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Introduction

This section describes fine-grained permissions management for your IMS. If your HUAWEI CLOUD account does not need individual IAM users, you may skip over this section.

By default, new IAM users do not have any permissions granted. You need to add a user to one or more groups, and assign policies or roles to these groups. The user then inherits permissions from the groups it is a member of. This process is called authorization. After authorization, the user can perform specified operations on BMS based on the permissions.

You can grant users permissions by using roles and policies. Roles are provided by IAM to define service-based permissions depending on users' job 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.

A HUAWEI CLOUD account has all of the permissions required to call all APIs, but IAM users must have the required permissions specifically assigned. The permissions required for calling an API are determined by the actions supported by the API. Only users that have been granted permissions allowing the actions can call the API successfully. For example, if an IAM user queries images using an API, the user must have been granted permissions that allow the ims:images:list action.

Supported Actions

BMS 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. Actions 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 in a custom policy.
  • Actions: Added to a custom policy to control permissions for specific operations.
  • Dependent actions: When assigning an action to users, you also need to assign dependent permissions for that action to take effect.
  • IAM project/Enterprise project: A custom policy can be applied to IAM projects or enterprise projects or both. Policies that contain actions supporting both IAM and enterprise projects can be assigned to user groups and take effect in both IAM and Enterprise Management. Policies that only contain actions supporting IAM projects can be assigned to user groups and only take effect for IAM. Such policies will not take effect if they are assigned to user groups in Enterprise Management. For details about the differences between IAM and enterprise projects, see Differences Between IAM Projects and Enterprise Projects.

√: supported; x: not supported

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

  • Image Management, including actions supported by IMS's image management APIs, such as the APIs for querying images, updating image information, creating images, registering images, and exporting images.
  • Image Tagging, including actions supported by IMS's tag management APIs, such as the APIs for adding tags, deleting tags, and querying images.
  • Image Schema, including actions supported by IMS's image schema management APIs, such as the APIs for querying an image schema, querying an image list schema, querying an image member schema, and query an image member list schema.
  • Image Sharing, including actions supported by IMS's shared image APIs, such as the APIs for adding an image member, updating the status of image members, querying image member details, and deleting an image member.
  • Image Replication, including actions supported by IMS's image replication APIs, such as the API for replicating an image within a region.
  • Image Quota, including actions supported by IMS's image quota APIs, such as the API for querying image quotas.

Error messages returned for native OpenStack APIs are in XML format. JSON format of the fine-grained policy is not supported.