Role
A role is similar to a user and has permission policies attached to it, that determine what a role can or can not do. A role can be assumed by any identity that needs it. If a user assumes a role, a set of dynamically created temporary credentials are returned to the user. A role can be used to delegate access to users, applications, services that do not have permissions to access some s3 resources.
The following radosgw-admin commands can be used to create/ delete/ update a role and permissions associated with a role.
Create a Role
To create a role, execute the following:
radosgw-admin role create --role-name={role-name} [--path=="{path to the role}"] [--assume-role-policy-doc={trust-policy-document}]
Request Parameters
role-name
- Description
Name of the role.
- Type
String
path
- Description
Path to the role. The default value is a slash(/).
- Type
String
assume-role-policy-doc
- Description
The trust relationship policy document that grants an entity permission to assume the role.
- Type
String
For example:
radosgw-admin role create --role-name=S3Access1 --path=/application_abc/component_xyz/ --assume-role-policy-doc=\{\"Version\":\"2012-10-17\",\"Statement\":\[\{\"Effect\":\"Allow\",\"Principal\":\{\"AWS\":\[\"arn:aws:iam:::user/TESTER\"\]\},\"Action\":\[\"sts:AssumeRole\"\]\}\]\}
{
"id": "ca43045c-082c-491a-8af1-2eebca13deec",
"name": "S3Access1",
"path": "/application_abc/component_xyz/",
"arn": "arn:aws:iam:::role/application_abc/component_xyz/S3Access1",
"create_date": "2018-10-17T10:18:29.116Z",
"max_session_duration": 3600,
"assume_role_policy_document": "{\"Version\":\"2012-10-17\",\"Statement\":[{\"Effect\":\"Allow\",\"Principal\":{\"AWS\":[\"arn:aws:iam:::user/TESTER\"]},\"Action\":[\"sts:AssumeRole\"]}]}"
}
Delete a Role
To delete a role, execute the following:
radosgw-admin role delete --role-name={role-name}
Request Parameters
role-name
- Description
Name of the role.
- Type
String
For example:
radosgw-admin role delete --role-name=S3Access1
Note: A role can be deleted only when it doesn’t have any permission policy attached to it.
Get a Role
To get information about a role, execute the following:
radosgw-admin role get --role-name={role-name}
Request Parameters
role-name
- Description
Name of the role.
- Type
String
For example:
radosgw-admin role get --role-name=S3Access1
{
"id": "ca43045c-082c-491a-8af1-2eebca13deec",
"name": "S3Access1",
"path": "/application_abc/component_xyz/",
"arn": "arn:aws:iam:::role/application_abc/component_xyz/S3Access1",
"create_date": "2018-10-17T10:18:29.116Z",
"max_session_duration": 3600,
"assume_role_policy_document": "{\"Version\":\"2012-10-17\",\"Statement\":[{\"Effect\":\"Allow\",\"Principal\":{\"AWS\":[\"arn:aws:iam:::user/TESTER\"]},\"Action\":[\"sts:AssumeRole\"]}]}"
}
List Roles
To list roles with a specified path prefix, execute the following:
radosgw-admin role list [--path-prefix ={path prefix}]
Request Parameters
path-prefix
- Description
Path prefix for filtering roles. If this is not specified, all roles are listed.
- Type
String
For example:
radosgw-admin role list --path-prefix="/application"
[
{
"id": "3e1c0ff7-8f2b-456c-8fdf-20f428ba6a7f",
"name": "S3Access1",
"path": "/application_abc/component_xyz/",
"arn": "arn:aws:iam:::role/application_abc/component_xyz/S3Access1",
"create_date": "2018-10-17T10:32:01.881Z",
"max_session_duration": 3600,
"assume_role_policy_document": "{\"Version\":\"2012-10-17\",\"Statement\":[{\"Effect\":\"Allow\",\"Principal\":{\"AWS\":[\"arn:aws:iam:::user/TESTER\"]},\"Action\":[\"sts:AssumeRole\"]}]}"
}
]
Update Assume Role Policy Document of a role
To modify a role’s assume role policy document, execute the following:
radosgw-admin role modify --role-name={role-name} --assume-role-policy-doc={trust-policy-document}
Request Parameters
role-name
- Description
Name of the role.
