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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-echo

CORS options#

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

Quick start#

1.Create boot.yaml#

---
echo:
  - 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#

package main

import (
  "context"
  "fmt"
  "github.com/labstack/echo/v4"
  "github.com/rookie-ninja/rk-boot/v2"
  "github.com/rookie-ninja/rk-echo/boot"
  "net/http"
)

func main() {
  // Create a new boot instance.
  boot := rkboot.NewBoot()

  // Register handler
  echoEntry := rkecho.GetEchoEntry("greeter")
  echoEntry.Echo.GET("/v1/greeter", Greeter)

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

  boot.WaitForShutdownSig(context.TODO())
}

func Greeter(ctx echo.Context) error {
  return ctx.JSON(http.StatusOK, &GreeterResponse{
    Message: fmt.Sprintf("Hello %s!", ctx.QueryParam("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 echo.middleware.cors.allowOrigins to http://localhost:8080

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

Cheers#