User Impersonation

[scott]

Hi,
I am having trouble getting Impersonation to work. Using Drill 1.7, I have
a drill user, user1, and user2. Drill is started as the drill user. I am
testing impersonation on the local file system dfs default storage plugin
on a linux server. I have setup some files that are owned by user1 and
user2 with 600 permissions, and am using the sqlline tool to test access.
However, I am not able to access either file logged in as user1 or user2.
Only when I change permissions so that the drill user can read am I able to
access either file. I have confirmed that impersonation is enabled using
the following:

 select * from sys.boot where name like '%impersonation%';
+-------------------------------------------------+----------+-------+---------+----------+-------------+-----------+------------+
|                      name                       |   kind   | type  |
status  | num_val  | string_val  | bool_val  | float_val  |
+-------------------------------------------------+----------+-------+---------+----------+-------------+-----------+------------+
| drill.exec.impersonation.enabled                | BOOLEAN  | BOOT  |
BOOT    | null     | null        | true      | null       |
| drill.exec.impersonation.max_chained_user_hops  | LONG     | BOOT  |
BOOT    | 2        | null        | null      | null       |
+-------------------------------------------------+----------+-------+---------+----------+-------------+-----------+------------+

My override conf is:
drill.exec: {
  cluster-id: "mydrillbits",
  zk: {
    connect: "10.80.22.238:2181",
    root: "drill",
    refresh: 500,
    timeout: 5000,
    retry: {
      count: 7200,
      delay: 500
    }
  },
  http: {
    enabled: true,
    ssl_enabled: true,
    port: 8047
  },
  impersonation: {
    enabled: true,
    max_chained_user_hops: 2
  },
  security.user.auth {
    enabled: true,
    packages += "org.apache.drill.exec.rpc.user.security",
    impl: "pam",
    pam_profiles: [ "sudo", "login" ]
  }
}


Has anyone had similar problems, or am I misunderstanding how user
impersonation works?

Thanks for your time,
Scott