使用 AWS 开发工具包创建只读和读写 IAM 用户

以下代码示例显示如何创建用户并将策略附加到用户。

警告

为了避免安全风险，在开发专用软件或处理真实数据时，请勿使用 IAM 用户进行身份验证。而是使用与身份提供商的联合身份验证，例如 AWS IAM Identity Center。

• 创建两个 IAM 用户。

• 附加一项策略，让一个用户获取对象并将其放入 Amazon S3 存储桶中。

• 附加一项策略，让另一个用户从该存储桶获取对象。

• 根据用户凭证获取对存储桶的不同权限。

Python

SDK for Python (Boto3)

注意

查看 GitHub，了解更多信息。查找完整示例，学习如何在 AWS 代码示例存储库中进行设置和运行。

创建包装 IAM 用户操作的函数。

import logging
import time

import boto3
from botocore.exceptions import ClientError

import access_key_wrapper
import policy_wrapper

logger = logging.getLogger(__name__)
iam = boto3.resource("iam")

def create_user(user_name):
    """
    Creates a user. By default, a user has no permissions or access keys.

    :param user_name: The name of the user.
    :return: The newly created user.
    """
    try:
        user = iam.create_user(UserName=user_name)
        logger.info("Created user %s.", user.name)
    except ClientError:
        logger.exception("Couldn't create user %s.", user_name)
        raise
    else:
        return user



def update_user(user_name, new_user_name):
    """
    Updates a user's name.

    :param user_name: The current name of the user to update.
    :param new_user_name: The new name to assign to the user.
    :return: The updated user.
    """
    try:
        user = iam.User(user_name)
        user.update(NewUserName=new_user_name)
        logger.info("Renamed %s to %s.", user_name, new_user_name)
    except ClientError:
        logger.exception("Couldn't update name for user %s.", user_name)
        raise
    return user



def list_users():
    """
    Lists the users in the current account.

    :return: The list of users.
    """
    try:
        users = list(iam.users.all())
        logger.info("Got %s users.", len(users))
    except ClientError:
        logger.exception("Couldn't get users.")
        raise
    else:
        return users



def delete_user(user_name):
    """
    Deletes a user. Before a user can be deleted, all associated resources,
    such as access keys and policies, must be deleted or detached.

    :param user_name: The name of the user.
    """
    try:
        iam.User(user_name).delete()
        logger.info("Deleted user %s.", user_name)
    except ClientError:
        logger.exception("Couldn't delete user %s.", user_name)
        raise



def attach_policy(user_name, policy_arn):
    """
    Attaches a policy to a user.

    :param user_name: The name of the user.
    :param policy_arn: The Amazon Resource Name (ARN) of the policy.
    """
    try:
        iam.User(user_name).attach_policy(PolicyArn=policy_arn)
        logger.info("Attached policy %s to user %s.", policy_arn, user_name)
    except ClientError:
        logger.exception("Couldn't attach policy %s to user %s.", policy_arn, user_name)
        raise



def detach_policy(user_name, policy_arn):
    """
    Detaches a policy from a user.

    :param user_name: The name of the user.
    :param policy_arn: The Amazon Resource Name (ARN) of the policy.
    """
    try:
        iam.User(user_name).detach_policy(PolicyArn=policy_arn)
        logger.info("Detached policy %s from user %s.", policy_arn, user_name)
    except ClientError:
        logger.exception(
            "Couldn't detach policy %s from user %s.", policy_arn, user_name
        )
        raise

创建包装 IAM policy 操作的函数。

import json
import logging
import operator
import pprint
import time

import boto3
from botocore.exceptions import ClientError

logger = logging.getLogger(__name__)
iam = boto3.resource("iam")

def create_policy(name, description, actions, resource_arn):
    """
    Creates a policy that contains a single statement.

