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

Log in to the IAM console.
On the IAM console, choose Permissions > Policies from the navigation pane, and click Create Custom Policy in the upper right corner.
Enter a policy name.

Figure 1 Entering a policy name
Select Visual editor for Policy View.

Set the policy content.

Select Allow or Deny.
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.
Select actions.

(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.

(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.

Figure 2 Adding a request condition
Click to enlarge

**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.

(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.
(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.
(Optional) Enter a brief description for the policy.
Click OK.
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

Log in to the IAM console.
On the IAM console, choose Permissions > Policies from the navigation pane, and click Create Custom Policy in the upper right corner.
Enter a policy name.

Figure 3 Entering a policy name
Select JSON for Policy View.
(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.
Click OK.
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 4) of the EVS service, for example, evs:volumes:create.
  Figure 4 API actions
  
  The version of each custom policy is fixed at 1.1.
(Optional) Enter a brief description for the policy.
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.
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.