spf13--cobra/cobra

Cobra Generator

Cobra provides its own program that will create your application and add any commands you want. It's the easiest way to incorporate Cobra into your application.

In order to use the cobra command, compile it using the following command:

go get github.com/spf13/cobra/cobra

This will create the cobra executable under your $GOPATH/bin directory.

cobra init

The cobra init [app] command will create your initial application code for you. It is a very powerful application that will populate your program with the right structure so you can immediately enjoy all the benefits of Cobra. It will also automatically apply the license you specify to your application.

Cobra init is pretty smart. You can either run it in your current application directory or you can specify a relative path to an existing project. If the directory does not exist, it will be created for you.

Updates to the Cobra generator have now decoupled it from the GOPATH. As such --pkg-name is required.

Note: init will no longer fail on non-empty directories.

mkdir -p newApp && cd newApp
cobra init --pkg-name github.com/spf13/newApp

or

cobra init --pkg-name github.com/spf13/newApp path/to/newApp

cobra add

Once an application is initialized, Cobra can create additional commands for you. Let's say you created an app and you wanted the following commands for it:

• app serve
• app config
• app config create

In your project directory (where your main.go file is) you would run the following:

cobra add serve
cobra add config
cobra add create -p 'configCmd'

Note: Use camelCase (not snake_case/snake-case) for command names. Otherwise, you will encounter errors. For example, cobra add add-user is incorrect, but cobra add addUser is valid.

Once you have run these three commands you would have an app structure similar to the following:

  ▾ app/
    ▾ cmd/
        serve.go
        config.go
        create.go
      main.go

At this point you can run go run main.go and it would run your app. go run main.go serve, go run main.go config, go run main.go config create along with go run main.go help serve, etc. would all work.

Obviously you haven't added your own code to these yet. The commands are ready for you to give them their tasks. Have fun!

Configuring the cobra generator

The Cobra generator will be easier to use if you provide a simple configuration file which will help you eliminate providing a bunch of repeated information in flags over and over.

An example ~/.cobra.yaml file:

author: Steve Francia <spf@spf13.com>
license: MIT

You can also use built-in licenses. For example, GPLv2, GPLv3, LGPL, AGPL, MIT, 2-Clause BSD or 3-Clause BSD.

You can specify no license by setting license to none or you can specify a custom license:

author: Steve Francia <spf@spf13.com>
year: 2020
license:
  header: This file is part of CLI application foo.
  text: |
    {{ .copyright }}

    This is my license. There are many like it, but this one is mine.
    My license is my best friend. It is my life. I must master it as I must
    master my life.    

In the above custom license configuration the copyright line in the License text is generated from the author and year properties. The content of the LICENSE file is

Copyright © 2020 Steve Francia <spf@spf13.com>

This is my license. There are many like it, but this one is mine.
My license is my best friend. It is my life. I must master it as I must
master my life.

The header property is used as the license header files. No interpolation is done. This is the example of the go file header.

/*
Copyright © 2020 Steve Francia <spf@spf13.com>
This file is part of CLI application foo.
*/