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4 months ago
8
Nagini wraps the famous Cobra CLI library with a fluent API and Go generics.
It supports slice values (comma-separated values) and arbitrary parsing.
It optionally binds flags to the Viper configuration library.
go get github.com/neiser/go-nagini
Showing examples/simple/main.go:
package main
import (
"log"
"github.com/neiser/go-nagini/command"
"github.com/neiser/go-nagini/flag"
)
type (
Wand string
)
func main() {
var (
myName string
favoriteWand Wand = "elder"
iAmVoldemort bool
)
command.New().
Flag(flag.New(&myName, flag.NotEmpty), flag.RegisterOptions{
Name: "my-name",
Required: true,
}).
Flag(flag.New(&favoriteWand, flag.NotEmptyTrimmed), flag.RegisterOptions{
Name: "favorite-wand",
Usage: "Specify magic wand",
}).
FlagBool(&iAmVoldemort, flag.RegisterOptions{
Name: "i-am-voldemort",
}).
Run(func() error {
if iAmVoldemort {
return command.WithExitCodeError{ExitCode: 66}
}
log.Printf("I'm %s and my favorite wand is '%s'", myName, favoriteWand)
return nil
}).
Execute()
}
Run with
go run ./examples/simple --my-name Harry
Showing examples/slice/main.go:
package main
import (
"log"
"strconv"
"github.com/neiser/go-nagini/command"
"github.com/neiser/go-nagini/flag"
)
func main() {
var (
someInts []int
)
command.New().
Flag(flag.NewSlice(&someInts, flag.ParseSliceOf(strconv.Atoi)), flag.RegisterOptions{
Name: "some-ints",
Required: true,
}).
Run(func() error {
log.Printf("Got integers: '%v'", someInts)
return nil
}).
Execute()
}
Run with
go run ./examples/slice --some-ints 5,6,7
Showing examples/subcommand/main.go:
package main
import (
"errors"
"log"
"github.com/neiser/go-nagini/command"
"github.com/neiser/go-nagini/flag"
)
var ErrCannotUseMagic = errors.New("cannot use magic")
func main() {
var (
useMagic bool
)
command.New().
FlagBool(&useMagic, flag.RegisterOptions{
Name: "use-magic",
Usage: "Use some magic, c'mon",
Persistent: true,
}).
AddCommands(
command.New().
Use("muggle").
Short("A person which cannot use magic").
Run(func() error {
if useMagic {
return ErrCannotUseMagic
}
return nil
}),
command.New().
Use("wizard").
Short("A person which may use magic").
Run(func() error {
if useMagic {
log.Printf("Abracadabra!")
}
return nil
}),
).
Execute()
}
Run with
go run ./examples/subcommand wizard --use-magic
go run ./examples/subcommand muggle --use-magic
Showing examples/viper/main.go:
package main
import (
"log"
"github.com/neiser/go-nagini/command"
"github.com/neiser/go-nagini/flag"
"github.com/spf13/viper"
)
func main() {
viper.AutomaticEnv() // tell Viper to read env
var (
gitlabToken string
)
command.New().
Flag(
flag.ViperBinding{
Value: flag.New(&gitlabToken, flag.NotEmptyTrimmed),
ConfigKey: "GITLAB_TOKEN",
},
flag.RegisterOptions{
Name: "gitlab-token",
Usage: "A secret GitLab Token",
},
).
Run(func() error {
log.Printf("Gitlab Token length '%d'", len(gitlabToken))
return nil
}).
Execute()
}
Run with
GITLAB_TOKEN=bla go run ./examples/viper
or
GITLAB_TOKEN=bla go run ./examples/viper --gitlab-token blub
Install the provided pre-commit hooks with
This library only exposes some limited feature set of Cobra. Please open an issue if you really miss something which fits well into this library. Otherwise, you can always modify the embedded *cobra.Command directly as a workaround.
