentSliceFlag declares a persistent flag of any slice type supported by gflag, with some options.

func WithPersistentSliceFlagP 

func WithPersistentSliceFlagP[T gflag.FlaggablePrimitives | gflag.FlaggableTypes](addr *[]T, name, short string, defaultValue []T, usage string, opts ...FlagOption) Option

WithPersistentSliceFlagP declares a persistent flag of any type supported by gflag, with a short name and some options.

func WithSliceFlag 

func WithSliceFlag[T gflag.FlaggablePrimitives | gflag.FlaggableTypes](addr *[]T, name string, defaultValue []T, usage string, opts ...FlagOption) Option

WithSliceFlag declares a flag of any slice type supported by gflag, with some options.

func WithSliceFlagP 

func WithSliceFlagP[T gflag.FlaggablePrimitives | gflag.FlaggableTypes](addr *[]T, name, short string, defaultValue []T, usage string, opts ...FlagOption) Option

WithSliceFlagP declares a flag of any slice type supported by gflag, with a short name and some options.

func WithSubCommands 

func WithSubCommands(subs ...*Command) Option

WithSubCommands adds child commands.

type RegisterFunc 

type RegisterFunc func(*pflag.FlagSet) string

RegisterFunc registers a flag to a provided pflag.FlagSet and returns the flag name.

Source Files

View all Source files

Directories

Path Synopsis
Package gflag exposes generic types to deal with flags.
 Package gflag exposes generic types to deal with flags.
extensions
Package extensions provides extensions to the github.com/spf13/pflag package.
 Package extensions provides extensions to the github.com/spf13/pflag package.

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