Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/spf13/cobra-cli

Cobra CLI tool to generate applications and commands
https://github.com/spf13/cobra-cli

Last synced: 2 days ago
JSON representation

Cobra CLI tool to generate applications and commands

Awesome Lists containing this project

README 

        
# 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.



Install the cobra generator with the command `go install github.com/spf13/cobra-cli@latest`. 

Go will automatically install it in your `$GOPATH/bin` directory which should be in your $PATH. 



Once installed you should have the `cobra-cli` command available. Confirm by typing `cobra-cli` at a 

command line. 



There are only two operations currently supported by the Cobra generator: 



### cobra-cli init



The `cobra-cli 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 can also apply the license you specify to your application.



With the introduction of Go modules, the Cobra generator has been simplified to

take advantage of modules. The Cobra generator works from within a Go module. 



#### Initalizing a module



__If you already have a module, skip this step.__



If you want to initialize a new Go module: 



 1. Create a new directory 

 2. `cd` into that directory

 3. run `go mod init `



e.g. 

```

cd $HOME/code 

mkdir myapp

cd myapp

go mod init github.com/spf13/myapp

```



#### Initalizing a Cobra CLI application



From within a Go module run `cobra-cli init`. This will create a new barebones project

for you to edit. 



You should be able to run your new application immediately. Try it with 

`go run main.go`. 



You will want to open up and edit 'cmd/root.go' and provide your own description and logic. 



e.g.

```

cd $HOME/code/myapp

cobra-cli init

go run main.go

```



cobra-cli init can also be run from a subdirectory such as how the [cobra generator itself is organized](https://github.com/spf13/cobra-cli).

This is useful if you want to keep your application code separate from your library code.



#### Optional flags:

You can provide it your author name with the `--author` flag. 

e.g. `cobra-cli init --author "Steve Francia [email protected]"`



You can provide a license to use with `--license` 

e.g. `cobra-cli init --license apache`



Use the `--viper` flag to automatically setup [viper](https://github.com/spf13/viper)



Viper is a companion to Cobra intended to provide easy handling of environment variables and config files and seamlessly connecting them to the application flags.



### Add commands to a project



Once a cobra application is initialized you can continue to use the Cobra generator to 

add additional commands to your application. The command to do this is `cobra-cli add`. 



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-cli add serve

cobra-cli add config

cobra-cli add create -p 'configCmd'

```



`cobra-cli add` supports all the same optional flags as `cobra-cli init` does (described above).



You'll notice that this final command has a `-p` flag. This is used to assign a

parent command to the newly added command. In this case, we want to assign the

"create" command to the "config" command. All commands have a default parent of rootCmd if not specified.  



By default `cobra-cli` will append `Cmd` to the name provided and uses this name for the internal variable name. When specifying a parent, be sure to match the variable name used in the code. 



*Note: Use camelCase (not snake_case/kebab-case) for command names.

Otherwise, you will encounter errors.

For example, `cobra-cli add add-user` is incorrect, but `cobra-cli add addUser` is valid.*



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

the following:



```

  ▾ app/

    ▾ cmd/

        config.go

        create.go

        serve.go

        root.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.



You now have a basic Cobra-based application up and running. Next step is to edit the files in cmd and customize them for your application.



For complete details on using the Cobra library, please read the [The Cobra User Guide](https://github.com/spf13/cobra/blob/main/site/content/user_guide.md#using-the-cobra-library).



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:



```yaml

author: Steve Francia 

license: MIT

useViper: true

```



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:



```yaml

author: Steve Francia 

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 



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 

This file is part of CLI application foo.

*/

```