    :param name: The name of the policy to create.
    :param description: The description of the policy.
    :param actions: The actions allowed by the policy. These typically take the
                    form of service:action, such as s3:PutObject.
    :param resource_arn: The Amazon Resource Name (ARN) of the resource this policy
                         applies to. This ARN can contain wildcards, such as
                         'arn:aws:s3:::my-bucket/*' to allow actions on all objects
                         in the bucket named 'my-bucket'.
    :return: The newly created policy.
    """
    policy_doc = {
        "Version": "2012-10-17",
        "Statement": [{"Effect": "Allow", "Action": actions, "Resource": resource_arn}],
    }
    try:
        policy = iam.create_policy(
            PolicyName=name,
            Description=description,
            PolicyDocument=json.dumps(policy_doc),
        )
        logger.info("Created policy %s.", policy.arn)
    except ClientError:
        logger.exception("Couldn't create policy %s.", name)
        raise
    else:
        return policy



def delete_policy(policy_arn):
    """
    Deletes a policy.

    :param policy_arn: The ARN of the policy to delete.
    """
    try:
        iam.Policy(policy_arn).delete()
        logger.info("Deleted policy %s.", policy_arn)
    except ClientError:
        logger.exception("Couldn't delete policy %s.", policy_arn)
        raise

创建包装 IAM 访问密钥操作的函数。

import logging
import boto3
from botocore.exceptions import ClientError

logger = logging.getLogger(__name__)

iam = boto3.resource("iam")

def create_key(user_name):
    """
    Creates an access key for the specified user. Each user can have a
    maximum of two keys.

    :param user_name: The name of the user.
    :return: The created access key.
    """
    try:
        key_pair = iam.User(user_name).create_access_key_pair()
        logger.info(
            "Created access key pair for %s. Key ID is %s.",
            key_pair.user_name,
            key_pair.id,
        )
    except ClientError:
        logger.exception("Couldn't create access key pair for %s.", user_name)
        raise
    else:
        return key_pair



def delete_key(user_name, key_id):
    """
    Deletes a user's access key.

    :param user_name: The user that owns the key.
    :param key_id: The ID of the key to delete.
    """

    try:
        key = iam.AccessKey(user_name, key_id)
        key.delete()
        logger.info("Deleted access key %s for %s.", key.id, key.user_name)
    except ClientError:
        logger.exception("Couldn't delete key %s for %s", key_id, user_name)
        raise

使用包装器函数创建具有不同策略的用户，然后使用其凭证访问 Amazon S3 存储桶。

def usage_demo():
    """
    Shows how to manage users, keys, and policies.
    This demonstration creates two users: one user who can put and get objects in an
    Amazon S3 bucket, and another user who can only get objects from the bucket.
    The demo then shows how the users can perform only the actions they are permitted
    to perform.
    """
    logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")
    print("-" * 88)
    print("Welcome to the AWS Identity and Account Management user demo.")
    print("-" * 88)
    print(
        "Users can have policies and roles attached to grant them specific "
        "permissions."
    )
    s3 = boto3.resource("s3")
    bucket = s3.create_bucket(
        Bucket=f"demo-iam-bucket-{time.time_ns()}",
        CreateBucketConfiguration={
            "LocationConstraint": s3.meta.client.meta.region_name
        },
    )
    print(f"Created an Amazon S3 bucket named {bucket.name}.")
    user_read_writer = create_user("demo-iam-read-writer")
    user_reader = create_user("demo-iam-reader")
    print(f"Created two IAM users: {user_read_writer.name} and {user_reader.name}")
    update_user(user_read_writer.name, "demo-iam-creator")
    update_user(user_reader.name, "demo-iam-getter")
    users = list_users()
    user_read_writer = next(
        user for user in users if user.user_id == user_read_writer.user_id
    )
    user_reader = next(user for user in users if user.user_id == user_reader.user_id)
    print(
        f"Changed the names of the users to {user_read_writer.name} "
        f"and {user_reader.name}."
    )

    read_write_policy = policy_wrapper.create_policy(
        "demo-iam-read-write-policy",
        "Grants rights to create and get an object in the demo bucket.",
        ["s3:PutObject", "s3:GetObject"],
        f"arn:aws:s3:::{bucket.name}/*",
    )
    print(
        f"Created policy {read_write_policy.policy_name} with ARN: {read_write_policy.arn}"
    )
    print(read_write_policy.description)
    read_policy = policy_wrapper.create_policy(
        "demo-iam-read-policy",
        "Grants rights to get an object from the demo bucket.",
        "s3:GetObject",
        f"arn:aws:s3:::{bucket.name}/*",
    )
    print(f"Created policy {read_policy.policy_name} with ARN: {read_policy.arn}")
    print(read_policy.description)
    attach_policy(user_read_writer.name, read_write_policy.arn)
    print(f"Attached {read_write_policy.policy_name} to {user_read_writer.name}.")
    attach_policy(user_reader.name, read_policy.arn)
    print(f"Attached {read_policy.policy_name} to {user_reader.name}.")

