405 Method Not Allowed error on Amazon s3 contact form bucket

1

I am attempting to get an contact form working on an Amazon s3 bucket. I can receive email when running tests via Lambda and API Gateway just fine but when I try to submit the form via the website I get a 405 Method not allowed error:

405 Method Not Allowed

  • Code: MethodNotAllowed
  • Message: The specified method is not allowed against this resource.
  • Method: POST
  • ResourceType: OBJECT

I am at a loss of what to even look for at this point. I was having other issues with the API Gateway giving me a 500 error until I turned off the proxy option. Now the API gateway works but the contact form is still giving me this error.

The form is as follows.

<form method="post" role="form">
        <p>Name</p>
        <div class="">
            <label for="contact-name" class="" requiured></label>
            <input type="text" class="form-input" id="contact-name">
        </div>
        <p>E-mail</p>
        <div class="">
            <label for="contact-email" class="" requiured></label>
            <input type="email" class="form-input" id="contact-email" aria-describedby="emailHelp1">
        </div>
        <p>Message</p>
        <div class="">
            <label for="contact-message" class="form-label"></label>
            <textarea class="form-input" id="contact-message" rows="3"></textarea>
        </div>
        <button type="submit" onClick=submitToAPI(event) class="btn btn-primary">Submit</button>
    </form>

The below code made no additional change to the error, I found it in a tutorial and modified it for my needs.

function submitToAPI(e) {
    e.preventDefault();
    var URL = "...API URL";

         var Namere = /[A-Za-z]{1}[A-Za-z]/;
         if (!Namere.test($("#contact-name").val())) {
                      alert ("Name can not less than 2 char");
             return;
         }
         
         if ($("#contact-email").val()=="") {
             alert ("Please enter your email id");
             return;
         }

         var reeamil = /^([\w-\.]+@([\w-]+\.)+[\w-]{2,6})?$/;
         if (!reeamil.test($("#contact-email").val())) {
             alert ("Please enter valid email address");
             return;
         }

    var name = $("#contact-name").val();
    
    var email = $("#contact-email").val();
    var desc = $("#contact-message").val();
    var data = {
       name : name,
       
       email : email,
       message : desc
     };

    $.ajax({
      type: "POST",
      url : URL,
      dataType: "json",
      crossDomain: "true",
      contentType: "application/json; charset=utf-8",
      data: JSON.stringify(data),

      
      success: function () {
        // clear form and show a success message
        alert("Successfull");
        document.getElementById("contact-form").reset();
    location.reload();
      },
      error: function () {
        // show an error message
        alert("UnSuccessfull");
      }});
  }

If I were to run this on a normal server I would have an action listed to some php code, but that's not how this works in this case as I am making a POST call to a gateway. If I add the invoke url as an action I get the same error and the examples I've seen online do not use the action tag to invoke the api gateway

1 Answer
0

Greeting

Hi CodingYost!

Thank you for sharing the details of your issue. Let’s dive in and resolve the 405 Method Not Allowed error you're encountering with your contact form hosted on Amazon S3.


Clarifying the Issue

From your description, you're hosting a contact form on an Amazon S3 bucket and relying on Lambda and API Gateway for processing submissions. While Lambda and API Gateway tests work as expected, submitting the form via your website triggers a 405 Method Not Allowed error. You’ve also adjusted the API Gateway proxy settings, which fixed a 500 error but did not resolve this issue.

This error happens because S3 is a static host and doesn’t handle server-side operations or POST requests. API Gateway must be configured to handle the POST request and ensure compatibility with the browser through proper CORS settings and permissions.


Key Terms

  • 405 Method Not Allowed: Indicates that the request method (e.g., POST) is not supported by the target resource.
  • Amazon S3: A static web hosting service without support for server-side logic or methods like POST.
  • Amazon API Gateway: A service for routing HTTP methods (like POST) to backend resources such as Lambda functions.
  • CORS (Cross-Origin Resource Sharing): A security mechanism that controls access between different origins (e.g., your S3-hosted website and API Gateway).
  • Preflight Request: An initial HTTP OPTIONS request sent by the browser to determine if the actual request is safe to send.

