mirror of
https://github.com/ceph/ceph-csi.git
synced 2024-12-20 20:10:22 +00:00
9c8de9471e
update kubernetes and its dependencies to v1.26.1 Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>
113 lines
4.3 KiB
Markdown
113 lines
4.3 KiB
Markdown
|
|
|
|
Cobra is a library for creating powerful modern CLI applications.
|
|
|
|
Cobra is used in many Go projects such as [Kubernetes](https://kubernetes.io/),
|
|
[Hugo](https://gohugo.io), and [GitHub CLI](https://github.com/cli/cli) to
|
|
name a few. [This list](./projects_using_cobra.md) contains a more extensive list of projects using Cobra.
|
|
|
|
[](https://github.com/spf13/cobra/actions?query=workflow%3ATest)
|
|
[](https://pkg.go.dev/github.com/spf13/cobra)
|
|
[](https://goreportcard.com/report/github.com/spf13/cobra)
|
|
[](https://gophers.slack.com/archives/CD3LP1199)
|
|
|
|
# Overview
|
|
|
|
Cobra is a library providing a simple interface to create powerful modern CLI
|
|
interfaces similar to git & go tools.
|
|
|
|
Cobra provides:
|
|
* Easy subcommand-based CLIs: `app server`, `app fetch`, etc.
|
|
* Fully POSIX-compliant flags (including short & long versions)
|
|
* Nested subcommands
|
|
* Global, local and cascading flags
|
|
* Intelligent suggestions (`app srver`... did you mean `app server`?)
|
|
* Automatic help generation for commands and flags
|
|
* Grouping help for subcommands
|
|
* Automatic help flag recognition of `-h`, `--help`, etc.
|
|
* Automatically generated shell autocomplete for your application (bash, zsh, fish, powershell)
|
|
* Automatically generated man pages for your application
|
|
* Command aliases so you can change things without breaking them
|
|
* The flexibility to define your own help, usage, etc.
|
|
* Optional seamless integration with [viper](https://github.com/spf13/viper) for 12-factor apps
|
|
|
|
# Concepts
|
|
|
|
Cobra is built on a structure of commands, arguments & flags.
|
|
|
|
**Commands** represent actions, **Args** are things and **Flags** are modifiers for those actions.
|
|
|
|
The best applications read like sentences when used, and as a result, users
|
|
intuitively know how to interact with them.
|
|
|
|
The pattern to follow is
|
|
`APPNAME VERB NOUN --ADJECTIVE`
|
|
or
|
|
`APPNAME COMMAND ARG --FLAG`.
|
|
|
|
A few good real world examples may better illustrate this point.
|
|
|
|
In the following example, 'server' is a command, and 'port' is a flag:
|
|
|
|
hugo server --port=1313
|
|
|
|
In this command we are telling Git to clone the url bare.
|
|
|
|
git clone URL --bare
|
|
|
|
## Commands
|
|
|
|
Command is the central point of the application. Each interaction that
|
|
the application supports will be contained in a Command. A command can
|
|
have children commands and optionally run an action.
|
|
|
|
In the example above, 'server' is the command.
|
|
|
|
[More about cobra.Command](https://pkg.go.dev/github.com/spf13/cobra#Command)
|
|
|
|
## Flags
|
|
|
|
A flag is a way to modify the behavior of a command. Cobra supports
|
|
fully POSIX-compliant flags as well as the Go [flag package](https://golang.org/pkg/flag/).
|
|
A Cobra command can define flags that persist through to children commands
|
|
and flags that are only available to that command.
|
|
|
|
In the example above, 'port' is the flag.
|
|
|
|
Flag functionality is provided by the [pflag
|
|
library](https://github.com/spf13/pflag), a fork of the flag standard library
|
|
which maintains the same interface while adding POSIX compliance.
|
|
|
|
# Installing
|
|
Using Cobra is easy. First, use `go get` to install the latest version
|
|
of the library.
|
|
|
|
```
|
|
go get -u github.com/spf13/cobra@latest
|
|
```
|
|
|
|
Next, include Cobra in your application:
|
|
|
|
```go
|
|
import "github.com/spf13/cobra"
|
|
```
|
|
|
|
# Usage
|
|
`cobra-cli` is a command line program to generate cobra applications and command files.
|
|
It will bootstrap your application scaffolding to rapidly
|
|
develop a Cobra-based application. It is the easiest way to incorporate Cobra into your application.
|
|
|
|
It can be installed by running:
|
|
|
|
```
|
|
go install github.com/spf13/cobra-cli@latest
|
|
```
|
|
|
|
For complete details on using the Cobra-CLI generator, please read [The Cobra Generator README](https://github.com/spf13/cobra-cli/blob/main/README.md)
|
|
|
|
For complete details on using the Cobra library, please read the [The Cobra User Guide](user_guide.md).
|
|
|
|
# License
|
|
|
|
Cobra is released under the Apache 2.0 license. See [LICENSE.txt](https://github.com/spf13/cobra/blob/master/LICENSE.txt)
|