cmd

Documentation

Overview

Package cmd provides the structs and methods for building Juju commands. Commands need to provide an `Info` method that returns an Info struct.

The info struct contains: Name, Args, Purpose and a detailed description (Doc). This information is used to provide the default help for the command.

In the same package, there is `CommandBase` whose purpose is to be composed into new commands, and provides a default no-op SetFlags implementation, a default Init method that checks for no extra args, and a default Help method.

`Supercommand`s are commands that do many things, and have "sub-commands" that provide this functionality. Git and Bazaar are common examples of "supercommands". Subcommands must also provide the `Command` interface, and are registered using the `Register` method. The name and aliases are registered with the supercommand. If there is a duplicate name registered, the whole thing panics. For the time being, the only supercommand that we have is `wait-for` (https://juju.is/docs/juju/juju-wait-for) and the supercommand pattern is not going to be adopted anymore in the near future. Example: juju wait-for unit mysql/0

Supercommands need to be created with the `NewSuperCommand` function in order to provide a fully constructed object.

All supercommand instances get a help command. Every supercommand gets a help command which provides the basic help functionality to its respective subcommands.

Help topics have a `name` which is what is matched from the command line, a `short` one line description that is shown when `<cmd> help` is called, and a `long` text that is output when the topic is requested.

Index

• Variables
• func Info(i *cmd.Info) *cmd.Info
• func IsPiped(ctx *cmd.Context) bool
• func IsUserAbortedError(err error) bool
• func NewSuperCommand(p cmd.SuperCommandParams) *cmd.SuperCommand
• func UserConfirmName(verificationName string, objectType string, ctx *cmd.Context) error
• func UserConfirmYes(ctx *cmd.Context) error

Variables

var DefaultLog = &cmd.Log{
	DefaultConfig: os.Getenv(osenv.JujuLoggingConfigEnvKey),
}

DefaultLog is the default command logging implementation.

Functions

func Info

func Info(i *cmd.Info) *cmd.Info

func IsPiped

func IsPiped(ctx *cmd.Context) bool

IsPiped determines if the command was used in a pipe and, hence, it's stdin is not usable for user input.

func IsUserAbortedError

func IsUserAbortedError(err error) bool

IsUserAbortedError returns true if err is of type userAbortedError.

func NewSuperCommand

func NewSuperCommand(p cmd.SuperCommandParams) *cmd.SuperCommand

NewSuperCommand is like cmd.NewSuperCommand but it adds juju-specific functionality: - The default logging configuration is taken from the environment; - The version is configured to the current juju version; - The additional version information is sourced from juju/juju/version; - The command emits a log message when a command runs.

func UserConfirmName

func UserConfirmName(verificationName string, objectType string, ctx *cmd.Context) error

UserConfirmName returns an error if we do not read a "name" of the model/controller/etc from user input.

func UserConfirmYes

func UserConfirmYes(ctx *cmd.Context) error

UserConfirmYes returns an error if we do not read a "y" or "yes" from user input.