The Solution (Our Recipe)

Steps at a Glance:

  1. Confirm the API Gateway endpoint supports CORS with proper headers.
  2. Verify the API Gateway POST method is mapped correctly to your Lambda function.
  3. Update your form’s JavaScript logic with the correct API Gateway URL, headers, and error handling.
  4. Ensure the API Gateway execution role has sufficient permissions for Lambda invocation.
  5. Debug with CloudWatch logs and browser developer tools to identify any lingering issues.
  6. Test the form submission and fine-tune configurations for edge cases, such as preflight requests or custom headers.

Step-by-Step Guide:

  1. Enable CORS on API Gateway:
    • Navigate to your API in the API Gateway console, select the POST method, and enable CORS by specifying the following headers:
      • Access-Control-Allow-Origin: Use your S3 bucket URL (e.g., https://your-bucket-name.s3.amazonaws.com) or * for testing.
      • Access-Control-Allow-Methods: Include POST.
      • Access-Control-Allow-Headers: Add Content-Type, x-api-key, and any other custom headers your API requires.
    • After enabling CORS, redeploy your API stage.

  1. Verify POST Method Mapping:
    • Ensure the POST method is integrated with your Lambda function in the Method Integration settings.
    • Check that the HTTP method is set to POST in both the request and integration settings.

  1. Update JavaScript Logic:
    Here's an enhanced version of your submitToAPI function with advanced error handling:

    function submitToAPI(e) {
        e.preventDefault();
        var URL = "https://your-api-id.execute-api.region.amazonaws.com/stage-name";
    
        var data = {
            name: $("#contact-name").val(),
            email: $("#contact-email").val(),
            message: $("#contact-message").val()
        };
    
        $.ajax({
            type: "POST",
            url: URL,
            dataType: "json",
            contentType: "application/json; charset=utf-8",
            data: JSON.stringify(data),
            success: function () {
                alert("Form submitted successfully!");
                document.getElementById("contact-form").reset();
            },
            error: function (xhr, status, error) {
                console.error("Error:", error);
                console.error("Response:", xhr.responseText);
    
                if (xhr.status === 405) {
                    alert("Error: Method not allowed. Check API Gateway configuration.");
                } else if (xhr.status === 403) {
                    alert("Error: Forbidden. Check API permissions.");
                } else if (xhr.status === 0) {
                    alert("Network error. Verify your API Gateway URL.");
                } else {
                    alert("Form submission failed. Please try again.");
                }
            }
        });
    }

  1. Check IAM Roles and Permissions:
    • Ensure the API Gateway execution role has lambda:InvokeFunction permissions for the Lambda function.
    • Check your Lambda function's resource-based policy (if any) to confirm API Gateway is authorized to invoke it.

  1. Debug with Logs and Tools:
    • API Gateway Logs: Enable execution logging in API Gateway to monitor the POST method. Look for misconfigurations or errors in the logs.
    • Browser Developer Tools: Use the "Network" tab to inspect the POST request and preflight (OPTIONS) request. Ensure the responses include the required CORS headers.
    • Postman or curl: Test the API Gateway endpoint using tools like Postman or curl to validate the backend independently of your website’s configuration.

  1. Test and Address Edge Cases:
    • If you use custom headers (e.g., x-api-key), ensure they are included in the CORS Access-Control-Allow-Headers setting.
    • For production, restrict Access-Control-Allow-Origin to your S3 bucket URL instead of using a wildcard (*).
    • Address rate limiting (429 errors) by configuring throttling settings in API Gateway if necessary.

Closing Thoughts

This refined solution adds advanced debugging and error-handling tools, giving you a comprehensive way to resolve the 405 Method Not Allowed error while future-proofing your API Gateway configuration. Using tools like Postman or curl can also help validate your API without the browser’s CORS constraints. Let me know if you need help with any of these steps!


Farewell

Best of luck with your project, CodingYost! I’m confident you’ll have this running smoothly soon. If you encounter more challenges, don’t hesitate to reach out! 🚀✨


Cheers,

Aaron 😊

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answered 2 months ago

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