Make a cobra Command flag required
A few months ago this behavior was changed in cobra
, although the documentation is not very clear on this. Now if you mark a flag as MarkFlagRequired("primary-ip")
and you don't supply such a flag, running the command will print the help plus
required flag(s) "primary-ip"
exit status 1
at the end where the missing required flags are stated.
No, you have to check yourself whether the input is correct for your program.
Note that this makes sense, since you may want to check if the input is correct at the same time. In your example you should check if the input exists AND if the input is a valid ip-address.
Late but i hope this help you !
First of all, we need to know that cobra
defines two types of flags.
Persistent flags: they will be available to the command and every sub-command under it.
Local flags: they will available only to the specific command which define them.
So cobra
provides two approaches to make flags required regarding the type of the flag.
On the init
function of your command, it could be the root
or any other command or sub-command. Lets create a cli app called my-cmd
with a sub-command called xD sub-command
// root.go file
var Foo bool
func init() {
cobra.OnInitialize(initConfig)
// define required persistent flag
myCmd.PersistentFlags().BoolVarP(&Foo, "foo", "f", false, "set foo (*)")
myCmd.MarkPersistentFlagRequired("foo")
}
// subCommand.go file
var Bar string
func init() {
// just add subCmd as a sub-command of my-cmd
myCmd.AddCommand(subCmd)
// define required local flag
subCmd.Flags().StringVarP(&Bar, "bar", "b", "", "set bar (*)")
subCmd.MarkFlagRequired("bar")
}
When you call your command in the CLI
# if you don't pass a value for 'foo' flag
> my-cmd
required flag(s) "foo" not set
exit status 1
# here you must pass a value for 'foo' because is persistent as well as 'bar' because is local for sub-cmd
> my-cmd sub-cmd
required flag(s) "foo", "bar" not set
exit status 1
cmd.Flags().StringVarP(&var, "var", "r", "", "")
cmd.MarkFlagRequired("var")