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 asscociated 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 rm --role-name={role-name}

Request Parameters

role-name

Description:Name of the role.
Type:String

For example:

radosgw-admin role rm --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 rm --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

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”