cli: nested

Back to gallery

Exhibit path: docs/examples/codegen/cli/nested/

A two-level command tree: a parent command with two subcommands. Shows how parent=<name> links subcommands to their parent and how the generated registry wires the full tree.

Input (in.go)

//go:build glacier_codegen_fixture

// Package main is the entry point for the myapp CLI.
package main

import (
	"context"
)

// MyApp is the root command.
//
// +glacier:command name=myapp
// +glacier:root
type MyApp struct{}

// Run is a no-op; subcommands do the work.
func (MyApp) Run(_ context.Context) error { return nil }

// StartCmd starts the server.
//
// +glacier:command name=start parent=myapp
type StartCmd struct {
	// Port is the TCP port to listen on.
	//
	// +glacier:default 8080
	// +glacier:short s
	Port int
}

// Run starts the server.
func (c *StartCmd) Run(_ context.Context) error {
	// implementation goes here
	return nil
}

// StopCmd stops the server gracefully.
//
// +glacier:command name=stop parent=myapp
type StopCmd struct {
	// Timeout is the graceful-shutdown timeout in seconds.
	//
	// +glacier:default 30
	Timeout int
}

// Run stops the server.
func (c *StopCmd) Run(_ context.Context) error {
	// implementation goes here
	return nil
}

Output (out.go)

//go:build glacier_codegen_fixture

// Code generated by glaciergen. DO NOT EDIT.
// Source: in.go
package main

import (
	"github.com/nathanbrophy/glacier/cli"
)

func init() {
	cli.Default.Register(
		cli.WithName("myapp"),
		cli.WithRoot(),
		cli.WithRunner(func() cli.Runner { return &MyApp{} }),
	)
	cli.Default.Register(
		cli.WithName("start"),
		cli.WithParent("myapp"),
		cli.WithRunner(func() cli.Runner { return &StartCmd{} }),
		cli.WithFlagDefault("Port", 8080),
		cli.WithFlagShort("Port", 's'),
	)
	cli.Default.Register(
		cli.WithName("stop"),
		cli.WithParent("myapp"),
		cli.WithRunner(func() cli.Runner { return &StopCmd{} }),
		cli.WithFlagDefault("Timeout", 30),
	)
}

What the generator did

• Registered the root command via +glacier:root.
• Registered StartCmd and StopCmd as children of the root using parent=myapp.
• The generated registry dispatches myapp start and myapp stop to the respective Run methods.
• +glacier:short s on StartCmd.Port emitted cli.WithFlagShort("Port", 's') in the generated file.

Related

simple all-markers glacier new command