acl: an ACL token can be created referencing the same policy multiple times

[jrasell]

Nomad version

Nomad v1.3.3 (428b2cd8014c48ee9eae23f02712b7219da16d30)

Operating system and Environment details

Tested locally on macOS using a development agent.

Issue

A Nomad ACL token can be created referencing a policy multiple times with the array never being deduplicated. This results in the duplicate policies being shown via the CLI and API and means the internal resolve token functions have extra work than is necessary.

Reproduction steps

1. Run a development agent using the following config snippet to ensure ACLs are enabled:

acl {
  enabled = true
}

2. Bootstrap the ACL system via the nomad acl boostrap command.

3. Create an ACL policy using the example policy below via the nomad acl policy apply -token=<root_token> test <file_path>:

node {
  policy = "read"
}

4. Create an ACL token referencing the created policy multiple times by running nomad acl token create -policy=test -policy=test

Expected Result

The policy name array is deduplicated before being written to state.

Actual Result

The token create output shows the policy link duplicated:

Accessor ID  = <accessor_id>
Secret ID    = <secret_id>
Name         = <none>
Type         = client
Global       = false
Policies     = [test test]
Create Time  = 2022-08-10 07:18:23.87098 +0000 UTC
Create Index = 20
Modify Index = 20