Object Storage Service:Resumable upload (OSS SDK for Go 1.0)

Usage notes

• In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS from other Alibaba Cloud services in the same region as OSS, use an internal endpoint. For more information about OSS regions and endpoints, see Regions and Endpoints.

• In this topic, access credentials are obtained from environment variables. For more information about how to configure access credentials, see Configure access credentials.

• This topic demonstrates creating an OSSClient instance with an OSS endpoint. For alternative configurations, such as using a custom domain or authenticating with credentials from Security Token Service (STS), see Configure a client (Go SDK V1).

• To use resumable upload, you must have the oss:PutObject permission. For more information, see Grant a custom policy.

• Upload progress is recorded in the checkpoint file. Ensure you have write permissions on it.

• The checkpoint file contains a checksum that must not be modified. If the file is damaged, re-upload all parts.

• If the local file changes during upload, re-upload all parts.

Implementation

Call Bucket.UploadFile to perform resumable upload with the following parameters.

Examples

The following sample code provides an example on how to perform resumable upload:

package main

import (
    "log"
    
    "github.com/aliyun/aliyun-oss-go-sdk/oss"
)

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

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

    // Specify the name of the bucket. Example: examplebucket. 
    bucket, err := client.Bucket("examplebucket")
    if err != nil {
        log.Fatalf("Failed to get bucket: %v", err)
    }

     // When you use UploadFile to perform resumable upload, the number of parts cannot exceed 10000. 
    // Specify the size of each part based on the size of the object that you want to upload. The size of each part ranges from 100 KB to 5 GB. Default value: 100 KB (100 x 1024). 
    // Use oss.Routines to set the number of parts that can be uploaded in parallel to 3. 
    // Specify the full path of the object. Do not include the bucket name in the full path. Example: exampledir/exampleobject.txt. 
    // Specify the full path of the local file. Example: D:\\localpath\\examplefile.txt. By default, if you do not specify the path of the local file, the file is uploaded from the path of the project to which the sample program belongs. 
    err = bucket.UploadFile("exampledir/exampleobject.txt", "D:\\localpath\\examplefile.txt", 100*1024, oss.Routines(3), oss.Checkpoint(true, ""))
    if err != nil {
        log.Fatalf("Failed to upload file: %v", err)
    }

    log.Println("File uploaded successfully.")
} 

FAQ

What do I do if "Too many parts, Please increase part size." is reported when I perform resumable upload?

References

• Complete resumable upload sample code is available on GitHub.

• API reference for the resumable upload method: UploadFile.