fukuoka.go #8

1. How to build and
distribute CLI tool in15
Minutes with Golang
@kohei_kimura

2. Today’s topic:
CLI tool with Golang

3. Main Targets
• Beginners
• want to build something with Golang.
• have not used Golang since A Tour of Go.

4. • I’m not a beginner!
• I’d like to hear stories about parallel
processing!
Sorry, please install and try stopho, my CLI tool:
or
go get -d github.com/kohei-kimura/stopho
brew tap kohei-kimura/homebrew-stopho
brew install stopho

5. stopho →
CLI tool to generate search URLs from stock
photos web sites

6. Why CLI tools with Golang?

7. Why CLI tools with Golang?
A lot of library for CLI tools
Cross compile
Not have to write CSS!

8. Building CLI tools is
tiresome?
• sub commands
• options
• arguments
• helps …

9. Humanity has urfave/cli
Package for building command line apps
https://github.com/urfave/cli

10. app.Commands = []cli.Command{
{
Name: "search", // Sub command: `stopho search`
ShortName: "s", // Alias: `stopho s`
Usage: "Generate search URLs from stock photos web sites",
Action: command.CmdSearch,
Flags: []cli.Flag{ // Options
cli.BoolFlag{ // TRUE or FALSE
Name: "japan, j", // `stopho s --japan` or `stopho s -j`
Usage: "Enable Japan mode",
},
cli.StringFlag{ // `stopho s -s $SITE_NAME`
Name: "site, s",
Usage: "Display only sites matched `value`",
},
},
},
}

11. func CmdSearch(c *cli.Context) {
// Arguments
term := c.Args().Get(0)
// Bool Options
if c.Bool("japan") {
// japan mode
}
// String Options
fmt.Println(c.String("site"))
}
Function

12. // Set Writer
outStream = new(bytes.Buffer)
app.Writer = outStream
~~~~~~
// Use `fmt.Fprintf`
fmt.Fprintf(c.App.Writer, ...)
Testing

13. tcnksm/gcli
• generate CLI skeleton
• urfave/cli and other CLI frameworks

14. Distribution

15. Compile by `gox`
• done!
• easy!
go get github.com/mitchellh/gox
gox

16. GitHub Releases
1. `Releases` tab in repository page
2. `Create a new release` button
3. Upload binary files
4. done!

17. Homebew
• ruby script for building apps
• https://github.com/Homebrew/brew/blob/
master/docs/Formula-Cookbook.md
$ brew create --set-name $APP_NAME $URL
# edit your `$APPNAME.rb`!
$ git push

18. Summary
Framework: urfave/cli
Generator: tcnksm/gcli
Compile tool: mitchellh/gox
Release platform: GitHub Releases

19. Tips
Build a simple and small tool!
Refer to famous tools! - e.g. git, docker, …
Provide aliases of subcommands and options!
Add GIF animation in README.md
Promote on reddit and twitter

21. @kohei_kimura
Ɠ IDC Frontier Inc.
Developing IoT Platform
Back-end on the activity recognition project
@kohei_kimura
kohei-kimura
kohei-kimura.github.io
♥ Visual Studio Code
Kitakyushu -> Yokohama -> Fukuoka

22. IDCF Cloud - One coin IaaS

23. Enjoy your Go programming!
Please star my Stopho! ->
Please follow me! ->