Getting Started

Download and Installation

Relevant Resources

• Download the COS XML SDK for JS resources here.
• Download the demo here.

Environmental Requirements

1. To use the SDK, your operating environment need to have Node.js and npm.
2. Log in to the COS Console, create a bucket, and get the bucket name and region name.
3. Log in to the CAM Console and get your project's SecretId and SecretKey.

For the definitions of parameters such as SecretId, SecretKey, and Bucket, see COS Glossary.

Installing the SDK

Install the SDK via npm; download npm.

npm i cos-nodejs-sdk-v5 --save

Getting Started

Initialization

Initializing with a Permanent Key

Please refer to the following sample code. Replace the SecretId, SecretKey, Bucket, and Region with actual values in your development environment to test file upload.

var COS = require('cos-nodejs-sdk-v5');
var cos = new COS({
    SecretId: 'COS_SECRETID',
    SecretKey: 'COS_SECRETKEY'
});

Initializing with a Temporary Key

The SDK for Node.js supports initialization with a temporary key. For more information on how to generate and use a temporary key, see Generating and Using Temporary Keys. The sample code is as shown below:

var request = require('request');
var cos = new COS({
    getAuthorization: function (options, callback) {
        // Get a temporary key asynchronously
        request({
            url: '../server/sts.php',
            data: {
                // The required parameters can be obtained from options
            }
        }, function (err, response, body) {
            try {
                var data = JSON.parse(body);
                var credentials = data.credentials;
            } catch(e) {}
            callback({
                    TmpSecretId: credentials.tmpSecretId,
                    TmpSecretKey: credentials.tmpSecretKey,
                    XCosSecurityToken: credentials.sessionToken,
                    ExpiredTime: data.expiredTime,
            });
        });
    }
});

Below are some examples of common APIs. For more detailed initialization methods, please see the demo.

Configuration Items

Constructor Parameter Descriptions

getAuthorization Callback Function Descriptions (Using Method 1)

getAuthorization: function(options, callback) { ... }

getAuthorization callback parameter descriptions:

After the temporary key is obtained, the callback returns an object. The attributes of the returned object are as shown below:

getAuthorization Callback Function Descriptions (Using Method 2)

getAuthorization: function(options, callback) { ... }

getAuthorization function callback parameter descriptions:

After the getAuthorization calculation is completed, the callback returns a signature string or an object:
If a signature string is returned, the string is the credential field "Authorization" in the authentication header to be used by the request.
If an object is returned, the attributes of the object are as shown below:

Getting an Authentication Credential

You can obtain the authentication credentials for your instance in three ways by passing in different parameters during instantiation:

1. During instantiation, pass in the SecretId and SecretKey, and each time a signature is required, it will be internally calculated by the instance.
2. During instantiation, pass in the getAuthorization callback, and each time a signature is required, it will be calculated and returned to the instance through this callback.
3. During instantiation, pass in the getSTS callback, and each time a temporary key is required, it will be returned to the instance through this callback for signature calculation within the instance during each request.

Creating a Bucket

cos.putBucket({
    Bucket: 'examplebucket-1250000000',
    Region: 'ap-beijing',
}, function (err, data) {
    console.log(err || data);
});

Querying Bucket List

cos.getService(function (err, data) {
    console.log(data && data.Buckets);
});

Uploading an Object

This API is suitable for uploading small files. For large files, please use the multipart upload API. For more information, see Object Operations.

cos.putObject({
    Bucket: 'examplebucket-1250000000',
    Region: 'ap-beijing',
    Key: 'destination path/picture.jpg',
    Body: fs.createReadStream('./picture.jpg'), // Pass in the prefix here
}, function (err, data) {
    console.log(err || data);
});

Querying Object List

cos.getBucket({
    Bucket: 'examplebucket-1250000000',
    Region: 'ap-beijing',
    Prefix: 'exampledir/', // Pass in the prefix of the files to be listed
}, function (err, data) {
    console.log(err || data.Contents);
});

Downloading an Object

cos.getObject({
    Bucket: 'examplebucket-1250000000',
    Region: 'ap-beijing',
    Key: 'exampleobject.txt',
    Output: fs.createWriteFile(__dirname + '/exampleobject.txt'),
}, function (err, data) {
    console.log(err || data.Body);
});

Deleting an Object

cos.deleteObject({
    Bucket: 'examplebucket-1250000000',
    Region: 'ap-beijing',
    Key: 'picture.jpg',
}, function (err, data) {
    console.log(err || data);
});