Configure an HTTP trigger

Procedure

1. Log on to the Function Compute console.
2. In the left-side navigation pane, click Services and Functions.
3. In the top navigation bar, select the region where the service resides.
4. On the Services page, find the service that you want to manage and click Functions in the Actions column.
5. On the Functions page, click Create Function.
6. On the Create Function page, select Create from scratch. In the Basic Settings section, enter the function information and click Create.
   

   Parameter	Configuration method	Example
   Parameter	The name of the function.	http-function
   Runtime environment	Select a language that is familiar to you, such as Python, Java, PHP, or Node.js.	Python3
   Function trigger mode	Select Triggered by Event or Triggered by HTTP Request.	Triggered by HTTP request
   Instance architecture	Select Elastic Instance or Performance Instance.	Elastic instance
   Memory specification	The memory that is required to execute the function. Valid values: Select Elastic Instance. The memory specifications can be 128 MB, 256 MB, 512 MB, 1 GB, 2 GB, or 3 GB. Select Performance Instance. The memory specification can be 4 GB, 8 GB, 16 GB, or 32 GB.	512 MB

   After the function is created, a default HTTP trigger is automatically created. Click the target function, and then click the Triggers tab. You can view the HTTP triggers created by default.

Write code for a function

After you create an HTTP trigger, you can start writing function code.

var getRawBody = require('raw-body')
module.exports.handler = function (request, response, context) {
    // get request info
    getRawBody(request, function (err, data) {
        var params = {
            path: request.path,
            queries: request.queries,
            headers: request.headers,
            method: request.method,
            body: data,
            url: request.url,
            clientIP: request.clientIP,
        }
        // you can deal with your own logic here
        // set response
        var respBody = new Buffer.from(JSON.stringify(params));
        // var respBody = new Buffer( )
        response.setStatusCode(200)
        response.setHeader('content-type', 'application/json')
        response.send(respBody)
    })
};

# -*- coding: utf-8 -*-
import json
HELLO_WORLD = b"Hello world!\n"
def handler(environ, start_response):
    request_uri = environ['fc.request_uri']
    response_body = {
      'uri':environ['fc.request_uri'],
      'method':environ['REQUEST_METHOD']
    }
    # do something here
    status = '200 OK'
    response_headers = [('Content-type', 'text/json')]
    start_response(status, response_headers)
    # Python2
    return [json.dumps(response_body)]
    # Python3 tips: When using Python3, the str and bytes types cannot be mixed.
    # Use str.encode() to go from str to bytes
    # return [json.dumps(response_body).encode()]

<?php
use RingCentral\Psr7\Response;
function handler($request, $context): Response{
    /*
    $body       = $request->getBody()->getContents();
    $queries    = $request->getQueryParams();
    $method     = $request->getMethod();
    $headers    = $request->getHeaders();
    $path       = $request->getAttribute("path");
    $requestURI = $request->getAttribute("requestURI");
    $clientIP   = $request->getAttribute("clientIP");
    */
    return new Response(
        200,
        array(
            "custom_header1" => "v1",
            "custom_header2" => ["v2", "v3"],
        ),
        "hello world"
    );
}

Debug a function

You can use the Function Compute console or a browser to send HTTP requests to test whether the function is correct.

On the function details page, click the Function Code tab, and then click Test Function.

After the execution is complete, you can view the message that appears on the Function Code tab.

1. Assemble the HTTP trigger URL.
   The assembly rules of the HTTP trigger URL are as follows:

   <account_id>.<region>.fc.aliyuncs.com/<version>/proxy/<serviceName>/<functionName>/[action?queries]            

   Example:

   123456.cn-shanghai.fc.aliyuncs.com/2016-08-15/proxy/serviceName/functionName/action?hello=world           

   The parameters in URL are described as follows:

   Parameter	Description
   account_id	The ID of your Alibaba Cloud account. You can retrieve your account ID in Security Settings If you are a RAM user, move the pointer over the avatar in the upper-right corner of the console to view your Alibaba Cloud account ID.
   region	The region where the Function Compute instance is located.
   version	The API version of Function Compute.
   serviceName	The name of the service.
   functionName	The name of the function.
   action	The custom request path.
   queries	The query parameter.

2. In the address bar of your browser, enter the HTTP trigger URL and press Enter.
   The browser returns the execution result.

FAQ

Why is the HTTP function unable to be executed?

• If a new trigger is created, updating the cache for the trigger takes about 10 seconds. You can try again later.
• Check whether the handler function specified for your function is correct. An HTTP function uses a different handler function than that of a common function. For more information about HTTP functions in different languages, see the following documentation:
  • Node.js HTTP functions
  • Python HTTP functions
  • PHP HTTP functions
  • Java HTTP functions
  • C# HTTP functions
  • HTTP functions in custom runtimes

Why does the function fail to end?

Troubleshooting

If your problem persists, Contact us.

Additional information

To modify or delete a created trigger, see Manage triggers.