Files
fn-serverless/vendor/github.com/gin-contrib/cors/config.go
Alexander Bransby-Sharples c5ec0cc41e Add CORS support to fn api (#455)
The Gin middleware is being used if one or more Origins are specified. Default setup for each Origin is as follows:

- GET,POST, PUT, HEAD methods allowed
- Credentials share disabled
- Preflight requests cached for 12 hours

Which are the defaults gin-contrib/cors comes with out of the box.

Gin-cors will return a 403 if it gets a request with an Origin header that isn't on its' list. If no Origin header is specified then it will just return the servers response.

Start fn with CORS enabled:

`API_CORS="http://localhost:4000, http://localhost:3000" make run`
2017-11-16 15:37:26 +00:00

84 lines
1.7 KiB
Go

package cors
import (
"net/http"
"github.com/gin-gonic/gin"
)
type cors struct {
allowAllOrigins bool
allowCredentials bool
allowOriginFunc func(string) bool
allowOrigins []string
exposeHeaders []string
normalHeaders http.Header
preflightHeaders http.Header
}
func newCors(config Config) *cors {
if err := config.Validate(); err != nil {
panic(err.Error())
}
return &cors{
allowOriginFunc: config.AllowOriginFunc,
allowAllOrigins: config.AllowAllOrigins,
allowCredentials: config.AllowCredentials,
allowOrigins: normalize(config.AllowOrigins),
normalHeaders: generateNormalHeaders(config),
preflightHeaders: generatePreflightHeaders(config),
}
}
func (cors *cors) applyCors(c *gin.Context) {
origin := c.Request.Header.Get("Origin")
if len(origin) == 0 {
// request is not a CORS request
return
}
if !cors.validateOrigin(origin) {
c.AbortWithStatus(http.StatusForbidden)
return
}
if c.Request.Method == "OPTIONS" {
cors.handlePreflight(c)
defer c.AbortWithStatus(200)
} else {
cors.handleNormal(c)
}
if !cors.allowAllOrigins {
c.Header("Access-Control-Allow-Origin", origin)
}
}
func (cors *cors) validateOrigin(origin string) bool {
if cors.allowAllOrigins {
return true
}
for _, value := range cors.allowOrigins {
if value == origin {
return true
}
}
if cors.allowOriginFunc != nil {
return cors.allowOriginFunc(origin)
}
return false
}
func (cors *cors) handlePreflight(c *gin.Context) {
header := c.Writer.Header()
for key, value := range cors.preflightHeaders {
header[key] = value
}
}
func (cors *cors) handleNormal(c *gin.Context) {
header := c.Writer.Header()
for key, value := range cors.normalHeaders {
header[key] = value
}
}