keystone/api-ref/source/v3/samples/admin/policy-show-response.json

{
    "policy": {
        "blob": {
            "foobar_user": [
                "role:compute-user"
            ]
        },
        "id": "717273",
        "links": {
            "self": "http://example.com/identity/v3/policies/717273"
        },
        "type": "application/json"
    }
}