Help Center> Dedicated Distributed Storage Service> API Reference> Permissions Policies and Supported Actions> Introduction
Updated on 2022-06-23 GMT+08:00
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Introduction

This chapter describes fine-grained permissions management for your DSS resources. If your Huawei Cloud account does not require individual IAM users, you can skip this chapter.

By default, new IAM users do not have permissions assigned. You need to add a user to one or more groups, and attach permissions policies or roles to these groups. Users inherit permissions from the groups to which they are added and can perform specified operations on cloud services based on the permissions.

You can grant users permissions by using roles and policies. Roles are a type of coarse-grained authorization mechanism that defines permissions related to user responsibilities. Policies define API-based permissions for operations on specific resources under certain conditions, allowing for more fine-grained, secure access control of cloud resources.

Policy-based authorization is useful if you want to allow or deny the access to an API.

An account has all the permissions required to call all APIs, but IAM users must be assigned the required permissions. The permissions required for calling an API are determined by the actions supported by the API. Only users who have been granted permissions allowing the actions can call the API successfully. For example, if an IAM user queries ECSs using an API, the user must have been granted permissions that allow the ecs:servers:list action.

Supported Actions

DSS provides system-defined policies that can be directly used in IAM. You can also create custom policies and use them to supplement system-defined policies, implementing more refined access control. Operations supported by policies are specific to APIs. The following are common concepts related to policies:

  • Permission: A statement in a policy that allows or denies certain operations.
  • APIs: REST APIs that can be called by a user who has been granted specific permissions.
  • Action: Specific operations that are allowed or denied.
  • Related actions: Actions on which a specific action depends to take effect. When assigning permissions for the action to a user, you also need to assign permissions for the dependent actions.
  • IAM projects or enterprise projects: Type of projects in which policies can be used to grant permissions. A policy can be applied to IAM projects, enterprise projects, or both. Policies that contain actions for both IAM and enterprise projects can be used and take effect for both IAM and Enterprise Management. Policies that only contain actions for IAM projects can be used and only take effect for IAM. For details about the differences between IAM and enterprise management, see What Are the Differences Between IAM and Enterprise Management?

DSS supports the following actions that can be defined in custom policies:

  • Storage pool management actions, including actions supported by DSS storage pool management APIs, such as the APIs for querying a DSS storage pool and querying DSS storage pools.
  • Disk management actions, including actions supported by DSS disk management APIs, such as the API for querying details about all disks.