tencent cloud

Download and Installation

Relevant resources

• Download the COS XML SDK resources for Node.js here.
• SDK download: XML Node.js SDK.
• Download the demo here.
• For the complete sample code, see SDK Sample Code.
• For the SDK changelog, see Changelog.

Note：

If you encounter errors such as non-existent functions or methods when using the SDK, you can update the SDK to the latest version and try again.

Environmental dependencies

1. The SDK requires your runtime environment to include Node.js (v6 or later) 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.

Note：

For the definition of terms such as SecretId, SecretKey, and Bucket, see COS Glossary.

Installing SDK

Install the SDK through npm which can be downloaded here.

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

Getting Started

Initialization

Note：

• We recommend you use a temporary key as instructed in Generating and Using Temporary Keys to call the SDK for security purposes. When you apply for a temporary key, follow the Notes on Principle of Least Privilege to avoid leaking resources besides your buckets and objects.
• If you must use a permanent key, we recommend you follow the Notes on Principle of Least Privilege to limit the scope of permission on the permanent key.

Using a temporary key for initialization (recommended)

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

var request = require('request');
var COS = require('cos-nodejs-sdk-v5');
var cos = new COS({
    getAuthorization: function (options, callback) {
        // It will not be called during initialization and will be entered only when a COS method such as `cos.putObject` is called.
        // Get a temporary key asynchronously.
        request({
            url: 'https://example.com/sts',
            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) {}
            if (!data || !credentials) return console.error('credentials invalid');
            callback({
                TmpSecretId: credentials.tmpSecretId, // tmpSecretId of the temporary key
                TmpSecretKey: credentials.tmpSecretKey, // tmpSecretKey of the temporary key
                SecurityToken: credentials.sessionToken, // sessionToken of the temporary key
                ExpiredTime: data.expiredTime, // Expiration timestamp of the temporary key, which is calculated by adding durationSeconds to the timestamp when applying for the temporary key 
            });
        });
    }
});

Using a permanent key for initialization (not recommended)

When using a permanent key for initialization, store the key properly to prevent leakage.
First, log in to the CAM console, and get your SecretId and SecretKey from the Access Key page.
Replace SecretId, SecretKey, bucket, and region with the actual values in your development environment. To test file upload, see the following sample code.

// Log in to https://console.tencentcloud.com/cam/capi to check and manage the SecretId and SecretKey of your project.
var COS = require('cos-nodejs-sdk-v5');
var cos = new COS({
    SecretId: process.env.SecretId, // User `SecretId`. We recommend you obtain it from the environment variable. In addition, we recommended you use a sub-account key and follow the principle of least privilege to reduce risks. For information about how to obtain a sub-account key, visit https://www.tencentcloud.com/document/product/598/37140?from_cn_redirect=1.
    SecretKey: process.env.SecretKey, // User `SecretKey`. We recommend you obtain it from the environment variable. In addition, we recommend you use a sub-account key and follow the principle of least privilege to reduce risks. For information about how to obtain a sub-account key, visit https://www.tencentcloud.com/document/product/598/37140?from_cn_redirect=1.
});

