Restore a file (Go SDK V1)

How it works

Restoring an Archive object requires three steps:

1. Call bucket.GetObjectDetailedMeta to read the X-Oss-Storage-Class header and confirm the object is in the Archive storage class.

2. Call bucket.RestoreObject to submit the restore request.

3. Poll bucket.GetObjectDetailedMeta until X-Oss-Restore no longer returns ongoing-request="true", which indicates the restore is complete.

Prerequisites

Before you begin, ensure that you have:

• Configured access credentials as environment variables OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET. For configuration steps, see Configure access credentials.

• The oss:RestoreObject permission on the target object. For permission setup, see Attach a custom policy to a RAM user.

Usage notes

• The examples use the public endpoint for the China (Hangzhou) region. To access OSS from another Alibaba Cloud service in the same region, use the internal endpoint instead. For a full list of endpoints, see Regions and endpoints.

• The OSSClient instance in these examples is created with an OSS endpoint. To create one using a custom domain name or Security Token Service (STS), see Configure OSSClient instances.

Example code

The following example restores an Archive object by version ID:

package main

import (
	"log"
	"time"

	"github.com/aliyun/aliyun-oss-go-sdk/oss"
)

func main() {
	// Obtain access credentials from environment variables. Before you run this code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set.
	provider, err := oss.NewEnvironmentVariableCredentialsProvider()
	if err != nil {
		log.Fatalf("Failed to create credentials provider: %v", err)
	}

	var clientOptions []oss.ClientOption
	// Create an OSSClient instance.
	// Set yourEndpoint to the endpoint of the bucket. For example, for a bucket in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. For other regions, use the actual endpoint.
	endpoint := "http://oss-cn-hangzhou.aliyuncs.com"
	// Set yourRegion to the region where the bucket is located. For example, for a bucket in the China (Hangzhou) region, set the region to cn-hangzhou. For other regions, use the actual region.
	clientOptions = append(clientOptions, oss.SetCredentialsProvider(&provider))
	clientOptions = append(clientOptions, oss.Region("cn-hangzhou"))
	// Set the signature version.
	clientOptions = append(clientOptions, oss.AuthVersion(oss.AuthV4))
	client, err := oss.New(endpoint, "", "", clientOptions...)
	if err != nil {
		log.Fatalf("Failed to create OSS client: %v", err)
	}

	// Specify the bucket name.
	bucketName := "examplebucket"
	// Specify the full path of the Archive object. Do not include the bucket name. Example: exampledir/exampleobject.txt.
	objectName := "exampledir/exampleobject.txt"
	// Specify the version ID of the object.
	versionId := "yourObjectVersionId"

	// Create a bucket instance.
	bucket, err := client.Bucket(bucketName)
	if err != nil {
		log.Fatalf("Failed to get bucket '%s': %v", bucketName, err)
	}

	// Check whether the object is of the Archive storage class.
	meta, err := bucket.GetObjectDetailedMeta(objectName, oss.VersionId(versionId))
	if err != nil {
		log.Fatalf("Failed to get object detailed meta: %v", err)
	}

	if meta.Get("X-Oss-Storage-Class") == string(oss.StorageArchive) {
		log.Println("Object is an archive type, initiating restore process...")

		err = bucket.RestoreObject(objectName, oss.VersionId(versionId))
		if err != nil {
			log.Fatalf("Failed to restore object: %v", err)
		}

		// Wait for the restore operation to complete.
		for {
			meta, err = bucket.GetObjectDetailedMeta(objectName, oss.VersionId(versionId))
			if err != nil {
				log.Fatalf("Failed to get object detailed meta during restore: %v", err)
			}

			restoreStatus := meta.Get("X-Oss-Restore")
			log.Printf("x-oss-restore: %s", restoreStatus)

			if restoreStatus != "ongoing-request=\"true\"" {
				break
			}

			log.Println("Restore in progress, waiting...")
			time.Sleep(1000 * time.Second)
		}

		log.Println("Object restored successfully.")
	} else {
		log.Println("Object is not an archive type, no need to restore.")
	}
}

References

For the full API specification, see RestoreObject.