cors

README

CORS gin's middleware

Gin middleware/handler to enable CORS support.

Usage

Start using it

Download and install it:

go get github.com/gin-contrib/cors

Import it in your code:

import "github.com/gin-contrib/cors"

Canonical example

package main

import (
  "time"

  "github.com/gin-contrib/cors"
  "github.com/gin-gonic/gin"
)

func main() {
  router := gin.Default()
  // CORS for https://foo.com and https://github.com origins, allowing:
  // - PUT and PATCH methods
  // - Origin header
  // - Credentials share
  // - Preflight requests cached for 12 hours
  router.Use(cors.New(cors.Config{
    AllowOrigins:     []string{"https://foo.com"},
    AllowMethods:     []string{"PUT", "PATCH"},
    AllowHeaders:     []string{"Origin"},
    ExposeHeaders:    []string{"Content-Length"},
    AllowCredentials: true,
    AllowOriginFunc: func(origin string) bool {
      return origin == "https://github.com"
    },
    MaxAge: 12 * time.Hour,
  }))
  router.Run()
}

Using DefaultConfig as start point

func main() {
  router := gin.Default()
  // - No origin allowed by default
  // - GET,POST, PUT, HEAD methods
  // - Credentials share disabled
  // - Preflight requests cached for 12 hours
  config := cors.DefaultConfig()
  config.AllowOrigins = []string{"http://google.com"}
  // config.AllowOrigins = []string{"http://google.com", "http://facebook.com"}
  // config.AllowAllOrigins = true

  router.Use(cors.New(config))
  router.Run()
}

Note: while Default() allows all origins, DefaultConfig() does not and you will still have to use AllowAllOrigins.

Default() allows all origins

func main() {
  router := gin.Default()
  // same as
  // config := cors.DefaultConfig()
  // config.AllowAllOrigins = true
  // router.Use(cors.New(config))
  router.Use(cors.Default())
  router.Run()
}

Using all origins disables the ability for Gin to set cookies for clients. When dealing with credentials, don't allow all origins.

Documentation

Index

• Variables
• func Default() gin.HandlerFunc
• func New(config Config) gin.HandlerFunc
• type Config
  • func DefaultConfig() Config
  • func (c *Config) AddAllowHeaders(headers ...string)
  • func (c *Config) AddAllowMethods(methods ...string)
  • func (c *Config) AddExposeHeaders(headers ...string)
  • func (c Config) Validate() error

Variables

var (
	DefaultSchemas = []string{
		"http://",
		"https://",
	}
	ExtensionSchemas = []string{
		"chrome-extension://",
		"safari-extension://",
		"moz-extension://",
		"ms-browser-extension://",
	}
	FileSchemas = []string{
		"file://",
	}
	WebSocketSchemas = []string{
		"ws://",
		"wss://",
	}
)

Functions

func Default

func Default() gin.HandlerFunc

Default returns the location middleware with default configuration.

func New

func New(config Config) gin.HandlerFunc

New returns the location middleware with user-defined custom configuration.

Types

type Config

type Config struct {
	AllowAllOrigins bool

	// AllowOrigins is a list of origins a cross-domain request can be executed from.
	// If the special "*" value is present in the list, all origins will be allowed.
	// Default value is []
	AllowOrigins []string

	// AllowOriginFunc is a custom function to validate the origin. It takes the origin
	// as an argument and returns true if allowed or false otherwise. If this option is
	// set, the content of AllowOrigins is ignored.
	AllowOriginFunc func(origin string) bool

	// AllowMethods is a list of methods the client is allowed to use with
	// cross-domain requests. Default value is simple methods (GET, POST, PUT, PATCH, DELETE, HEAD, and OPTIONS)
	AllowMethods []string

	// AllowPrivateNetwork indicates whether the response should include allow private network header
	AllowPrivateNetwork bool

	// AllowHeaders is list of non simple headers the client is allowed to use with
	// cross-domain requests.
	AllowHeaders []string

	// AllowCredentials indicates whether the request can include user credentials like
	// cookies, HTTP authentication or client side SSL certificates.
	AllowCredentials bool

	// ExposeHeaders indicates which headers are safe to expose to the API of a CORS
	// API specification
	ExposeHeaders []string

	// MaxAge indicates how long (with second-precision) the results of a preflight request
	// can be cached
	MaxAge time.Duration

	// Allows to add origins like http://some-domain/*, https://api.* or http://some.*.subdomain.com
	AllowWildcard bool

	// Allows usage of popular browser extensions schemas
	AllowBrowserExtensions bool

	// Allows usage of WebSocket protocol
	AllowWebSockets bool

	// Allows usage of file:// schema (dangerous!) use it only when you 100% sure it's needed
	AllowFiles bool

	// Allows to pass custom OPTIONS response status code for old browsers / clients
	OptionsResponseStatusCode int
}

Config represents all available options for the middleware.

func DefaultConfig

func DefaultConfig() Config

DefaultConfig returns a generic default configuration mapped to localhost.

func (*Config) AddAllowHeaders

func (c *Config) AddAllowHeaders(headers ...string)

AddAllowHeaders is allowed to add custom headers

func (*Config) AddAllowMethods

func (c *Config) AddAllowMethods(methods ...string)

AddAllowMethods is allowed to add custom methods

func (*Config) AddExposeHeaders

func (c *Config) AddExposeHeaders(headers ...string)

AddExposeHeaders is allowed to add custom expose headers

func (Config) Validate

func (c Config) Validate() error

Validate is check configuration of user defined.