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CORS

Enable CORS middleware

Install#

go get github.com/rookie-ninja/rk-boot/v2
go get github.com/rookie-ninja/rk-mux

CORS options#

options description type default
mux.middleware.cors.enabled Enable CORS middleware boolean false
mux.middleware.cors.ignore Ignore by path []string []
mux.middleware.cors.allowOrigins Allowed origin list []string *
mux.middleware.cors.allowMethods Allowed http method list []string All http methods
mux.middleware.cors.allowHeaders Allowed http header list []string Headers from request
mux.middleware.cors.allowCredentials Allowed credential list bool false
mux.middleware.cors.exposeHeaders Exposed list of headers []string ""
mux.middleware.cors.maxAge Max age int 0

Quick start#

1.Create boot.yaml#

---
mux:
  - name: greeter
    port: 8080
    enabled: true
    middleware:
      cors:
        enabled: true
        allowOrigins:
          - "http://localhost:*"
#        ignore: [""]
#        allowCredentials: false
#        allowHeaders: []
#        allowMethods: []
#        exposeHeaders: []
#        maxAge: 0

2.Create main.go#

// Copyright (c) 2021 rookie-ninja
//
// Use of this source code is governed by an Apache-style
// license that can be found in the LICENSE file.
package main

import (
  "context"
  _ "embed"
  "fmt"
  "github.com/rookie-ninja/rk-boot/v2"
  "github.com/rookie-ninja/rk-mux/boot"
  "github.com/rookie-ninja/rk-mux/middleware"
  "net/http"
)

// @title RK Swagger for Mux
// @version 1.0
// @description This is a greeter service with rk-boot.
func main() {
  // Create a new boot instance.
  boot := rkboot.NewBoot()

  // Get MuxEntry
  muxEntry := rkmux.GetMuxEntry("greeter")
  // Use *mux.Router adding handler.
  muxEntry.Router.NewRoute().Path("/v1/greeter").HandlerFunc(Greeter)

  // Bootstrap
  boot.Bootstrap(context.TODO())

  boot.WaitForShutdownSig(context.TODO())
}

// Greeter handler
// @Summary Greeter service
// @Id 1
// @version 1.0
// @produce application/json
// @Param name query string true "Input name"
// @Success 200 {object} GreeterResponse
// @Router /v1/greeter [get]
func Greeter(writer http.ResponseWriter, req *http.Request) {
  rkmuxmid.WriteJson(writer, http.StatusOK, &GreeterResponse{
    Message: fmt.Sprintf("Hello %s!", req.URL.Query().Get("name")),
  })
}

type GreeterResponse struct {
  Message string
}

3.Create cors.html#

<!DOCTYPE html>
<html>
<body>

<h1>CORS Test</h1>

<p>Call http://localhost:8080/v1/greeter</p>

<script type="text/javascript">
    window.onload = function() {
        var apiUrl = 'http://localhost:8080/v1/greeter';
        fetch(apiUrl).then(response => response.json()).then(data => {
            document.getElementById("res").innerHTML = data["Message"]
        }).catch(err => {
            document.getElementById("res").innerHTML = err
        });
    };
</script>

<h4>Response: </h4>
<p id="res"></p>

</body>
</html>

4.Directory hierarchy#

.
├── boot.yaml
├── cors.html
├── go.mod
├── go.sum
└── main.go

0 directories, 5 files

5.Validate#

Open cors.html

6.Blocked CORS#

Set mux.middleware.cors.allowOrigins to http://localhost:8080

---
mux:
  - name: greeter
    port: 8080
    enabled: true
    middleware:
      cors:
        enabled: true
        allowOrigins:
          - "http://localhost:8080"

Cheers#