improve oss backend according to review suggestion

backend/init/init.go

@@ -17,6 +17,7 @@ import (
 	backendGCS "github.com/hashicorp/terraform/backend/remote-state/gcs"
 	backendinmem "github.com/hashicorp/terraform/backend/remote-state/inmem"
 	backendManta "github.com/hashicorp/terraform/backend/remote-state/manta"
+	backendOSS "github.com/hashicorp/terraform/backend/remote-state/oss"
 	backendS3 "github.com/hashicorp/terraform/backend/remote-state/s3"
 	backendSwift "github.com/hashicorp/terraform/backend/remote-state/swift"
 )
@@ -51,6 +52,7 @@ func init() {
 		"etcdv3":  func() backend.Backend { return backendetcdv3.New() },
 		"gcs":     func() backend.Backend { return backendGCS.New() },
 		"manta":   func() backend.Backend { return backendManta.New() },
+		"oss":     func() backend.Backend { return backendOSS.New() },
 	}
 
 	// Add the legacy remote backends that haven't yet been convertd to

backend/remote-state/oss/backend.go

@@ -0,0 +1,201 @@
+package oss
+
+import (
+	"context"
+	"fmt"
+	"github.com/aliyun/aliyun-oss-go-sdk/oss"
+	"github.com/denverdino/aliyungo/common"
+	"github.com/denverdino/aliyungo/location"
+	"github.com/hashicorp/terraform/backend"
+	"github.com/hashicorp/terraform/helper/schema"
+	"github.com/hashicorp/terraform/terraform"
+	"os"
+	"strings"
+
+	"log"
+)
+
+// New creates a new backend for OSS remote state.
+func New() backend.Backend {
+	s := &schema.Backend{
+		Schema: map[string]*schema.Schema{
+			"access_key": &schema.Schema{
+				Type:        schema.TypeString,
+				Optional:    true,
+				Description: "Alibaba Cloud Access Key ID",
+				DefaultFunc: schema.EnvDefaultFunc("ALICLOUD_ACCESS_KEY", os.Getenv("ALICLOUD_ACCESS_KEY_ID")),
+			},
+
+			"secret_key": &schema.Schema{
+				Type:        schema.TypeString,
+				Optional:    true,
+				Description: "Alibaba Cloud Access Secret Key",
+				DefaultFunc: schema.EnvDefaultFunc("ALICLOUD_SECRET_KEY", os.Getenv("ALICLOUD_ACCESS_KEY_SECRET")),
+			},
+
+			"security_token": &schema.Schema{
+				Type:        schema.TypeString,
+				Optional:    true,
+				Description: "Alibaba Cloud Security Token",
+				DefaultFunc: schema.EnvDefaultFunc("ALICLOUD_SECURITY_TOKEN", os.Getenv("SECURITY_TOKEN")),
+			},
+
+			"region": &schema.Schema{
+				Type:        schema.TypeString,
+				Optional:    true,
+				Description: "The region of the OSS bucket.",
+				DefaultFunc: schema.EnvDefaultFunc("ALICLOUD_REGION", os.Getenv("ALICLOUD_DEFAULT_REGION")),
+			},
+
+			"bucket": &schema.Schema{
+				Type:        schema.TypeString,
+				Required:    true,
+				Description: "The name of the OSS bucket",
+			},
+
+			"path": &schema.Schema{
+				Type:        schema.TypeString,
+				Required:    true,
+				Description: "The path relative to your object storage directory where the state file will be stored.",
+			},
+
+			"name": &schema.Schema{
+				Type:        schema.TypeString,
+				Optional:    true,
+				Description: "The name of the state file inside the bucket",
+				ValidateFunc: func(v interface{}, s string) ([]string, []error) {
+					if strings.HasPrefix(v.(string), "/") || strings.HasSuffix(v.(string), "/") {
+						return nil, []error{fmt.Errorf("name can not start and end with '/'")}
+					}
+					return nil, nil
+				},
+				Default: "terraform.tfstate",
+			},
+
+			"lock": &schema.Schema{
+				Type:        schema.TypeBool,
+				Optional:    true,
+				Description: "Whether to lock state access. Defaults to true",
+				Default:     true,
+			},
+
+			"encrypt": &schema.Schema{
+				Type:        schema.TypeBool,
