cors

Documentation

Overview

cors package is net/http handler to handle CORS related requests as defined by http://www.w3.org/TR/cors/

You can configure it by passing an option struct to cors.New:

c := cors.New(cors.Options{
    AllowedOrigins: []string{"foo.com"},
    AllowedMethods: []string{"GET", "POST", "DELETE"},
    AllowCredentials: true,
})

Then insert the handler in the chain:

handler = c.Handler(handler)

See Options documentation for more options.

The resulting handler is a standard net/http handler.

Index

• func Handler(options Options) func(next http.Handler) http.Handler
• type Cors
  • func AllowAll() *Cors
  • func New(options Options) *Cors
  • func (c *Cors) Handler(next http.Handler) http.Handler
• type Logger
• type Options

Functions

func Handler

func Handler(options Options) func(next http.Handler) http.Handler

Handler creates a new Cors handler with passed options.

Types

type Cors

type Cors struct {
	// Debug logger
	Log Logger
	// contains filtered or unexported fields
}

Cors http handler

func AllowAll

func AllowAll() *Cors

AllowAll create a new Cors handler with permissive configuration allowing all origins with all standard methods with any header and credentials.

func New

func New(options Options) *Cors

New creates a new Cors handler with the provided options.

func (*Cors) Handler

func (c *Cors) Handler(next http.Handler) http.Handler

Handler apply the CORS specification on the request, and add relevant CORS headers as necessary.

type Logger

type Logger interface {
	Printf(string, ...interface{})
}

Logger generic interface for logger

type Options

type Options struct {
	// AllowedOrigins 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.
	// An origin may contain a wildcard (*) to replace 0 or more characters
	// (i.e.: http://*.domain.com). Usage of wildcards implies a small performance penalty.
	// Only one wildcard can be used per origin.
	// Default value is ["*"]
	AllowedOrigins []string

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

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

	// AllowedHeaders is list of non simple headers the client is allowed to use with
	// cross-domain requests.
	// If the special "*" value is present in the list, all headers will be allowed.
	// Default value is [] but "Origin" is always appended to the list.
	AllowedHeaders []string

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

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

	// AllowPrivateNetwork allows requests from private networks
	AllowPrivateNetwork bool

	// MaxAge indicates how long (in seconds) the results of a preflight request
	// can be cached
	MaxAge int

	// OptionsPassthrough instructs preflight to let other potential next handlers to
	// process the OPTIONS method. Turn this on if your application handles OPTIONS.
	OptionsPassthrough bool

	// Debugging flag adds additional output to debug server side CORS issues
	Debug bool
}

Options is a configuration container to setup the CORS middleware.