Permissions

New IAM users do not have any permissions assigned by default. You need to first add them to one or more groups and attach policies or roles to these groups. The users then inherit permissions from the groups and can perform specified operations on cloud services based on the permissions they have been assigned.

IMS is a project-level service deployed for specific regions. When you set Scope to Region-specific projects and select the specified projects in the specified regions, the users only have permissions for images in the selected projects. If you set Scope to All resources, the users have permissions for images in all region-specific projects. When accessing IMS, the users need to switch to the authorized region.

You can grant permissions by using roles and policies.

• Roles: A coarse-grained authorization strategy provided by IAM to assign permissions based on users' job responsibilities. Only a limited number of service-level roles are available for authorization. Cloud services depend on each other. When you grant permissions using roles, you also need to attach any existing role dependencies. Roles are not ideal for fine-grained authorization and least privilege access.

  Table 1 System-defined IMS roles

  Role	Description	Dependencies
  IMS Administrator	Administrator permissions for IMS	This role depends on the Tenant Administrator role.
  Server Administrator	Permissions for creating, deleting, querying, modifying, and uploading images	This role depends on the IMS Administrator role in the same project.

• Policies (recommended): A fine-grained authorization strategy that defines permissions required to perform operations on specific cloud resources under certain conditions. This type of authorization is more flexible and is ideal for least privilege access. For example, you can grant users only the permission to manage images of a certain type.

  A majority of fine-grained policies contain permissions for specific APIs, and permissions are defined using API actions. For the API actions supported by IMS, see Permissions and Supported Actions.

  Table 2 System-defined policies for IMS

  Policy	Description	Dependencies
  IMS FullAccess	All permissions for IMS	None
  IMS ReadOnlyAccess	Read-only permissions for IMS. Users with these permissions can only view IMS data.	None

Table 3 lists the common operations supported by system-defined permissions for IMS.

• IAM Service Overview