Updated on 2022-09-05 GMT+08:00

Creating a Custom Policy

You can create custom policies to supplement system-defined policies and implement more refined access control.

You can create custom policies in either of the following ways:

  • Visual editor: Select a cloud service, specify actions and resources, and add request conditions. You do not need to have knowledge of JSON syntax.
  • JSON: Create a policy in the JSON format from scratch or based on an existing policy.

Creating a Custom Policy in the Visual Editor

  1. Log in to the IAM console.
  2. On the IAM console, choose Permissions from the navigation pane, and click Create Custom Policy in the upper right corner.
  3. Enter a policy name.
  4. Select a scope based on the type of services related to this policy. For more information about service types, see "Permissions".

    • Global services: Select this option if the services to which the policy is related must be deployed in the Global region. When creating custom policies for globally deployed services, specify the scope as Global services. Custom policies of this scope must be attached to user groups for the global service project.
    • Project-level services: Select this option if the services to which the policy is related must be deployed in specific regions. When creating custom policies for regionally deployed services, specify the scope as Project-level services. Custom policies of this scope must be attached to user groups for specific projects except the global service project.

    For example, when creating a custom policy containing the action evs:volumes:create for EVS, specify the scope as Project-level services.

    A custom policy can contain actions of multiple services that are globally accessible or accessible through region-specific projects. To define permissions required to access both global and project-level services, create two custom policies and specify the scope as Global services and Project-level services respectively.

  5. Select Visual editor for Policy View.
  6. Set the policy content.

    1. Select Allow or Deny.
    2. Select a cloud service.
      • Only one cloud service can be selected for each permission block. To configure permissions for multiple cloud services, click Add Permissions, or switch to the JSON view (see Creating a Custom Policy in JSON View).
      • A custom policy can contain permissions for either global or project-level services. To define permissions required to access both global and project-level services, enclose the permissions in two separate policies for refined authorization.
    3. Select actions.
    4. (Optional) Select all resources, or select specific resources by specifying their paths.
      Table 1 Resource type

      Parameter

      Description

      Specific

      Permissions for specific resources. For example, to define permissions for buckets whose names start with TestBucket, specify the bucket resource path as OBS:*:*:bucket:TestBucket*.

      NOTE:
      • Specifying bucket resources

      Format: "OBS:*:*:bucket:Bucket name".

      For bucket resources, IAM automatically generates the prefix of the resource path: obs:*:*:bucket:. For the path of a specific bucket, add the bucket name to the end. You can also use a wildcard character (*) to indicate any bucket. For example, obs:*:*:bucket:* indicates any OBS bucket.

      • Specifying object resources

      Format: "OBS:*:*:object:Bucket name or object name".

      For object resources, IAM automatically generates the prefix of the resource path: obs:*:*:object:. For the path of a specific object, add the bucket name/object name to the end of the resource path. You can also use a wildcard character (*) to indicate any object in a bucket. For example, obs:*:*:object:my-bucket/my-object/* indicates any object in the my-object directory of the my-bucket bucket.

      All

      Permissions for all resources.

    5. (Optional) Add request conditions by specifying condition keys, operators, and values.
      Table 2 Condition parameters

      Name

      Description

      Condition Key

      A key in the Condition element of a statement. There are global and service-level condition keys. Global condition keys (starting with g:) are available for operations of all services, whereas service-level condition keys (starting with a service abbreviation name such as obs:) are available only for operations of the corresponding service. For details, see the user guide of the corresponding cloud service.

      Operator

      Used together with a condition key and condition value to form a complete condition statement.

      Value

      Used together with a condition key and an operator that requires a keyword, to form a complete condition statement.

      Table 3 Global condition keys

      Global Condition Key

      Type

      Description

      g:CurrentTime

      Time

      Time when an authentication request is received. The time is expressed in the format defined by ISO 8601, for example, 2012-11-11T23:59:59Z.

      g:DomainName

      String

      Account name.

      g:MFAPresent

      Boolean

      Whether to obtain a token through MFA authentication.

      g:MFAAge

      Number

      Validity period of a token obtained through MFA authentication. This condition must be used together with g:MFAPresent.

      g:ProjectName

      String

      Project name.

      g:ServiceName

      String

      Service name.

      g:UserId

      String

      IAM user ID.

      g:UserName

      String

      IAM user name.

  7. (Optional) Switch to the JSON view and modify the policy content in the JSON format.

    If the modified policy content is incorrect, check and modify the content again, or click Reset to cancel the modifications.

  8. (Optional) To add another permission block for the policy, click Add Permissions. Alternatively, click the plus (+) icon on the right of an existing permission block to clone its permissions.
  9. (Optional) Enter a brief description for the policy.
  10. Click OK.
  11. Attach the policy to a user group. Users in the group then inherit the permissions defined in this policy.

    You can attach custom policies to a user group in the same way as you attach system-defined policies. For details, see Creating a User Group and Assigning Permissions.

Creating a Custom Policy in JSON View

  1. Log in to the IAM console.
  2. On the IAM console, choose Permissions from the navigation pane, and click Create Custom Policy in the upper right corner.
  3. Enter a policy name.
  4. Select a scope based on the type of services related to this policy. For more information about service types, see "Permissions".

    • Global services: Select this option if the services to which the policy is related must be deployed in the Global region. When creating custom policies for globally deployed services, specify the scope as Global services. Custom policies of this scope must be attached to user groups for the global service project.
    • Project-level services: Select this option if the services to which the policy is related must be deployed in specific regions. When creating custom policies for regionally deployed services, specify the scope as Project-level services. Custom policies of this scope must be attached to user groups for specific projects except the global service project.

    For example, when creating a custom policy containing the action evs:volumes:create for EVS, specify the scope as Project-level services.

    A custom policy can contain actions of multiple services that are globally accessible or accessible through region-specific projects. To define permissions required to access both global and project-level services, create two custom policies and specify the scope as Global services and Project-level services respectively.

  5. Select JSON for Policy View.
  6. (Optional) Click Select Existing Policy/Role, and select a policy/role to use it as a template, for example, select EVS Admin.

    If you select multiple policies, all of them must have the same scope, that is, either Global services or Project-level services. To define permissions required to access both global and project-level services, enclose the permissions in two separate custom policies for refined authorization.

  7. Click OK.
  8. Modify the statement in the template.

    • Effect: Set it to Allow or Deny.
    • Action: Enter the actions listed in the API actions table (see Figure 1) of the EVS service, for example, evs:volumes:create.
      Figure 1 API actions

      The version of each custom policy is fixed at 1.1.

  9. (Optional) Enter a brief description for the policy.
  10. Click OK. If the policy list is displayed, the policy is created successfully. If a message indicating incorrect policy content is displayed, modify the policy.
  11. Attach the policy to a user group. Users in the group then inherit the permissions defined in this policy.

    You can attach custom policies to a user group in the same way as you attach system-defined policies. For details, see Creating a User Group and Assigning Permissions.