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

Configuration item

Constructor parameters

Parameter	Description	Type	Required
SecretId	User SecretId	String	Yes
SecretKey	User SecretKey	String	Yes
FileParallelLimit	Number of concurrent file uploads in the same instance. Default value: 3	Number	No
ChunkParallelLimit	Number of concurrent part uploads for the same uploaded file. Default value: 3	Number	No
ChunkRetryTimes	Number of retries for multipart upload failure. Default value: 2 (a request will be made 3 time in total, including the initial one)	Number	No
ChunkSize	Part size in the multipart upload in bytes. Default value: 1048576 (1 MB)	Number	No
SliceSize	When files are uploaded in batches using uploadFiles, if the file size is greater than the value of this parameter (measured in bytes), multipart upload is used; otherwise, simple upload is used. Default value: 1048576 (1 MB)	Number	No
CopyChunkParallelLimit	Number of concurrent part uploads for the same multipart copy operation. Default value: 20	Number	No
CopyChunkSize	Number of bytes in each part during a multipart copy operation with sliceCopyFile. Default value: 10485760 (10 MB)	Number	No
CopySliceSize	When a file is copied using sliceCopyFile, if the file size is greater than the value of this parameter, multipart copy is used; otherwise, simple copy is used. Default value: 10485760 (10 MB)	Number	No
ProgressInterval	Callback frequency of the upload progress callback method onProgress in milliseconds. Default value: 1000	Number	No
Protocol	The protocol used when the request is made. Valid values: https:, http:. By default, http: is used when the current page is determined to be in http: format; otherwise, https: is used	String	No
ServiceDomain	The request domain name when getService is called, such as service.cos.myqcloud.com	String	No
Domain	Custom request domain name used to call a bucket or object API. You can use a template such as "{Bucket}.cos.{Region}.myqcloud.com" which will use the bucket and region information passed in the replacement parameters when an API is called.	String	No
UploadQueueSize	The maximum size of the upload queue. If the maximum is exceeded, failed, completed, and canceled tasks will be cleared. Default value: 1000	Number	No
ForcePathStyle	Forces the use of a suffix when sending requests. The suffixed bucket will be placed in the pathname after the domain name, and the bucket will be added to the signature pathname for calculation. Default value: false	Boolean	No
UploadCheckContentMd5	Forces the verification of Content-MD5 for file uploads, which calculates the MD5 checksum of the file request body and places it in the Content-MD5 field of the header. Default value: false	Boolean	No
Timeout	Timeout period in milliseconds. Default value: 0, indicating no timeout period.	Number	No
KeepAlive	Indicates that more than one request is sent over one TCP connection. Default value: true. This parameter is recommended for a large number of concurrent requests.	Boolean	No
StrictSsl	Strict verification of the HTTPS certificate. Default value: true	Boolean	No
Proxy	Uses an HTTP proxy when making requests, such as: http://127.0.0.1:8080	String	No
getAuthorization	Callback method for getting the signature. If there is no SecretId or SecretKey, this parameter is required	Function	No
UseAccelerate	Whether to enable a global acceleration endpoint. Default value: false. If you set the value to true, you need to enable global acceleration for the bucket. For more information, see Enabling Global Acceleration.	Boolean	No

getAuthorization Callback function description (Format 1)

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

getAuthorization function parameters:

Parameter	Description	Type
options	Required for getting the signature	Object
- Bucket	Bucket name in the format of BucketName-APPID. The bucket name entered here must be in this format	String
- Region	Bucket region. For the enumerated values, see Regions and Access Endpoints.	String
callback	Callback method after the temporary key is obtained	Function

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

Attribute	Description	Type	Required
TmpSecretId	tmpSecretId of the obtained temporary key	String	Yes
TmpSecretKey	tmpSecretKey of the obtained temporary key	String	Yes
SecurityToken	sessionToken of the obtained temporary key, which corresponds to the x-cos-security-token field in the header	String	Yes
StartTime	The timestamp in seconds of when you obtained the key, such as 1580000000. Passing in this parameter as the signature start time can avoid signature expiration issues due to time deviation on the frontend.	String	No
ExpiredTime	expiredTime of the obtained temporary key measured in seconds, i.e., the timeout timestamp, such as 1580000900	String	Yes

getAuthorization Callback function description (Format 2)

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

getAuthorization function parameters:

Parameter	Description	Type
options	Parameter object for getting the signature	Object
- Method	Method of the current request	String
- Pathname	Request path used for signature calculation	String
- Key	ObjectKey (object name) is the unique ID of an object in a bucket. For more information, see Object Overview.	String
- Query	Query parameter in the current request. Format: {key: 'val'}	Object
- Headers	Headers in the current request. Format: {key: 'val'}	Object
callback	Callback after the temporary key is obtained	Function