+				Optional:    true,
+				Description: "Whether to enable server side encryption of the state file",
+				Default:     false,
+			},
+
+			"acl": &schema.Schema{
+				Type:        schema.TypeString,
+				Optional:    true,
+				Description: "Object ACL to be applied to the state file",
+				Default:     "",
+				ValidateFunc: func(v interface{}, k string) ([]string, []error) {
+					if value := v.(string); value != "" {
+						acls := oss.ACLType(value)
+						if acls != oss.ACLPrivate && acls != oss.ACLPublicRead && acls != oss.ACLPublicReadWrite {
+							return nil, []error{fmt.Errorf(
+								"%q must be a valid ACL value , expected %s, %s or %s, got %q",
+								k, oss.ACLPrivate, oss.ACLPublicRead, oss.ACLPublicReadWrite, acls)}
+						}
+					}
+					return nil, nil
+				},
+			},
+		},
+	}
+
+	result := &Backend{Backend: s}
+	result.Backend.ConfigureFunc = result.configure
+	return result
+}
+
+type Backend struct {
+	*schema.Backend
+
+	// The fields below are set from configure
+	ossClient *oss.Client
+
+	bucketName           string
+	statePath            string
+	stateName            string
+	serverSideEncryption bool
+	acl                  string
+	security_token       string
+	endpoint             string
+	lock                 bool
+}
+
+func (b *Backend) configure(ctx context.Context) error {
+	if b.ossClient != nil {
+		return nil
+	}
+
+	// Grab the resource data
+	d := schema.FromContextBackendConfig(ctx)
+
+	b.bucketName = d.Get("bucket").(string)
+	dir := strings.Trim(d.Get("path").(string), "/")
+	if strings.HasPrefix(dir, "./") {
+		dir = strings.TrimPrefix(dir, "./")
+
+	}
+
+	b.statePath = dir
+	b.stateName = d.Get("name").(string)
+	b.serverSideEncryption = d.Get("encrypt").(bool)
+	b.acl = d.Get("acl").(string)
+	b.lock = d.Get("lock").(bool)
+
+	access_key := d.Get("access_key").(string)
+	secret_key := d.Get("secret_key").(string)
+	security_token := d.Get("security_token").(string)
+	endpoint := os.Getenv("OSS_ENDPOINT")
+	if endpoint == "" {
+		region := common.Region(d.Get("region").(string))
+		if end, err := b.getOSSEndpointByRegion(access_key, secret_key, security_token, region); err != nil {
+			return err
+		} else {
+			endpoint = end
+		}
+	}
+
+	log.Printf("[DEBUG] Instantiate OSS client using endpoint: %#v", endpoint)
+	var options []oss.ClientOption
+	if security_token != "" {
+		options = append(options, oss.SecurityToken(security_token))
+	}
+	options = append(options, oss.UserAgent(fmt.Sprintf("HashiCorp-Terraform-v%s", strings.TrimSuffix(terraform.VersionString(), "-dev"))))
+
+	if client, err := oss.New(fmt.Sprintf("http://%s", endpoint), access_key, secret_key, options...); err != nil {
+		return err
+	} else {
+		b.ossClient = client
+	}
+
+	return nil
+}
+
+func (b *Backend) getOSSEndpointByRegion(access_key, secret_key, security_token string, region common.Region) (string, error) {
+
+	endpointClient := location.NewClient(access_key, secret_key)
+	endpointClient.SetSecurityToken(security_token)
+	endpoints, err := endpointClient.DescribeEndpoints(&location.DescribeEndpointsArgs{
+		Id:          region,
+		ServiceCode: "oss",
+		Type:        "openAPI",
+	})
+	if err != nil {
+		return "", fmt.Errorf("Describe endpoint using region: %#v got an error: %#v.", region, err)
+	}
+	endpointItem := endpoints.Endpoints.Endpoint
+	endpoint := ""
+	if endpointItem != nil && len(endpointItem) > 0 {
+		endpoint = endpointItem[0].Endpoint
+	} else {
+		endpoint = fmt.Sprintf("oss-%s.aliyuncs.com", string(region))
+	}
+
+	return endpoint, nil
+}