How to use object tags for OSS on CloudBox-Object Storage Service(OSS)-阿里云帮助中心

OSS on CloudBox lets you use tags to classify objects in an OSS on CloudBox bucket. Based on these tags, you can set lifecycle rules and access permissions for the objects.

Tagging rules

Objects are tagged with key-value pairs. You can add tags either when uploading new objects or to existing objects stored within your bucket.

Up to 10 tags with unique keys can be added to an object.
The maximum length for keys is 128 characters, and for values, 256 characters. Both are case-sensitive.
The valid character set for tags includes uppercase and lowercase letters, numbers, spaces, and the following symbols:
+ - = . _ : /.
When configuring tags via HTTP headers, you must URL-encode both the tag keys and values.

Usage notes

Only the bucket owner and users who have the oss-cloudbox:PutObjectTagging permission can add or modify object tags.
You can add tags to an object when you perform simple upload, multipart upload, append upload, and copy operations. You can also add tags to uploaded objects.
Editing the tags of an object does not affect its Last‑Modified timestamp.

Scenarios

Configure lifecycle rules based on tags
For efficient management of your storage resources and cost optimization, you can apply specific tags to objects that are generated periodically and do not require long-term retention, then configure lifecycle rules to automatically delete these tagged objects at predefined intervals.
For example, you can configure the following lifecycle rule to delete objects prefixed with dir1 and tagged with key1:value1 30 days after these objects are last updated:
```
<LifecycleConfiguration>
 <Rule>
  <ID>rule1</ID>
  <Prefix>dir1</Prefix>
  <Tag><Key>key1</Key><Value>value1</Value></Tag>
  <Status>Enabled</Status>
  <Expiration>
    <Days>30</Days>
  </Expiration>
 </Rule>
</LifecycleConfiguration>
```

Authorize a RAM user to access objects that have specific tags

You can configure a RAM policy to grant a RAM user permissions to access objects that have the tags status:ok and key1:value1 in an OSS on CloudBox bucket named examplebucket. The ID of the CloudBox is cb-f8z7yvzgwfkl9q0h****.

{
    "Version": "1",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "oss-cloudbox:GetObject"
            ],
            "Resource": [
                "acs:oss-cloudbox:*:174649585760****:cloudbox/cb-f8z7yvzgwfkl9q0h****/bucket/examplebucket/*"
            ],
            "Condition": {
                "StringEquals": {
                    "oss-cloudbox:ExistingObjectTag/status":"ok",
                    "oss-cloudbox:ExistingObjectTag/key1":"value1"
                }
            }
        }
    ]
}

Procedure

Use Alibaba Cloud SDKs

You can use the Java SDK to add tags only during a simple upload. The Java SDK must be version 3.15.0 or later.

import com.aliyun.oss.ClientException;
import com.aliyun.oss.OSS;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.OSSException;
import com.aliyun.oss.model.*;
import java.io.ByteArrayInputStream;
import java.util.HashMap;
import java.util.Map;
import com.aliyun.oss.common.auth.DefaultCredentialProvider;
import com.aliyun.oss.common.comm.SignVersion;
import com.aliyun.oss.ClientBuilderConfiguration;
import com.aliyun.oss.common.auth.CredentialsProviderFactory;
import com.aliyun.oss.common.auth.EnvironmentVariableCredentialsProvider;

public class Demo {
    public static void main(String[] args) throws Exception {
        // Specify the data endpoint of the OSS on CloudBox bucket.
        String endpoint = "https://cb-f8z7yvzgwfkl9q0h****.cn-hangzhou.oss-cloudbox.aliyuncs.com";
        // Obtain access credentials from environment variables. Before you run this sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set.
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // Specify the name of the OSS on CloudBox bucket, for example, examplebucket.
        String bucketName = "examplebucket";
        // Specify the region where the OSS on CloudBox bucket is located.
        String region = "cn-hangzhou";
        // Specify the CloudBox ID.
        String cloudBoxId = "cb-f8z7yvzgwfkl9q0h****";
        // Specify the full path of the object. The full path cannot contain the bucket name. Example: exampledir/exampleobject.txt.
        String objectName = "exampledir/exampleobject.txt";

        // Create an OSSClient instance.
        // When the OSSClient instance is no longer in use, call the shutdown method to release the resources.
        ClientBuilderConfiguration conf = new ClientBuilderConfiguration();
        conf.setSignatureVersion(SignVersion.V4);
        OSS ossClient = OSSClientBuilder.create()
                .endpoint(endpoint)
                .credentialsProvider(new DefaultCredentialProvider(credentialsProvider.getCredentials()))
                .clientConfiguration(conf)
                .region(region)
                .cloudBoxId(cloudBoxId)
                .build();

        try {
            Map<String, String> tags = new HashMap<String, String>();
            // Specify the tag key, such as owner, and the tag value, such as John.
            tags.put("owner", "John");
            tags.put("type", "document");

            // Set the tag information in the HTTP header.
            ObjectMetadata metadata = new ObjectMetadata();
            metadata.setObjectTagging(tags);

            // Set the content of the object to upload.
            String content = "yourContent";
            ossClient.putObject(bucketName, objectName, new ByteArrayInputStream(content.getBytes()), metadata);
        } catch (OSSException oe) {
            System.out.println("Caught an OSSException, which means your request made it to OSS, "
                    + "but was rejected with an error response for some reason.");
            System.out.println("Error Message:" + oe.getErrorMessage());
            System.out.println("Error Code:" + oe.getErrorCode());
            System.out.println("Request ID:" + oe.getRequestId());
            System.out.println("Host ID:" + oe.getHostId());
        } catch (ClientException ce) {
            System.out.println("Caught an ClientException, which means the client encountered "
                    + "a serious internal problem while trying to communicate with OSS, "
                    + "such as not being able to access the network.");
            System.out.println("Error Message:" + ce.getMessage());
        } finally {
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }
    }
}

Use ossutil

For more information about how to use ossutil to add object tags, see put-object-tagging.

Use the REST API

If you have advanced customization requirements, you can make REST API requests directly. This requires you to manually write code to calculate the signature. For more information, see PutObjectTagging.