- Type
String
assume-role-policy-doc
- Description
The trust relationship policy document that grants an entity permission to assume the role.
- Type
String
For example:
radosgw-admin role modify --role-name=S3Access1 --assume-role-policy-doc=\{\"Version\":\"2012-10-17\",\"Statement\":\[\{\"Effect\":\"Allow\",\"Principal\":\{\"AWS\":\[\"arn:aws:iam:::user/TESTER2\"\]\},\"Action\":\[\"sts:AssumeRole\"\]\}\]\}
{
"id": "ca43045c-082c-491a-8af1-2eebca13deec",
"name": "S3Access1",
"path": "/application_abc/component_xyz/",
"arn": "arn:aws:iam:::role/application_abc/component_xyz/S3Access1",
"create_date": "2018-10-17T10:18:29.116Z",
"max_session_duration": 3600,
"assume_role_policy_document": "{\"Version\":\"2012-10-17\",\"Statement\":[{\"Effect\":\"Allow\",\"Principal\":{\"AWS\":[\"arn:aws:iam:::user/TESTER2\"]},\"Action\":[\"sts:AssumeRole\"]}]}"
}
In the above example, we are modifying the Principal from TESTER to TESTER2 in its assume role policy document.
Add/ Update a Policy attached to a Role
To add or update the inline policy attached to a role, execute the following:
radosgw-admin role policy put --role-name={role-name} --policy-name={policy-name} --policy-doc={permission-policy-doc}
Request Parameters
role-name
- Description
Name of the role.
- Type
String
policy-name
- Description
Name of the policy.
- Type
String
policy-doc
- Description
The Permission policy document.
- Type
String
For example:
radosgw-admin role-policy put --role-name=S3Access1 --policy-name=Policy1 --policy-doc=\{\"Version\":\"2012-10-17\",\"Statement\":\[\{\"Effect\":\"Allow\",\"Action\":\[\"s3:*\"\],\"Resource\":\"arn:aws:s3:::example_bucket\"\}\]\}
In the above example, we are attaching a policy ‘Policy1’ to role ‘S3Access1’, which allows all s3 actions on ‘example_bucket’.
List Permission Policy Names attached to a Role
To list the names of permission policies attached to a role, execute the following:
radosgw-admin role policy get --role-name={role-name}
Request Parameters
role-name
- Description
Name of the role.
- Type
String
For example:
radosgw-admin role-policy list --role-name=S3Access1
[
"Policy1"
]
Get Permission Policy attached to a Role
To get a specific permission policy attached to a role, execute the following:
radosgw-admin role policy get --role-name={role-name} --policy-name={policy-name}
Request Parameters
role-name
- Description
Name of the role.
- Type
String
policy-name
- Description
Name of the policy.
- Type
String
For example:
radosgw-admin role-policy get --role-name=S3Access1 --policy-name=Policy1
{
"Permission policy": "{\"Version\":\"2012-10-17\",\"Statement\":[{\"Effect\":\"Allow\",\"Action\":[\"s3:*\"],\"Resource\":\"arn:aws:s3:::example_bucket\"}]}"
}
Delete Policy attached to a Role
To delete permission policy attached to a role, execute the following:
radosgw-admin role policy delete --role-name={role-name} --policy-name={policy-name}
Request Parameters
role-name
- Description
Name of the role.
- Type
String
policy-name
- Description
Name of the policy.
- Type
String
For example:
radosgw-admin role-policy delete --role-name=S3Access1 --policy-name=Policy1
REST APIs for Manipulating a Role
In addition to the above radosgw-admin commands, the following REST APIs can be used for manipulating a role. For the request parameters and their explanations, refer to the sections above.
