Overview of managing access permissions to your Amazon Directory Service resources
Every Amazon resource is owned by an Amazon account, and permissions to create or access the resources are governed by permissions policies. An account administrator can attach permissions policies to IAM identities (that is, users, groups, and roles), and some services (such as Amazon Lambda) also support attaching permissions policies to resources.
Note
An account administrator (or administrator user) is a user with administrator privileges. For more information, see IAM best practices in the IAM User Guide.
Topics
Amazon Directory Service resources and operations
In Amazon Directory Service, the primary resource is a directory. Amazon Directory Service supports directory snapshot resources as well. However, you can create snapshots only in the context of an existing directory. Therefore, a snapshot is referred to as a subresource.
These resources have unique Amazon Resource Names (ARNs) associated with them as shown in the following table.
| Resource Type | ARN Format |
|---|---|
|
Directory |
|
|
Snapshot |
|
Amazon Directory Service provides a set of operations to work with the appropriate resources. For a list of available operations, see Directory Service Actions.
Understanding resource ownership
A resource owner is the Amazon account that created a resource. That is, the resource owner is the Amazon account of the principal entity (the root account, an IAM user, or an IAM role) that authenticates the request that creates the resource. The following examples illustrate how this works:
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If you use the root account credentials of your Amazon account to create an Amazon Directory Service resource, such as a directory, your Amazon account is the owner of that resource.
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If you create an IAM user in your Amazon account and grant permissions to create Amazon Directory Service resources to that user, the user can also create Amazon Directory Service resources. However, your Amazon account, to which the user belongs, owns the resources.
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If you create an IAM role in your Amazon account with permissions to create Amazon Directory Service resources, anyone who can assume the role can create Amazon Directory Service resources. Your Amazon account, to which the role belongs, owns the Amazon Directory Service resources.
Managing access to resources
A permissions policy describes who has access to what. The following section explains the available options for creating permissions policies.
Note
This section discusses using IAM in the context of Amazon Directory Service. It doesn't provide detailed information about the IAM service. For complete IAM documentation, see What is IAM? in the IAM User Guide. For information about IAM policy syntax and descriptions, see IAM JSON policy reference in the IAM User Guide.
Policies attached to an IAM identity are referred to as identity-based policies (IAM polices) and policies attached to a resource are referred to as resource-based policies. Amazon Directory Service supports only identity-based policies (IAM policies).
Identity-based policies (IAM policies)
You can attach policies to IAM identities. For example, you can do the following:
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Attach a permissions policy to a user or a group in your account – An account administrator can use a permissions policy that is associated with a particular user to grant permissions for that user to create an Amazon Directory Service resource, such as a new directory.
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Attach a permissions policy to a role (grant cross-account permissions) – You can attach an identity-based permissions policy to an IAM role to grant cross-account permissions.
For more information about using IAM to delegate permissions, see Access management in the IAM User Guide.
The following permissions policy grants permissions to a user to run all of
the actions that begin with Describe. These actions show
information about an Amazon Directory Service resource, such as a directory or snapshot. Note that
the wildcard character (*) in the Resource element indicates that
the actions are allowed for all Amazon Directory Service resources owned by the account.
{ "Version":"2012-10-17", "Statement":[ { "Effect":"Allow", "Action":"ds:Describe*", "Resource":"*" } ] }
For more information about using identity-based policies with Amazon Directory Service, see Using identity-based policies (IAM policies) for Amazon Directory Service. For more information about users, groups, roles, and permissions, see Identities (users, groups, and roles) in the IAM User Guide.
Resource-based policies
Other services, such as Amazon S3, also support resource-based permissions policies. For example, you can attach a policy to an S3 bucket to manage access permissions to that bucket. Amazon Directory Service doesn't support resource-based policies.
Specifying policy elements: Actions, effects, resources, and principals
For each Amazon Directory Service resource, the service defines a set of API operations. For more information, see Amazon Directory Service resources and operations. For a list of available API operations, see Directory Service Actions.
To grant permissions for these API operations, Amazon Directory Service defines a set of actions that you can specify in a policy. Note that performing an API operation can require permissions for more than one action.
The following are the basic policy elements:
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Resource – In a policy, you use an Amazon Resource Name (ARN) to identify the resource to which the policy applies. For Amazon Directory Service resources, you always use the wildcard character (*) in IAM policies. For more information, see Amazon Directory Service resources and operations.
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Action – You use action keywords to identify resource operations that you want to allow or deny. For example, the
ds:DescribeDirectoriespermission allows the user permissions to perform the Amazon Directory ServiceDescribeDirectoriesoperation. -
Effect – You specify the effect when the user requests the specific action. This can be either allow or deny. If you don't explicitly grant access to (allow) a resource, access is implicitly denied. You can also explicitly deny access to a resource, which you might do to make sure that a user cannot access it, even if a different policy grants access.
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Principal – In identity-based policies (IAM policies), the user that the policy is attached to is the implicit principal. For resource-based policies, you specify the user, account, service, or other entity that you want to receive permissions (applies to resource-based policies only). Amazon Directory Service doesn't support resource-based policies.
To learn more about IAM policy syntax and descriptions, see IAM JSON policy reference in the IAM User Guide.
For a table showing all of the Amazon Directory Service API actions and the resources that they apply to, see Amazon Directory Service API permissions: Actions, resources, and conditions reference.
Specifying conditions in a policy
When you grant permissions, you can use the access policy language to specify the conditions when a policy should take effect. For example, you might want a policy to be applied only after a specific date. For more information about specifying conditions in a policy language, see Condition in the IAM User Guide.
To express conditions, you use predefined condition keys. There are no condition keys specific to Amazon Directory Service. However, there are Amazon condition keys that you can use as appropriate. For a complete list of Amazon keys, see Available global condition keys in the IAM User Guide.