Object Storage Service:Authorize access by using OSS SDK for Python

1. Log on to the RAM console.

2. In the left-side navigation pane, choose Identities > Users.

3. On the Users page, click Create User.

4. Configure the Logon Name and Display Name parameters.

5. In the Access Mode section, select OpenAPI Access. Then, click OK.

6. Complete security verification as prompted.

7. Copy the AccessKey pair (AccessKey ID and AccessKey secret).

   Important

   You can obtain the AccessKey secret of a RAM user only when you create the RAM user. You must keep the AccessKey secret safely to prevent credential leaks.

1. On the Users page, find the RAM user that you created and click Add Permissions in the Actions column.

2. In the Policy section of the Grant Permission panel, select the AliyunSTSAssumeRoleAccess policy.

   Note

   The AliyunSTSAssumeRoleAccess policy allows a RAM user to call the AssumeRole operation. The permissions of the policy are independent of the permissions required for the RAM user to obtain temporary access credentials from STS and initiate requests to OSS.

   

3. Click Grant permissions.

1. In the left-side navigation pane, choose Identities > Roles.

2. Click Create Role. In the Select Role Type step of the Create Role wizard, set Select Trusted Entity to Alibaba Cloud Account and click Next.

3. In the Configure Role step of the Create Role wizard, set RAM Role Name to RamOssTest and Select Trusted Alibaba Cloud Account to Current Alibaba Cloud Account.

4. Click OK. After the role is created, click Close.

5. On the Roles page, enter RamOssTest in the search box, click the search icon, and click RamOssTest in the search result.

6. Click Copy on the right side of the RamOssTest page to save the Alibaba Cloud Resource Name (ARN) of the role.

1. Allow the RAM role to upload and download objects by attaching a custom policy to the RAM role.

   1. In the left-side navigation pane, choose Permissions > Policies.

   2. On the Policies page, click Create Policy.

   3. On the Create Policy page, click JSON. Modify the script in the policy editor to grant the role the permissions to upload objects to and download objects from a bucket named examplebucket. The following sample code provides an example on how to grant the role the permissions.

      Warning

      The following example is only for reference. You must configure fine-grained RAM policies based on your requirements to prevent granting excessive permissions to users. For more information about how to configure fine-grained RAM policies, see Example 9: Use RAM or STS to authorize users to access OSS resources.

      {
          "Version": "1",
          "Statement": [
           {
                 "Effect": "Allow",
                 "Action": [
                   "oss:PutObject",
                   "oss:GetObject"
                 ],
                 "Resource": [
                   "acs:oss:*:*:examplebucket",
                   "acs:oss:*:*:examplebucket/*"
                 ]
           }
          ]
      }

   4. Click Next to edit policy information.

   5. In the Basic Information section, set Name to RamTestPolicy and click OK.

2. Attach the custom policy to the RamOssTest role.

   1. In the left-side navigation pane, choose Identities > Roles.

   2. On the Roles page, find the RamOssTest role.

   3. Click Grant Permission in the Actions column.

   4. In the Grant Permission panel, select Custom Policy from the drop-down list in the Policy section and select the RamTestPolicy policy.

   5. Click Grant permissions.

Temporary access credentials contain a security token and a temporary AccessKey pair. An AccessKey pair consists of an AccessKey ID and an AccessKey secret. The validity period of temporary access credentials is in seconds. The minimum validity period of temporary access credentials is 900 seconds. The maximum validity period of temporary access credentials is the maximum session duration specified for the current role. For more information, see Specify the maximum session duration for a RAM role.

For the complete sample code, visit GitHub.