    user_read_writer_key = access_key_wrapper.create_key(user_read_writer.name)
    print(f"Created access key pair for {user_read_writer.name}.")
    user_reader_key = access_key_wrapper.create_key(user_reader.name)
    print(f"Created access key pair for {user_reader.name}.")

    s3_read_writer_resource = boto3.resource(
        "s3",
        aws_access_key_id=user_read_writer_key.id,
        aws_secret_access_key=user_read_writer_key.secret,
    )
    demo_object_key = f"object-{time.time_ns()}"
    demo_object = None
    while demo_object is None:
        try:
            demo_object = s3_read_writer_resource.Bucket(bucket.name).put_object(
                Key=demo_object_key, Body=b"AWS IAM demo object content!"
            )
        except ClientError as error:
            if error.response["Error"]["Code"] == "InvalidAccessKeyId":
                print("Access key not yet available. Waiting...")
                time.sleep(1)
            else:
                raise
    print(
        f"Put {demo_object_key} into {bucket.name} using "
        f"{user_read_writer.name}'s credentials."
    )

    read_writer_object = s3_read_writer_resource.Bucket(bucket.name).Object(
        demo_object_key
    )
    read_writer_content = read_writer_object.get()["Body"].read()
    print(f"Got object {read_writer_object.key} using read-writer user's credentials.")
    print(f"Object content: {read_writer_content}")

    s3_reader_resource = boto3.resource(
        "s3",
        aws_access_key_id=user_reader_key.id,
        aws_secret_access_key=user_reader_key.secret,
    )
    demo_content = None
    while demo_content is None:
        try:
            demo_object = s3_reader_resource.Bucket(bucket.name).Object(demo_object_key)
            demo_content = demo_object.get()["Body"].read()
            print(f"Got object {demo_object.key} using reader user's credentials.")
            print(f"Object content: {demo_content}")
        except ClientError as error:
            if error.response["Error"]["Code"] == "InvalidAccessKeyId":
                print("Access key not yet available. Waiting...")
                time.sleep(1)
            else:
                raise

    try:
        demo_object.delete()
    except ClientError as error:
        if error.response["Error"]["Code"] == "AccessDenied":
            print("-" * 88)
            print(
                "Tried to delete the object using the reader user's credentials. "
                "Got expected AccessDenied error because the reader is not "
                "allowed to delete objects."
            )
            print("-" * 88)

    access_key_wrapper.delete_key(user_reader.name, user_reader_key.id)
    detach_policy(user_reader.name, read_policy.arn)
    policy_wrapper.delete_policy(read_policy.arn)
    delete_user(user_reader.name)
    print(f"Deleted keys, detached and deleted policy, and deleted {user_reader.name}.")

    access_key_wrapper.delete_key(user_read_writer.name, user_read_writer_key.id)
    detach_policy(user_read_writer.name, read_write_policy.arn)
    policy_wrapper.delete_policy(read_write_policy.arn)
    delete_user(user_read_writer.name)
    print(
        f"Deleted keys, detached and deleted policy, and deleted {user_read_writer.name}."
    )

    bucket.objects.delete()
    bucket.delete()
    print(f"Emptied and deleted {bucket.name}.")
    print("Thanks for watching!")

• 有关 API 详细信息，请参阅《AWS SDK for Python (Boto3) API 参考》中的以下主题。

  • AttachUserPolicy

  • CreateAccessKey

  • CreatePolicy

  • CreateUser

  • DeleteAccessKey

  • DeletePolicy

  • DeleteUser

  • DetachUserPolicy

  • ListUsers

  • UpdateUser

有关 AWS SDK 开发人员指南和代码示例的完整列表，请参阅 将此服务与 AWS SDK 结合使用。本主题还包括有关入门的信息以及有关先前的 SDK 版本的详细信息。