Bucket policies - Object Storage Service - Alibaba Cloud Documentation Center

Bucket policies are resource-based authorization policies. You can use bucket policies to grant other users the permissions to access specific resources in Object Storage Service (OSS).

Usage notes

In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS by using other Alibaba Cloud services in the same region as OSS, use an internal endpoint. For more information about the regions and endpoints supported by OSS, 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.
In this topic, an OSSClient instance is created by using an OSS endpoint. If you want to create an OSSClient instance by using custom domain names or Security Token Service (STS), see Initialization.
To configure a bucket policy, you must have the oss:PutBucketPolicy permission. To query a bucket policy, you must have the oss:GetBucketPolicy permission. To delete a bucket policy, you must have the oss:DeleteBucketPolicy permission. For more information, see Common examples of RAM policies.

Configure a bucket policy

The following sample code provides an example on how to configure a bucket policy:

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

import oss2
from oss2.credentials import EnvironmentVariableCredentialsProvider
import json

# 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. 
auth = oss2.ProviderAuth(EnvironmentVariableCredentialsProvider())
# In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
# Specify the name of the bucket. 
bucket = oss2.Bucket(auth, 'http://oss-cn-hangzhou.aliyuncs.com', 'yourBucketName')

# Specify policy_text. 
policy_text = '{"Statement": [{"Effect": "Allow", "Action": ["oss:GetObject", "oss:ListObjects"], "Resource": ["acs:oss:*:174649585760xxxx:examplebucket/*"]}], "Version": "1"}'

# Configure the bucket policy. 
bucket.put_bucket_policy(policy_text)

Query a bucket policy

The following sample code provides an example on how to query a bucket policy:

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

import oss2
from oss2.credentials import EnvironmentVariableCredentialsProvider
import json
# 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. 
auth = oss2.ProviderAuth(EnvironmentVariableCredentialsProvider())
# In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
# Specify the name of the bucket. 
bucket = oss2.Bucket(auth, 'http://oss-cn-hangzhou.aliyuncs.com', 'yourBucketName')

# Query the policy configured for the bucket. 
result = bucket.get_bucket_policy()
policy_json = json.loads(result.policy) 
print("Get policy text: ", policy_json)

Delete a bucket policy

The following sample code provides an example on how to delete a bucket policy:

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

import oss2
from oss2.credentials import EnvironmentVariableCredentialsProvider
# 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. 
auth = oss2.ProviderAuth(EnvironmentVariableCredentialsProvider())
# In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
# Specify the name of the bucket. 
bucket = oss2.Bucket(auth, 'http://oss-cn-hangzhou.aliyuncs.com', 'yourBucketName')

# Delete the policy configured for the bucket. 
result = bucket.delete_bucket_policy()
assert int(result.status)//100 == 2

References

For the complete sample code for bucket policies, visit GitHub.
For more information about the API operation that you can call to configure a bucket policy, see PutBucketPolicy.
For more information about the API operation that you can call to query a bucket policy, see GetBucketPolicy.
For more information about the API operation that you can call to delete a bucket policy, see DeleteBucketPolicy.