Object Storage Service:Manage symbolic links (Go SDK V1)

You can create a symbolic link that points to the current version of an object file.

The following code shows how to create a symbolic link:

package main

import (
	"log"
	"net/http"
	"strings"

	"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 set.
	provider, err := oss.NewEnvironmentVariableCredentialsProvider()
	if err != nil {
		log.Fatalf("Failed to create credentials provider: %v", err)
	}

	// 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, set the Endpoint as needed.
	// 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, set the region as needed.
	clientOptions := []oss.ClientOption{oss.SetCredentialsProvider(&provider)}
	clientOptions = append(clientOptions, oss.Region("yourRegion"))
	// Set 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 bucket name.
	bucketName := "yourBucketName"
	// Specify the name of the symbolic link.
	objectName := "yourSymlinkName"
	// Specify the name of the object file.
	targetObjectName := "yourObjectName"

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

	// Upload a file to the object file.
	err = bucket.PutObject(targetObjectName, strings.NewReader("target"))
	if err != nil {
		log.Fatalf("Failed to put object '%s': %v", targetObjectName, err)
	}

	// Create a symbolic link and obtain its version information.
	var retHeader http.Header
	err = bucket.PutSymlink(objectName, targetObjectName, oss.GetResponseHeader(&retHeader))
	if err != nil {
		log.Fatalf("Failed to create symlink '%s' to '%s': %v", objectName, targetObjectName, err)
	}

	// Print x-oss-version-id.
	versionId := oss.GetVersionId(retHeader)
	log.Printf("x-oss-version-id: %s", versionId)
}

By default, the GetSymlink operation retrieves the current version of a symbolic link. You can specify a version ID to retrieve a specific version. If the current version of the symbolic link is a delete marker, OSS returns 404 Not Found and includes x-oss-delete-marker = true and the version ID x-oss-version-id in the response header.

The following code shows how to retrieve a symbolic link:

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 set.
	provider, err := oss.NewEnvironmentVariableCredentialsProvider()
	if err != nil {
		log.Fatalf("Failed to create credentials provider: %v", err)
	}

	// 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, set the Endpoint as needed.
	// 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, set the region as needed.
	clientOptions := []oss.ClientOption{oss.SetCredentialsProvider(&provider)}
	clientOptions = append(clientOptions, oss.Region("yourRegion"))
	// Set 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 bucket name.
	bucketName := "yourBucketName"
	// Specify the name of the symbolic link.
	objectName := "yourSymlinkName"
	// Specify the version ID of the symbolic link.
	versionId := "yourObjectVersionId"

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

	// Get the specified version of the symbolic link.
	meta, err := bucket.GetSymlink(objectName, oss.VersionId(versionId))
	if err != nil {
		log.Fatalf("Failed to get symlink '%s' with version ID '%s': %v", objectName, versionId, err)
	}

	// Print the target of the symbolic link.
	symlinkTarget := meta.Get(oss.HTTPHeaderOssSymlinkTarget)
	log.Printf("Symlink Target: %s", symlinkTarget)
}