Create a v1 => v2 migration guide #921

coilysiren · 2019-11-09T05:59:36Z

View the release notes for guidance on migrating => https://github.com/urfave/cli/releases/tag/v2.0.0

coilysiren · 2019-11-13T22:19:55Z

Here's a PR where @ffrank and @purpleidea make the v1 => v2 migration purpleidea/mgmt#571

coilysiren · 2019-11-13T22:35:39Z

Here's a quirky example of someone moving from the very very old v2 branch, to the latest v1 release sourcegraph/godockerize#10

☝️ I don't think that's the type of migration where's really looking to write documentation for? but it's interesting to look at

coilysiren · 2019-11-16T21:32:05Z

Here's another example migration PR google/cloud-print-connector#470

coilysiren · 2019-11-29T03:19:34Z

I'm going to work on this as a part of #952

coilysiren · 2019-11-29T08:41:20Z

In addition to working on this as a part of #952, I've been progressively updating the v2 release notes => https://github.com/urfave/cli/releases/tag/v2.0.0 to include fine grain migration instructions. I'll add more as I find them!

coilysiren · 2019-12-04T21:23:27Z

#952 was closed, so I no longer intend on working on this

coilysiren · 2019-12-06T18:44:15Z

+1 migration PR => technosophos/dashing#52

bonedaddy · 2020-01-04T07:08:42Z

command line flag migration steps also need to be updated, at the very least to document the way command-line flag aliases now behave.

Previously you could define aliases liek:

cli.StringFlag{
  Name: "config, cfg"
}

however you now need to do

cli.StringFlag{
    Name: "config",
    Aliases: []string{"cfg"},
}

Here is a minimal repro

package main

import (
	"fmt"
	"os"

	// auto register pprof handlers

	_ "net/http/pprof"

	au "github.com/logrusorgru/aurora"
	"github.com/urfave/cli/v2"
)

func main() {
	// generate the actual cli app
	app := newApp()
	// runthe cli app
	if err := app.Run(os.Args); err != nil {
		fmt.Printf(
			"%s %s\n",
			au.Bold(au.Red("error encountered:")),
			au.Red(err.Error()),
		)
		os.Exit(1)
	}
}

func newApp() *cli.App {
	app := cli.NewApp()
	app.Flags = loadFlags()
	return app
}

func loadFlags() []cli.Flag {
	return []cli.Flag{
		&cli.BoolFlag{
			Name:  "bootstrap, bp",
			Usage: "bootstrap against public ipfs",
		},
		&cli.StringFlag{
			Name:  "config, cfg",
			Usage: "load the configuration file at `PATH`",
			Value: "./config.yml",
		},
	}
}

coilysiren · 2020-01-04T08:19:26Z

@bonedaddy 👍 I added these lines

Removed the ability to specify multiple entries in the Command.Name field

when updating, replace Name: "a, b, c" with Name: "a", Aliases: []string{"b", "c"}

bonedaddy · 2020-01-04T08:59:35Z

@bonedaddy I added these lines

Removed the ability to specify multiple entries in the Command.Name field

when updating, replace Name: "a, b, c" with Name: "a", Aliases: []string{"b", "c"}

sweet, thank you 🚀

TomOnTime · 2020-02-03T16:21:32Z

I kept notes as I did a recent conversion. I think these are going to be the typical "first steps" for people (well... people like me!)

Import string changed

OLD: import "github.com/urfave/cli"
NEW: import "github.com/urfave/cli/v2"

Flag aliases are done differently.

Change Name: "foo, f to "Name: "foo", Aliases: []string{"f"}`

(Steal the examples in
#921 (comment)
...they are better)

Occurrences of []Command have been changed to []*Command

What this means to you:

a. Look for []cli.Command{} and change it to []*cli.Command{}

Example:

OLD: var commands = []cli.Command{}
NEW: var commands = []*cli.Command{}