open-consul/command/registry.go

63 lines
1.6 KiB
Go
Raw Normal View History

package command
import (
"fmt"
"os"
"os/signal"
"syscall"
mcli "github.com/mitchellh/cli"
"github.com/hashicorp/consul/command/cli"
)
// Factory is a function that returns a new instance of a CLI-sub command.
type Factory func(cli.Ui) (cli.Command, error)
// Register adds a new CLI sub-command to the registry.
func Register(name string, fn Factory) {
if registry == nil {
registry = make(map[string]Factory)
}
if registry[name] != nil {
panic(fmt.Errorf("Command %q is already registered", name))
}
registry[name] = fn
}
// CommandsFromRegistry returns a realized mapping of available CLI commands in a format that
// the CLI class can consume. This should be called after all registration is
// complete.
func CommandsFromRegistry(ui cli.Ui) map[string]mcli.CommandFactory {
m := make(map[string]mcli.CommandFactory)
for name, fn := range registry {
thisFn := fn
m[name] = func() (mcli.Command, error) {
return thisFn(ui)
}
}
return m
}
// registry has an entry for each available CLI sub-command, indexed by sub
// command name. This should be populated at package init() time via Register().
var registry map[string]Factory
// MakeShutdownCh returns a channel that can be used for shutdown notifications
// for commands. This channel will send a message for every interrupt or SIGTERM
// received.
func MakeShutdownCh() <-chan struct{} {
resultCh := make(chan struct{})
signalCh := make(chan os.Signal, 4)
signal.Notify(signalCh, os.Interrupt, syscall.SIGTERM)
go func() {
for {
<-signalCh
resultCh <- struct{}{}
}
}()
return resultCh
}