Manage symbolic links (Go SDK V1)

PutSymlink creates a symbolic link pointing to the current version of a target object. OSS automatically assigns a version ID to the new symlink and returns it in the x-oss-version-id response header.

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.
	// Endpoint: https://oss-cn-hangzhou.aliyuncs.com (China (Hangzhou) region public endpoint)
	// Region: cn-hangzhou
	clientOptions := []oss.ClientOption{oss.SetCredentialsProvider(&provider)}
	clientOptions = append(clientOptions, oss.Region("cn-hangzhou"))
	clientOptions = append(clientOptions, oss.AuthVersion(oss.AuthV4))
	client, err := oss.New("https://oss-cn-hangzhou.aliyuncs.com", "", "", clientOptions...)
	if err != nil {
		log.Fatalf("Failed to create OSS client: %v", err)
	}

	bucketName := "examplebucket"
	objectName := "exampledir/examplesymlink"         // Name of the symlink to create
	targetObjectName := "exampledir/exampleobject.txt" // Name of the target object

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

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

	// Create the symlink.
	// OSS returns the assigned version ID in the x-oss-version-id response header.
	var retHeader http.Header
	err = bucket.PutSymlink(objectName, targetObjectName, oss.GetResponseHeader(&retHeader))
	if err != nil {
		log.Fatalf("Failed to create symlink '%s' -> '%s': %v", objectName, targetObjectName, err)
	}

	// Print the version ID assigned to the new symlink.
	versionId := oss.GetVersionId(retHeader)
	log.Printf("x-oss-version-id: %s", versionId)
}

GetSymlink retrieves the current version of a symbolic link by default. Pass oss.VersionId to retrieve a specific version.

If the current version of the symlink is a delete marker, OSS returns 404 Not Found with x-oss-delete-marker: true and the version ID in the response header.

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.
	// Endpoint: https://oss-cn-hangzhou.aliyuncs.com (China (Hangzhou) region public endpoint)
	// Region: cn-hangzhou
	clientOptions := []oss.ClientOption{oss.SetCredentialsProvider(&provider)}
	clientOptions = append(clientOptions, oss.Region("cn-hangzhou"))
	clientOptions = append(clientOptions, oss.AuthVersion(oss.AuthV4))
	client, err := oss.New("https://oss-cn-hangzhou.aliyuncs.com", "", "", clientOptions...)
	if err != nil {
		log.Fatalf("Failed to create OSS client: %v", err)
	}

	bucketName := "examplebucket"
	objectName := "exampledir/examplesymlink"                             // Name of the symlink to retrieve
	versionId := "CAEQMhiBgMDJgZCA0BYiIGY2Y2VkMTQyYjkzNDVjNTgzMTY2****" // Version ID of the symlink; omit to get the current version

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

	// Retrieve the specified version of the symlink.
	// The symlink target is stored in the x-oss-symlink-target response header,
	// accessible via the oss.HTTPHeaderOssSymlinkTarget constant.
	meta, err := bucket.GetSymlink(objectName, oss.VersionId(versionId))
	if err != nil {
		log.Fatalf("Failed to get symlink '%s' (version: %s): %v", objectName, versionId, err)
	}

	symlinkTarget := meta.Get(oss.HTTPHeaderOssSymlinkTarget)
	log.Printf("Symlink target: %s", symlinkTarget)
}