Copy the updated version of freeport (sdk/freeport), and tweak it for use
in Nomad tests. This means staying below port 10000 to avoid conflicts with
the lib/freeport that is still transitively used by the old version of
consul that we vendor. Also provide implementations to find ephemeral ports
of macOS and Windows environments.
Ports acquired through freeport are supposed to be returned to freeport,
which this change now also introduces. Many tests are modified to include
calls to a cleanup function for Server objects.
This should help quite a bit with some flakey tests, but not all of them.
Our port problems will not go away completely until we upgrade our vendor
version of consul. With Go modules, we'll probably do a 'replace' to swap
out other copies of freeport with the one now in 'nomad/helper/freeport'.
If ACL Request is unauthenticated, we should honor the anonymous token.
This PR makes few changes:
* `GetPolicy` endpoints may return policy if anonymous policy allows it,
or return permission denied otherwise.
* `ListPolicies` returns an empty policy list, or one with anonymous
policy if one exists.
Without this PR, the we return an incomprehensible error.
Before:
```
$ curl http://localhost:4646/v1/acl/policy/doesntexist; echo
acl token lookup failed: index error: UUID must be 36 characters
$ curl http://localhost:4646/v1/acl/policies; echo
acl token lookup failed: index error: UUID must be 36 characters
```
After:
```
$ curl http://localhost:4646/v1/acl/policy/doesntexist; echo
Permission denied
$ curl http://localhost:4646/v1/acl/policies; echo
[]
```
Noticed that ACL endpoints return 500 status code for user errors. This
is confusing and can lead to false monitoring alerts.
Here, I introduce a concept of RPCCoded errors to be returned by RPC
that signal a code in addition to error message. Codes for now match
HTTP codes to ease reasoning.
```
$ nomad acl bootstrap
Error bootstrapping: Unexpected response code: 500 (ACL bootstrap already done (reset index: 9))
$ nomad acl bootstrap
Error bootstrapping: Unexpected response code: 400 (ACL bootstrap already done (reset index: 9))
```
Seth Hoenig