In order to invoke the REST admin APIs, a user with admin caps needs to be created.
radosgw-admin --uid TESTER --display-name "TestUser" --access_key TESTER --secret test123 user create
radosgw-admin caps add --uid="TESTER" --caps="roles=*"
Create a Role
- Example::
POST “<hostname>?Action=CreateRole&RoleName=S3Access&Path=/application_abc/component_xyz/&AssumeRolePolicyDocument={"Version":"2012-10-17","Statement":[{"Effect":"Allow","Principal":{"AWS":["arn:aws:iam:::user/TESTER"]},"Action":["sts:AssumeRole"]}]}”
<role>
<id>8f41f4e0-7094-4dc0-ac20-074a881ccbc5</id>
<name>S3Access</name>
<path>/application_abc/component_xyz/</path>
<arn>arn:aws:iam:::role/application_abc/component_xyz/S3Access</arn>
<create_date>2018-10-23T07:43:42.811Z</create_date>
<max_session_duration>3600</max_session_duration>
<assume_role_policy_document>{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Principal":{"AWS":["arn:aws:iam:::user/TESTER"]},"Action":["sts:AssumeRole"]}]}</assume_role_policy_document>
</role>
Delete a Role
- Example::
POST “<hostname>?Action=DeleteRole&RoleName=S3Access”
Note: A role can be deleted only when it doesn’t have any permission policy attached to it.
Get a Role
- Example::
POST “<hostname>?Action=GetRole&RoleName=S3Access”
<role>
<id>8f41f4e0-7094-4dc0-ac20-074a881ccbc5</id>
<name>S3Access</name>
<path>/application_abc/component_xyz/</path>
<arn>arn:aws:iam:::role/application_abc/component_xyz/S3Access</arn>
<create_date>2018-10-23T07:43:42.811Z</create_date>
<max_session_duration>3600</max_session_duration>
<assume_role_policy_document>{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Principal":{"AWS":["arn:aws:iam:::user/TESTER"]},"Action":["sts:AssumeRole"]}]}</assume_role_policy_document>
</role>
List Roles
- Example::
POST “<hostname>?Action=ListRoles&RoleName=S3Access&PathPrefix=/application”
<role>
<id>8f41f4e0-7094-4dc0-ac20-074a881ccbc5</id>
<name>S3Access</name>
<path>/application_abc/component_xyz/</path>
<arn>arn:aws:iam:::role/application_abc/component_xyz/S3Access</arn>
<create_date>2018-10-23T07:43:42.811Z</create_date>
<max_session_duration>3600</max_session_duration>
<assume_role_policy_document>{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Principal":{"AWS":["arn:aws:iam:::user/TESTER"]},"Action":["sts:AssumeRole"]}]}</assume_role_policy_document>
</role>
Update Assume Role Policy Document
- Example::
POST “<hostname>?Action=UpdateAssumeRolePolicy&RoleName=S3Access&PolicyDocument={"Version":"2012-10-17","Statement":[{"Effect":"Allow","Principal":{"AWS":["arn:aws:iam:::user/TESTER2"]},"Action":["sts:AssumeRole"]}]}”
Add/ Update a Policy attached to a Role
- Example::
POST “<hostname>?Action=PutRolePolicy&RoleName=S3Access&PolicyName=Policy1&PolicyDocument={"Version":"2012-10-17","Statement":[{"Effect":"Allow","Action":["s3:CreateBucket"],"Resource":"arn:aws:s3:::example_bucket"}]}”
List Permission Policy Names attached to a Role
- Example::
POST “<hostname>?Action=ListRolePolicies&RoleName=S3Access”
<PolicyNames>
<member>Policy1</member>
</PolicyNames>
Get Permission Policy attached to a Role
- Example::
POST “<hostname>?Action=GetRolePolicy&RoleName=S3Access&PolicyName=Policy1”
<GetRolePolicyResult>
<PolicyName>Policy1</PolicyName>
<RoleName>S3Access</RoleName>
<Permission_policy>{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Action":["s3:CreateBucket"],"Resource":"arn:aws:s3:::example_bucket"}]}</Permission_policy>
</GetRolePolicyResult>
Delete Policy attached to a Role
- Example::
POST “<hostname>?Action=DeleteRolePolicy&RoleName=S3Access&PolicyName=Policy1”
Tag a role
A role can have multivalued tags attached to it. These tags can be passed in as part of CreateRole REST API also. AWS does not support multi-valued role tags.
- Example::
POST “<hostname>?Action=TagRole&RoleName=S3Access&Tags.member.1.Key=Department&Tags.member.1.Value=Engineering”
<TagRoleResponse>
<ResponseMetadata>
<RequestId>tx000000000000000000004-00611f337e-1027-default</RequestId>
</ResponseMetadata>
</TagRoleResponse>