CORS
If you are having trouble authenticating with your application from an SPA that executes on a separate subdomain, you have likely misconfigured your CORS (Cross-Origin Resource Sharing) or session cookie settings.
You should ensure that your application's CORS configuration is returning the
Access-Control-Allow-Credentials header with a value of true by setting the AllowCredentials option within your cors middleware configuration to true.axios.defaults.withCredentials = true;
In this section you will learn how to use this middleware to allow cross-origin resource sharing.
1. Install the middleware:
$ go get github.com/iris-contrib/middleware/[email protected]
2. Import in your code:
import "github.com/iris-contrib/middleware/cors"
3. Initialize and configurate the middleware:
crs := cors.New(cors.Options{
AllowedOrigins: []string{"*"},
AllowCredentials: true,
})
4. Register the middleware:
app.UseRouter(crs)
That's all. Your Iris web server can now accept cross-origin API requests from your client.
Example of a raw Javascript Client:
// Replace the "host" with your Iris web server's domain.
const host = 'https://e1de7bc1.ngrok.io';
async function postData(url = '', data = {}) {
const response = await fetch(url, {
method: 'POST',
mode: 'cors',
cache: 'no-cache',
credentials: 'same-origin',
headers: {
'Content-Type': 'application/json'
},
redirect: 'follow',
referrerPolicy: 'no-referrer',
body: JSON.stringify(data)
});
return response.json();
}
postData(host + '/api/mailer', {
email: "[email protected]"
})
.then(data => {
console.log(data);
document.write(data.message);
});
The full configuration of the
cors.Options struct looks like this:// 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(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
// MaxAge indicates how long (in seconds) the results
// of a preflight request can be cached.
MaxAge int
// AllowCredentials indicates whether the request
// can include user credentials like
// cookies, HTTP authentication
// or client side SSL certificates.
AllowCredentials bool
// 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
You can always use the Iris request Context to manually send the necessary headers to handle preflight and therefore allow cross-origin requests.
Here is a simple example:
package main
import "github.com/kataras/iris/v12"
func main() {
app := iris.New()
// Our custom CORS middleware.
crs := func(ctx iris.Context) {
ctx.Header("Access-Control-Allow-Origin", "*")
ctx.Header("Access-Control-Allow-Credentials", "true")
if ctx.Method() == iris.MethodOptions {
ctx.Header("Access-Control-Methods",
"POST, PUT, PATCH, DELETE")
ctx.Header("Access-Control-Allow-Headers",
"Access-Control-Allow-Origin,Content-Type")
ctx.Header("Access-Control-Max-Age",
"86400")
ctx.StatusCode(iris.StatusNoContent)
return
}
ctx.Next()
}
app.UseRouter(crs)
// [register routes...]
}
Last modified 2yr ago