Once the getAuthorization callback function is finished, it returns one of the following:
An Authorization string.
An object whose attributes are listed as follows:

Attribute	Description	Type	Required
Authorization	Calculated signature string	String	Yes
SecurityToken	sessionToken of the obtained temporary key, which corresponds to the x-cos-security-token field in the header	String	No

Getting an authentication credential

There are three ways to get the authentication credentials for your instance by passing in different parameters during instantiation:

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

How to use

Callback method

The callback method is used by default in the documentation. Below is the sample code:

// The initialization process and upload parameters are omitted here.
var cos = new COS({ ... });
cos.uploadFile({ ... }, function(err, data) {
  if (err) {
    console.log('Upload failed', err);
  } else {
    console.log('Uploaded successfully', data);
  }
});

Promise

The SDK also supports calling through the promise method. For example, the code of the callback method above is equivalent to the following code:

// The initialization process and upload parameters are omitted here.
var cos = new COS({ ... });
cos.uploadFile({ ... }).then(data => {
  console.log('Uploaded successfully', data);
}).catch(err => {
  console.log('Upload failed', err);
});

Sync method

The sync method is based on JavaScript's async and await. The code of the callback method above is equivalent to the following code:

async function upload() {
  // The initialization process and upload parameters are omitted here.
  var cos = new COS({ ... });
  try {
    var data = await cos.uploadFile({ ... });
    return { err: null, data: data }
  } catch (err) {
    return { err: err, data: null };
  }
}
// The returned value of the request can be obtained synchronously. Here is only an example. The format of the actual returned data can be customized.
var uploadResult = await upload();
if (uploadResult.err) {
  console.log('Upload failed', uploadResult.err);
} else {
  console.log('Uploaded successfully', uploadResult.data);
}

Note：

cos.getObjectUrl currently only supports the callback method.

Tips

In most cases, you only need to create a COS SDK instance, and use it directly where SDK methods need to be called.

var cos = new COS({
  ....
});

/* Self-encapsulated upload method */
function myUpload() {
  // COS SDK instances do not need to be created in each method
  // var cos = new COS({
  //   ...
  // });
  cos.putObject({
    ....
  });
}

/* Self-encapsulated deletion method */
function myDelete() {
  // COS SDK instances do not need to be created in each method
  // var cos = new COS({
  //   ...
  // });
  cos.deleteObject({
    ....
  });
}

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

Creating a bucket

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

Querying the bucket list

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

Uploading an object

This API is used to upload small files. For large files, use the multipart upload API. For more information, see Object Operations.

cos.putObject({
    Bucket: 'examplebucket-1250000000', /* Required */
    Region: 'COS_REGION', /* Required */
    Key: 'exampleobject', /* Required */
    StorageClass: 'STANDARD',
    Body: fs.createReadStream('./exampleobject'), // Uploading file object
    onProgress: function(progressData) {
        console.log(JSON.stringify(progressData));
    }
}, function(err, data) {
    console.log(err || data);
});

Querying objects

cos.getBucket({
    Bucket: 'examplebucket-1250000000', /* Required */
    Region: 'COS_REGION', /* Required */
    Prefix: 'a/', /*Optional*/
}, function(err, data) {
    console.log(err || data.Contents);
});

Downloading an object

cos.getObject({
    Bucket: 'examplebucket-1250000000', /* Required */
    Region: 'COS_REGION', /* Required */
    Key: 'exampleobject', /* Required */
    Output: fs.createWriteStream('./exampleobject'),
}, function(err, data) {
    console.log(err || data);
});

Deleting an object

cos.deleteObject({
    Bucket: 'examplebucket-1250000000', /* Required */
    Region: 'COS_REGION', /* Required */
    Key: 'exampleobject'       /* Required */
}, function(err, data) {
    console.log(err || data);
});

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