# -*- coding: utf-8 -*-

from aliyunsdkcore import client
from aliyunsdkcore.request import CommonRequest
import json
import oss2

# Specify the AccessKey pair that is created for the RAM user in Step 1. 
access_key_id = 'yourAccessKeyId'
access_key_secret = 'yourAccessKeySecret'
# Specify the ARN of the role that is created in Step 3. Example: acs:ram::175708322470****:role/ramtest. 
role_arn = 'acs:ram::175708322470****:role/ramtest'

# Create a RAM policy. 
# The policy specifies that the PutObject and GetObject operations can be performed only on resources in a bucket named examplebucket. 
policy_text = '{"Version": "1", "Statement": [{"Action": ["oss:PutObject","oss:GetObject"], "Effect": "Allow", "Resource": ["acs:oss:*:*:examplebucket/*"]}]}'

clt = client.AcsClient(access_key_id, access_key_secret, 'cn-hangzhou')
request = CommonRequest(product="Sts", version='2015-04-01', action_name='AssumeRole')
request.set_method('POST')
request.set_protocol_type('https')
request.add_query_param('RoleArn', role_arn)
# Specify a custom role session name to distinguish different tokens. Example: sessiontest. 
request.add_query_param('RoleSessionName', 'sessiontest')
# Specify the validity period of the temporary access credentials. Unit: seconds. Valid values: 900 to 3600. 
request.add_query_param('DurationSeconds', '3000')
# If you do not configure the RAM policy, the RAM user is granted all permissions of the role. If you have specific requirements on the permissions, refer to the preceding configurations of policy_text. 
request.add_query_param('Policy', policy_text)
request.set_accept_format('JSON')

body = clt.do_action_with_exception(request)

# Use the AccessKey pair of the RAM user to apply for temporary access credentials from STS. 
token = json.loads(oss2.to_unicode(body))
# Display the AccessKey ID, the AccessKey secret, the security token, and the expiration time of the temporary access credentials returned by STS. 
print('AccessKeyId: ' + token['Credentials']['AccessKeyId'])
print('AccessKeySecret: ' + token['Credentials']['AccessKeySecret'])
print('SecurityToken: ' + token['Credentials']['SecurityToken'])
print('Expiration: ' + token['Credentials']['Expiration'])

• Use the temporary access credentials to upload objects to OSS

  # -*- coding: utf-8 -*-
  import oss2
  
  # 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. 
  endpoint = 'https://oss-cn-hangzhou.aliyuncs.com'
  # Specify the temporary AccessKey pair obtained from STS. 
  sts_access_key_id = 'yourAccessKeyId'
  sts_access_key_secret = 'yourAccessKeySecret'
  # Specify the name of the bucket. 
  bucket_name = 'examplebucket'
  # Specify the full path of the object and the string that you want to upload. Do not include the bucket name in the full path. 
  object_name = 'exampleobject.txt'
  # Specify the security token obtained from STS. 
  security_token = 'yourSecurityToken'
  
  
  # Initialize the StsAuth instance based on the authentication information in the temporary access credentials. 
  auth = oss2.StsAuth(sts_access_key_id,
                      sts_access_key_secret,
                      security_token)
  
  # Initialize the bucket by using the StsAuth instance. 
  bucket = oss2.Bucket(auth, endpoint, bucket_name)
  
  # Upload the object. 
  result = bucket.put_object(object_name, "hello world")
  print(result.status)

• Use the temporary access credentials to download objects from OSS

  # -*- coding: utf-8 -*-
  import oss2
  
  # 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. 
  endpoint = 'https://oss-cn-hangzhou.aliyuncs.com'
  # Specify the temporary AccessKey pair obtained from STS. 
  sts_access_key_id = 'yourAccessKeyId'
  sts_access_key_secret = 'yourAccessKeySecret'
  # Specify the name of the bucket. Example: examplebucket. 
  bucket_name = 'examplebucket'
  # Specify the full path of the object and the string that you want to download. Do not include the bucket name in the full path. 
  object_name = 'exampleobject.txt'
  # Specify the security token obtained from STS. 
  security_token = 'yourSecurityToken'
  
  # Initialize the StsAuth instance based on the authentication information in the temporary access credentials. 
  auth = oss2.StsAuth(sts_access_key_id,
                      sts_access_key_secret,
                      security_token)
  
  # Initialize the bucket by using the StsAuth instance. 
  bucket = oss2.Bucket(auth, endpoint, bucket_name)
  
  # Download the object. 
  read_obj = bucket.get_object(object_name)
  print(read_obj.read())