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HTTP Access to Cloud Functions

By configuring HTTP Access Service, you can make cloud functions respond to HTTP requests just like regular Web APIs.

How It Works​

When you access cloud functions through HTTP requests:

  1. Request Conversion: HTTP requests are automatically converted into a specific JSON format and passed to the cloud function
  2. Response Conversion: The return value of the cloud function is converted into a standard HTTP response and returned to the client

This way, you can call cloud functions using the familiar HTTP approach.

CORS Configuration​

HTTP Access Service naturally supports cross-origin requests. Simply add your domain to CloudBase Console/Environment Configuration/Security Domains, and web pages under that domain can normally access your cloud functions.

How Cloud Functions Receive HTTP Requests​

Request Parameter Format​

When you send an HTTP request to a cloud function, the cloud function receives an object containing all request information, which we call an integrated request:

{
    path: 'HTTP request path, e.g., /hello',
    httpMethod: 'HTTP request method, e.g., GET, POST',
    headers: {
        // HTTP request header information
    },
    queryStringParameters: {
        // URL query parameters, e.g., ?name=value
    },
    requestContext: {
        // CloudBase environment related information
    },
    body: 'HTTP request body content',
    isBase64Encoded: 'true/false, indicates whether body is Base64 encoded'
}

Actual Example​

Suppose you sent a GET request to https://env-id.service.tcloudbase.com/, the cloud function would receive parameters like this:

{
    path: '/',
    httpMethod: 'GET',
    headers: {
        'host': 'env-id.service.tcloudbase.com',
        'connection': 'close',
        'user-agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.88 Safari/537.36',
        'accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9',
        'accept-encoding': 'gzip, deflate, br',
        'accept-language': 'zh-CN,zh;q=0.9,en;q=0.8'
    },
    requestContext: {
        requestId: 'cdbb96328072184d19d3fcd243e8cc4d',
        envId: 'env-id',
        appId: 123456789,
        uin: 123456789
    },
    isBase64Encoded: false,
    body: ''
}

How Cloud Functions Return HTTP Responses​

Cloud functions have multiple ways to return data, and the system automatically converts these return values into standard HTTP responses.

Method 1: Directly Return Simple Data​

Return String​

The simplest way is to directly return a string:

exports.main = async function() {
    return "hello gateway";
};

The client will receive this HTTP response:

HTTP/1.1 200 OK
content-type: text/plain; charset=utf-8

hello gateway

Return JSON Object​

When returning an object, it will be automatically converted to JSON format:

exports.main = async function() {
    return {
        foo: "bar",
        message: "success"
    };
};

The client will receive:

HTTP/1.1 200 OK
content-type: application/json; charset=utf-8

{"foo":"bar","message":"success"}

Method 2: Return Integrated Response (Advanced Usage)​

If you need precise control over HTTP response status codes, response headers, and other information, you can return a specially formatted integrated response:

{
    "isBase64Encoded": true|false,  // Whether body is Base64 encoded
    "statusCode": 200,              // HTTP status code
    "headers": {                    // Custom response headers
        "headerName": "headerValue"
    },
    "body": "Response content"       // Response body
}

Example 1: Return HTML Page​

exports.main = async function() {
    return {
        statusCode: 200,
        headers: {
            "content-type": "text/html",
        },
        body: "<h1>Welcome to My Website</h1><p>This is an HTML page returned through cloud functions</p>",
    };
};

The browser will directly display this HTML page.

Example 2: Return JavaScript File​

exports.main = async function() {
    return {
        statusCode: 200,
        headers: {
            "content-type": "application/javascript",
        },
        body: 'console.log("Hello from Cloud Function!");',
    };
};

Example 3: Return Images and Other Binary Files​

For images, audio/video, and other binary files, you need to convert the content to Base64 encoding:

exports.main = async function() {
    return {
        isBase64Encoded: true,
        statusCode: 200,
        headers: {
            "content-type": "image/png",
        },
        body: "iVBORw0KGgoAAAANSUhEUgAAAMgAAADICAY...", // Base64 encoded image data
    };
};

The client will receive a complete PNG image.

Example 4: Implement Page Redirect​

You can also return a 302 status code to implement page redirection:

exports.main = async function(event) {
    const { path } = event;
    return {
        statusCode: 302,
        headers: {
            location: `https://tcb.cloud.tencent.com${path}`,
        },
    };
};

When users access your cloud function, they will be automatically redirected to the corresponding page on the Tencent CloudBase official website.